Document:

EX-4.1

 Exhibit 4.1 

XTERA COMMUNICATIONS, INC. 

SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

AUGUST 1, 2007 

 XTERA COMMUNICATIONS, INC. 

SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

This Second Amended and Restated Investor Rights Agreement (the “Agreement”) is made and entered into as
of August 1, 2007 by and among Xtera Communications, Inc., a Delaware corporation (the “Company”), (the “Company”), those certain holders of the Company’s Common Stock set forth on Exhibit
A attached to this Agreement (individually, a “Common Stockholder,” and collectively, the “Common Stockholders”), and the holders of the Series A-1 Convertible Preferred Stock, par value $0.001 per
share (“Series A-1 Preferred Stock”), and the Series B-1 Convertible Preferred Stock, par value $0.001 per share (“Series B-1 Preferred Stock,” and together with the Series A-1 Preferred Stock, the
“Preferred Stock”), of the Company set forth on Exhibit B attached to this Agreement (individually, an “Investor” collectively, the “Investors,” and together with the
Common Stockholders, the “Stockholders”). 
 RECITALS 

The Company and certain of the Investors are parties to the Series B-1 Preferred Stock Purchase Agreement, dated as of the date
of this Agreement (as amended or otherwise modified from time to time, the “Purchase Agreement”), pursuant to which the Company has agreed to sell, and such Investors have agreed to purchase, shares of Series B-1 Preferred
Stock of the Company, subject to certain conditions, including the execution and delivery of this Agreement; 

The Company, certain Common Stockholders and certain of the Investors (the “Existing Stockholders”) have
previously entered into the Amended and Restated Investor Rights Agreement dated as of August 12, 2003 (the “Prior Agreement”); 

The Prior Agreement may be amended, and any provision therein waived, with the consent of the Company, the holders of at least a majority of
the Series A-1 Preferred Stock and the holders of a majority of the Common Stock then outstanding and held by the Existing Stockholders; 

The Company and the Existing Stockholders, as holders of at least a majority of the Series A-1 Preferred Stock and a majority of the Common
Stock then outstanding and held by such Existing Stockholders, desire to amend and restate the Prior Agreement and to accept the rights and obligations created pursuant hereto in lieu of the rights and obligations created under the Prior Agreement;

 To induce the Investors to enter into the Purchase Agreement and purchase shares of Series B-1 Preferred Stock thereunder, the Company,
the Common Stockholders and the Investors desire to enter into this Agreement to set forth certain rights and obligations of the Stockholders; 

NOW, THEREFORE, in consideration of the foregoing recitals and the mutual promises set forth in this Agreement, the parties to this
Agreement agree as follows: 
 1. RIGHTS OF INVESTORS. The Company hereby grants to each Investor the information rights,
registration rights and rights of first offer (collectively the “Investor Rights”) contained herein. Each Investor accepts the Investor Rights, as applicable, and agrees to be bound by the obligations contained herein. 

 2. INFORMATION RIGHTS. 

2.1 Financial Information. The Company will provide each Investor the following reports for so long as such Investor is a holder
of a minimum of 2,000,000 shares of Registrable Securities (as defined in Section 3.1): 
 (a) Annual Reports.
As soon as reasonably practicable after the end of each fiscal year, and in any event within 120 days thereafter, consolidated balance sheets of the Company and its subsidiaries, if any, as of the end of such fiscal year, and consolidated statements
of income, stockholders’ equity and cash flows of the Company and its subsidiaries, if any, for such year, each prepared in accordance with generally accepted accounting principles and setting forth in each case in comparative form the figures
for the previous fiscal year, all in reasonable detail and audited by independent auditors selected by the Company’s Board of Directors. 

(b) Monthly and Quarterly Reports. As soon as practicable after the end of each month and fiscal quarter, and in any
event within thirty (30) days and forty-five (45) days, respectively, thereafter, an unaudited consolidated balance sheet of the Company and its subsidiaries, if any, as of the end of each such period, as well as unaudited consolidated
statements of income and cash flows of the Company and its subsidiaries for such period, and setting forth in each case in comparative form the corresponding figures for the corresponding period of (i) the preceding fiscal year and
(ii) the Company’s budget for such month or quarter, as applicable, all in reasonable detail and prepared in accordance with generally accepted accounting principles (GAAP) consistently applied. 

(c) Annual Budget. As soon as practicable, but in any event thirty (30) days prior to the end of each fiscal year,
a projected operating budget and business plan for the next fiscal year, approved by the Board of Directors, prepared on a monthly basis, including balance sheets, income statements and statements of cash flows for such months and, as soon as
prepared, any other budgets or revised budgets prepared by the Company. 
 (d) Accountant’s Letters. Promptly
following receipt by the Company, each audit response letter, accountant’s management letter and other written report submitted to the Company by its independent public accountants in connection with an annual or interim audit of the books of
the Company or any of its subsidiaries; and 
 (e) Notices. Promptly after the commencement thereof, notice of all
actions, suits, claims, proceedings, investigations, and inquiries that would reasonably be expected to materially and adversely affect the Company or any of its subsidiaries, if any. 

2.2 Inspection. The Company shall permit, and cause each of its subsidiaries, if any, to permit, each Investor and such persons
as each Investor may designate, at such Investor’s expense to visit and inspect the Company’s properties, to examine its books of  

  
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account and records and to discuss the Company’s affairs, finances and accounts with its officers, all at such reasonable times as may be requested by the Investor; provided,
however, that the Company shall not be obligated pursuant to this Section 2.2 to provide access to any information that it reasonably considers to be a trade secret or similar confidential information unless the Investor first
signs a standard form nondisclosure agreement reasonably acceptable to the Company. 
 2.3 Assignment of Rights. The rights
granted pursuant to this Section 2 may be assigned or otherwise conveyed by each Investor to (i) a transferee or assignee who holds, subsequent to such transfer, not less than 2,000,000 shares of Registrable Securities (as defined
in Section 3.1), (ii) a subsidiary, wholly-owned entity, successor entity, parent, affiliate, member or stockholder of a Holder, or (iii) a grantor or beneficiary of a holder of Registrable Securities that is a trust.
Notwithstanding the foregoing, the rights granted pursuant to this Section 2 may not be assigned or otherwise conveyed to a competitor of the Company, as reasonably determined by the Board of Directors of the Company. Each Investor shall
provide the Company with written notice of any proposed assignment or conveyance of the rights granted pursuant to this Section 2, which shall be delivered no less than 10 business days prior to the proposed date of any such transfer.

 2.4 Termination of Certain Rights. The Company’s obligations under this Section 2 will terminate upon
the closing of the Company’s initial public offering of Common Stock pursuant to an effective registration statement filed with and declared effective by the Securities and Exchange Commission (the “SEC”)
under the Securities Act of 1933, as amended (the “Securities Act”), covering the offer and sale of securities for the account of the Corporation to the public (A) at a price per share of Common Stock of
not less than $3.46028 per share (subject to proportionate adjustment in the event of a stock split, reverse stock split, reclassification or stock dividend), (B) with respect to which the Corporation receives aggregate net proceeds (after
deduction of underwriting discounts and commissions) of not less than $75,000,000, and (C) with respect to which such Common Stock is listed for trading on either the New York Stock Exchange or the NASDAQ National Market (the
“Company’s Initial Public Registration”). Notwithstanding the foregoing, the covenant set forth in Sections 2.8 hereof shall continue for so long as any Investor Nominee is a member of the Board of
Directors. 
 2.5 Corporate Existence. The Company shall maintain and cause each of its material operating
subsidiaries, if any, to maintain, their respective corporate existence. 
 2.6 Properties, Business Insurance. The
Company shall obtain and maintain and cause each of its subsidiaries, if any, to maintain as to their respective properties and business, with financially sound and reputable insurers, insurance against such casualties and contingencies and of such
types and in such amounts as is customary for companies similarly situated. 
 2.7 Key Person Insurance. Within 45 days
after the date hereof, the Company shall obtain and shall thereafter use its best efforts to maintain in effect “key person” term life insurance policies of at least $1,000,000 on the life of each of Jon Hopper and Herve Fevrier, which
shall name the Company as beneficiary. 

  
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 2.8 Directors and Officers’ Insurance. The Company shall, as promptly as
practicable following the date hereof, obtain and maintain directors and officers’ liability insurance coverage of at least $3,000,000 per occurrence, covering, among other things, violations of federal or state securities laws. 

2.9 Bylaws. The Company shall at all times cause its Bylaws to provide that unless otherwise required by the laws of the State
of Delaware, any one director shall have the right to call a meeting of the Board of Directors. The Company shall at all times maintain provisions in its By-laws indemnifying all directors against liability and absolving all directors from liability
to the Company and its stockholders to the maximum extent permitted under the laws of the State of Delaware. 
 2.10 Employee
Agreements. The Company shall obtain, and shall cause its subsidiaries, if any, to obtain, an Employee Nondisclosure, Noncompetition and Assignment Agreement in a form approved by the Board of Directors from all future officers and employees
of the Company or any of its subsidiaries, upon their employment by the Company or any of its subsidiaries. The Company shall obtain appropriate confidentiality and invention assignment agreements for consultants contributing to the Company’s
intellectual property. 
 2.11 Compliance with Laws. The Company shall comply, and cause each subsidiary to comply,
with all applicable laws, rules, regulations and orders, noncompliance with which could materially adversely affect its business or condition, financial or otherwise. 

2.12 Lock-Up Agreements. The Company will obtain agreements in writing from each holder of stock or options of the Company, as a
condition to any issuance of stock or grant of options, agreeing not to directly or indirectly offer, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant for
the sale of or otherwise dispose of or transfer any shares of stock without the consent of the Company’s underwriters, in connection with any public offering of the Company’s capital stock, consistent with the provisions of
Section 3.10 below. 
 2.13 Affiliated Transactions. All transactions by and between the Company and any
officer, employee, director or stockholder of the Company or persons controlling, controlled by, under common control with or otherwise affiliated with such officer, employee, director or stockholder shall be conducted on an arm’s-length basis,
shall be on terms and conditions no less favorable to the Company than could be obtained from nonrelated persons. 
 2.14
Publicity. Prior to making any public statements or issuing any press releases with respect to this transaction or otherwise referring to the name “The Wellcome Trust”, the Company shall obtain the prior written approval of The
Wellcome Trust Limited, as Trustee of the Wellcome Trust. Additionally, prior to making any public statements or issuing any press releases with respect to this transaction or otherwise referring to the name “Xtera Communications, Inc.”,
each Investor shall obtain the prior written approval of the Company; provided, however, that the Investors shall not be required to obtain the prior written approval of the Company in order to disclose the name of the Company on their respective
websites and in their disclosures to their respective partners in connection with preparing reports in the ordinary course. 

  
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 3. REGISTRATION RIGHTS. 

3.1 Definitions. 

(a) Exchange Act. The term “Exchange Act” means the Securities Exchange Act of 1934, as amended.

 (b) Form S-3. The term “Form S-3” means such form under the Securities Act as is in effect
on the date hereof or any successor registration form under the Securities Act subsequently adopted by the SEC which permits inclusion or incorporation of substantial information by reference to other documents filed by the Company with the SEC.

 (c) Holder. For purposes of this Section 3, the term “Holder” means any person
owning of record Registrable Securities that have not been sold to the public or pursuant to Rule 144 promulgated under the Securities Act or any assignee of record of such Registrable Securities to whom rights under this Section 3 have
been duly assigned in accordance with this Agreement. “Holder” shall also mean the Regents of the University of Michigan, Comerica Bank, Heller Financial Leasing, Inc. and Silicon Valley Bank, but only for purposes of
Section 3.3 hereof. 
 (d) Initiating Holder. The term “Initiating Holder” shall
mean any Holder or Holders who in the aggregate are Holders of not less than 50% of the then outstanding Registrable Securities which have not been sold to the public. 

(e) Registrable Securities. The term “Registrable Securities” means: (i) all shares of
Common Stock held by any Investor, (ii) all shares of Common Stock issued or issuable pursuant to the conversion of the Preferred Stock, (iii) all shares of Common Stock issued or issuable pursuant to the exercise of warrants to purchase
Common Stock held by any Investor, (iv) solely for purposes of Section 3.3 hereof, 279,505 shares of Common Stock held by the Regents of the University of Michigan, 2,175 shares of Common Stock issued or issuable pursuant to the
exercise of certain warrants to purchase Common Stock held by Comerica Bank, 329 shares of Common Stock issued or issuable pursuant to the exercise of a warrant to purchase Common Stock held by Heller Financial Leasing, Inc., 221,402 shares of
Series A-1 Preferred Stock issued or issuable pursuant to the exercise of a warrant to purchase Series A-1 Preferred Stock held by Horizon Technology Funding Company II LLC and 221,402 shares of Series A-1 Preferred Stock issued or issuable pursuant
to the exercise of a warrant to purchase Series A-1 Preferred Stock held by Horizon Technology Funding Company III LLC, and (v) any shares of Common Stock or other securities of the Company issued in connection with any stock split, stock
dividend, recapitalization or similar event relating to any of the foregoing; excluding in all cases, however, any Registrable Securities sold by a person in a transaction in which rights under this Section 3 are not assigned in
accordance with this Agreement or any Registrable Securities sold to the public or sold pursuant to Rule 144 promulgated under the Securities Act. 

  
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 (f) Registration. The terms “register,”
“registered,” and “registration” refer to a registration effected by preparing and filing a registration statement in compliance with the Securities Act, and the declaration or ordering of
effectiveness of such registration statement. 
 (g) Registration Expenses. “Registration
Expenses” shall mean all expenses incurred by the Company in complying with Sections 3.2, 3.3 and 3.5 hereof, including, without limitation, all registration and filing fees, printing expenses, fees and
disbursements of counsel and accountants for the Company, fees and expenses of one counsel for all the Holders, blue sky fees and expenses and the expense of any special audits incident to or required by any such registration (but excluding the
compensation of regular employees of the Company, which shall be paid in any event by the Company). 
 (h) SEC. The
term “SEC” or “Commission” means the U.S. Securities and Exchange Commission. 

(i) Selling Expenses. “Selling Expenses” shall mean all underwriting discounts and selling
commissions applicable to the sale of Registrable Securities. 
 3.2 Requested Registration. 

(a) Request for Registration by Initiating Holders. If the Company shall receive from an Initiating Holder, at any time,
a written request that the Company effect any registration with respect to all or a part of the Registrable Securities, the Company will: 

(i) promptly give written notice of the proposed registration, qualification or compliance to all other Holders of Registrable Securities;
and 
 (ii) as soon as practicable, use its best efforts to effect such registration (including, without limitation, the execution of an
undertaking to file post-effective amendments, appropriate qualification under applicable blue sky or other state securities laws and appropriate compliance with applicable regulations issued under the Securities Act) as may be so requested and as
would permit or facilitate the sale and distribution of all or such portion of such Registrable Securities as are specified in such request, together with all or such portion of the Registrable Securities of any Holder or Holders joining in such
request as are specified in a written request received by the Company within 15 days after written notice from the Company is given under Section 3.2(a)(i) above; provided, however, that the Company shall not be obligated
to effect, or take any action to effect, any such registration pursuant to this Section 3.2(a): 
 (A) In any particular
jurisdiction in which the Company would be required to execute a general consent to service of process in effecting such registration, qualification or compliance, unless the Company is already subject to service in such jurisdiction and except as
may be required by the Securities Act or applicable rules or regulations thereunder; 

  
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 (B) After the Company has effected a total of two (2) such registrations pursuant to
Section 3.2 and such registrations have been declared or ordered effective and the sales of such Registrable Securities shall have closed; or 

(C) If the Registrable Securities requested by all Holders to be registered pursuant to such request have an anticipated aggregate offering
price to the public of less than $10,000,000; or 
 (D) Prior to the earlier of the date that is three years after the date of this
Agreement and the date that is six months after the Company’s Initial Public Registration. 
 The registration statement filed pursuant
to the request of the Initiating Holders may, subject to the provisions of Section 3.2(b) below, include other securities of the Company which are held by officers or directors of the Company, or which are held by persons who, by virtue
of agreements with the Company, are entitled to include their securities in any such registration, but the Company and such other holders shall have no absolute right to include any of its securities in any such registration. 

(b) Underwriting; Request by Initiating Holders. If the Initiating Holders intend to distribute the Registrable
Securities covered by their request by means of an underwriting, they shall so advise the Company as a part of their request made pursuant to Section 3.2(a) and the Company shall include such information in the written notice referred to
in Section 3.2(a). In such event, the right of any Holder to include such Holder’s Registrable Securities in such registration shall be conditioned upon such Holder’s participation in such underwriting and the inclusion of such
Holder’s Registrable Securities in the underwriting (unless otherwise mutually agreed by a majority in interest of the Initiating Holders and such Holder) to the extent provided herein. All Holders proposing to distribute their securities
through such underwriting shall (together with the Company as provided in Section 3.6(e)) enter into an underwriting agreement in customary form with the underwriter or underwriters selected for such underwriting by a majority in
interest of the Initiating Holders and reasonably acceptable to the Company. Notwithstanding any other provision of Section 3.2, if the underwriter advises the Company and the Initiating Holders in writing that marketing factors require
a limitation of the number of shares to be underwritten, then the Company shall so advise all Holders of Registrable Securities which would otherwise be underwritten pursuant hereto, and the number of shares of Registrable Securities that may be
included in the underwriting shall be allocated among all Holders thereof, including the Initiating Holders, in such proportion (as nearly as practicable) among the Holders pro rata based on the amount of Registrable Securities owned by each
Holder; provided, however, that the number of shares of the Holders’ Registrable Securities to be included in such underwriting shall not be reduced until all other securities requested to be included in such underwriting have been excluded
entirely. 
 (c) Notwithstanding the foregoing, if the Company shall furnish to the Holders requesting the filing of a
registration statement pursuant to Section 3.2(a), a certificate signed by the President or Chief Executive Officer of the Company stating that 

  
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in the good faith judgment of the Board of Directors of the Company, it would be seriously detrimental to the Company and its stockholders for such registration statement to be filed and it is
therefore necessary to defer the filing of such registration statement, then the Company shall have the right to defer such filing for a period of not more than 120 days after receipt of the request of the Initiating Holders; provided,
however, that the Company may not utilize this right more than once in any twelve (12) month period. 
 3.3 Piggyback
Registrations. 
 (a) Notice. The Company shall notify all Holders of Registrable Securities in writing at
least 15 days prior to filing any registration statement under the Securities Act for purposes of effecting a public offering of securities of the Company (including, but not limited to, registration statements relating to secondary offerings of
securities of the Company, but excluding any registration statement relating to any employee benefit plan or a corporate reorganization) and will (subject to Section 3.3(b) hereof) afford each such Holder an opportunity to include in
such registration statement all or any part of the Registrable Securities then held by such Holder. Each Holder desiring to include in any such registration statement all or any part of the Registrable Securities held by such Holder shall, within 15
days after receipt of the above-described notice from the Company, so notify the Company in writing, and in such notice shall inform the Company of the number of Registrable Securities such Holder wishes to include in such registration statement. If
a Holder decides not to include all of its Registrable Securities in any registration statement thereafter filed by the Company, such Holder shall nevertheless continue to have the right to include any Registrable Securities in any subsequent
registration statement or registration statements as may be filed by the Company with respect to offerings of its securities, all upon the terms and conditions set forth herein. 

(b) Underwriting. If a registration statement under which the Company gives notice under Section 3.3 is for
an underwritten offering, then the Company shall so advise the Holders of Registrable Securities. In such event, the right of any such Holder’s Registrable Securities to be included in a registration pursuant to this Section 3.3
shall be conditioned upon such Holder’s participation in such underwriting and the inclusion of such Holder’s Registrable Securities in the underwriting to the extent provided herein. All Holders proposing to distribute their Registrable
Securities through such underwriting shall enter into an underwriting agreement in customary form with the managing underwriter or underwriter(s) selected for such underwriting. Notwithstanding any other provision of this Agreement, if the managing
underwriter(s) determine(s) in good faith that marketing factors require a limitation of the number of shares to be underwritten, then the managing underwriter(s) may exclude shares (including Registrable Securities) from the registration and the
underwriting, and the number of shares that may be included in the registration and the underwriting shall be allocated, first, to the Company, second, to each of the Holders of Registrable Securities requesting inclusion of their
Registrable Securities in such registration statement, to be allocated among all Holders thereof pro rata based on the amount of Registrable Securities of the Company owned by each Holder and third, to each of the other holders of the
Company’s securities, other than the Holders requesting inclusion of their Registrable Securities in 

  
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such registration statement, to be allocated among such other holders thereof pro rata based on the number of shares owned by each such other holder; provided, however, that
the right of the underwriters to exclude Registrable Securities from the registration and underwriting as described above shall be restricted so that the number of Registrable Securities included in any such registration is not reduced below
twenty-five percent (25%) of the shares included in the registration, except for a registration relating to the Company’s Initial Public Registration from which all Registrable Securities may be excluded. Any Registrable Securities
excluded or withdrawn from such underwriting shall be excluded and withdrawn from the registration. For any Holder which is a partnership or corporation, the partners, retired partners and stockholders of such Holder, or the estates and family
members of any such partners and retired partners and any trusts for the benefit of any of the foregoing persons shall be deemed to be a single “Holder,” and any pro rata reduction with respect to such
“Holder” shall be based upon the aggregate amount of shares carrying registration rights owned by all entities and individuals included in such “Holder,” as defined in this sentence. 

3.4 Expenses of Registration. All Registration Expenses incurred in connection with two demand registrations (pursuant to
Section 3.2), all piggyback registrations (pursuant to Section 3.3) and S-3 registrations (pursuant to Section 3.5) shall be borne by the Company, and all Selling Expenses shall be borne by the Holders of the
securities so registered pro rata on the basis of the number of their shares so registered. 
 3.5 Form S-3
Registration. In case the Company shall receive from one or more Holders a written request or requests that the Company effect a registration on Form S-3 and any related qualification or compliance with respect to all or a part of the
Registrable Securities owned by such Holders, provided the number of shares requested to be sold would have an aggregate price to the public of at least $1,000,000, then the Company will: 

(a) Notice. Promptly give written notice of the proposed registration and the Holder’s request therefor, and any
related qualification or compliance, to all other Holders of Registrable Securities; and 
 (b) Registration. As soon
as practicable, use its best efforts to effect such registration and all such qualifications and compliances as may be so requested and as would permit or facilitate the sale and distribution of all or such portion of the Holder’s Registrable
Securities as are specified in such request together with all or such portion of the Registrable Securities of any Holder or Holders joining in such request as are specified in a written request received by the Company within 15 days after written
notice from the Company is given under Section 3.5(a) above; provided, however, that the Company shall not be obligated to effect any such registration, qualification or compliance pursuant to this Section 3.5:

 (i) if Form S-3 is not available for such offering by the Holders; 

(ii) if the Company shall furnish to the Holders a certificate signed by the President or Chief Executive Officer of the Company stating that
in the good faith 

  
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judgment of the Board of Directors of the Company, it would be seriously detrimental to the Company and its stockholders for such Form S-3 Registration to be effected at such time, in which event
the Company shall have the right to defer the filing of the Form S-3 registration statement for an aggregate of not more than 120 days after receipt of the request of the Holders; provided, however, that the Company may not utilize this right more
than once in any twelve (12) month period; 
 (iii) if the Company has already effected two (2) such registrations on Form S-3
pursuant to this Section in any twelve-month period; or 
 (iv) in any particular jurisdiction in which the Company would be required to
qualify to do business or to execute a general consent to service of process in effecting such registration, qualification or compliance. 

Subject to the foregoing, the Company shall use its best efforts to file a Form S-3 registration statement covering the Registrable Securities
and other securities so requested to be registered pursuant to this Section 3.5 as soon as practicable after receipt of the request the Holders for such registration. 

3.6 Obligations of the Company. Whenever required to effect the registration of any Registrable Securities under this Agreement,
the Company shall, as expeditiously as reasonably possible: 
 (a) Prepare and file with the SEC a registration
statement with respect to such Registrable Securities and use its best efforts to cause such registration statement to become effective, and keep such registration statement effective until the distribution is completed, but not more than 180 days.

 (b) Prepare and file with the SEC such amendments and supplements to such registration statement and the prospectus used
in connection with such registration statement as may be necessary to comply with the provisions of the Securities Act with respect to the disposition of all securities covered by such registration statement. 

(c) Furnish to the Holders such number of copies of a prospectus, including a preliminary prospectus, in conformity with the
requirements of the Securities Act, and all amendments and supplements thereto, and such other documents as they may reasonably request in order to facilitate the disposition of the Registrable Securities owned by them that are included in such
registration. 
 (d) Use its best efforts to register and qualify the securities covered by such registration statement under
such other securities or Blue Sky laws of such jurisdictions as shall be reasonably requested by the Holders, provided, however, that the Company shall not be required in connection therewith or as a condition thereto to qualify to do
business or to file a general consent to service of process in any such states or jurisdictions. 
 (e) In the event of any
underwritten public offering, enter into and perform its obligations under an underwriting agreement, in usual and customary form, with the managing underwriter(s) of such offering. Each Holder participating in such underwriting shall also enter
into and perform its obligations under such an agreement. 

  
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 (f) Notify each Holder of Registrable Securities covered by such registration
statement at any time when a prospectus relating thereto is required to be delivered under the Securities Act of the happening of any event as a result of which the prospectus included in such registration statement, as then in effect, includes an
untrue statement of a material fact or omits to state a material fact required to be stated therein or necessary to make the statements therein not misleading in the light of the circumstances then existing and, following such notification, promptly
deliver to each Holder copies of all amendments or supplements referred to in paragraphs (b) and (c) of this Section 3.6. 

(g) Furnish, at the request of any Holder registering Registrable Securities, on the date that such Registrable Securities are
delivered to the underwriters for sale, if such securities are being sold through underwriters, (i) an opinion, dated as of such date, of the counsel representing the Company for the purposes of such registration, in form and substance as is
customarily given to underwriters in an underwritten public offering addressed to the underwriters, if any, and if there are no underwriters, to the Holders requesting registration of Registrable Securities and (ii) a “comfort” letter
dated as of such date, from the independent certified public accountants of the Company, in form and substance as is customarily given by independent certified public accountants to underwriters in an underwritten public offering and reasonably
satisfactory to a majority in interest of the Holders requesting registration, addressed to the underwriters. 
 3.7 Furnish
Information. It shall be a condition precedent to the obligations of the Company to take any action pursuant to Sections 3.2, 3.3 or 3.5 that the selling Holders shall furnish to the Company such information regarding
themselves, the Registrable Securities held by them, and the intended method of disposition of such securities as shall be required to timely effect the registration of Registrable Securities. 

3.8 Delay of Registration. No Holder shall have any right to obtain or seek an injunction restraining or otherwise delaying any
such registration as the result of any controversy that might arise with respect to the interpretation or implementation of this Section 3. 

3.9 Indemnification. In the event any Registrable Securities are included in a registration statement under Sections 3.2,
3.3 or 3.5: 
 (a) By the Company. To the extent permitted by law, the Company will indemnify and
hold harmless each Holder, the partners, members, officers and directors of each Holder, any grantor or beneficiary of each Holder that is a trust, any underwriter (as defined in the Securities Act) for such Holder and each person, if any, who
controls such Holder or underwriter within the meaning of the Securities Act or the Exchange Act against any losses, claims, damages, or liabilities (joint or several) to which they may become subject under the Securities Act, the Exchange Act or
other federal or state law, insofar as such losses, claims, damages, or liabilities (or actions in respect thereof) arise out of or are based upon any of the following statements, omissions or violations (collectively a
“Violation”): 
 (i) any untrue statement or alleged untrue statement of a material fact contained or incorporated
by reference in such registration statement, including any preliminary prospectus or final prospectus contained therein or any amendments or supplements thereto; 

  
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 (ii) the omission or alleged omission to state therein a material fact required to be stated
therein, or necessary to make the statements therein not misleading; or 
 (iii) any violation or alleged violation by the Company of the
Securities Act, the Exchange Act, any federal or state securities law or any rule or regulation promulgated under the Securities Act, the Exchange Act or any federal or state securities law in connection with the offering covered by such
registration statement; 
 and the Company will reimburse each such Holder, partner, member, officer or director, underwriter or controlling person for any
legal or other expenses reasonably incurred by them, as incurred, in connection with investigating or defending any such loss, claim, damage, liability or action; provided, however, that the indemnity agreement contained in this
subsection 3.9(a) shall not apply to amounts paid in settlement of any such loss, claim, damage, liability or action if such settlement is effected without the consent of the Company (which consent shall not be unreasonably withheld), nor
shall the Company be liable in any such case for any such loss, claim, damage, liability or action to the extent that it arises out of or is based upon a Violation which occurs in reliance upon and in conformity with written information furnished in
writing and expressly stated for use in connection with such registration by such Holder, partner, member, officer, director, underwriter or controlling person of such Holder. 

(b) By Selling Holders. To the extent permitted by law, each selling Holder will, if Registrable Securities held by such
Holder are included in the securities as to which such registration is being effected, indemnify and hold harmless the Company, each of its directors, each of its officers who have signed the registration statement, each person, if any, who controls
the Company within the meaning of the Securities Act, any underwriter (as defined in the Securities Act) and any other Holder selling securities under such registration statement or any of such other Holder’s partners, members, directors or
officers or any person who controls such underwriter or other Holder within the meaning of the Securities Act or the Exchange Act, against any losses, claims, damages or liabilities (joint or several) to which the Company or any such director,
officer, controlling person, underwriter or other such Holder, member, partner or director, officer or controlling person of such underwriter or other Holder may become subject under the Securities Act, the Exchange Act or other federal or state
law, insofar as such losses, claims, damages or liabilities (or actions in respect thereto) arise out of or are based upon any Violation, in each case to the extent (and only to the extent) that such Violation occurs in reliance upon and in
conformity with written information furnished by such Holder by an instrument duly executed by such Holder and stated to be specifically for use in such registration; and each such Holder will reimburse any legal or other expenses reasonably
incurred by the Company or any such director, officer, 

  
 - 12 - 

 
controlling person, underwriter or other Holder, partner, member, officer, director or controlling person of such other Holder or underwriter in connection with investigating or defending any
such loss, claim, damage, liability or action; provided, however, that the indemnity agreement contained in this subsection 3.9(b) shall not apply to amounts paid in settlement of any such loss, claim, damage, liability or
action if such settlement is effected without the consent of the Holder, which consent shall not be unreasonably withheld; and provided further, that the total amounts payable in indemnity by a Holder under this Section 3.9(b) in
respect of any Violation shall not exceed the lesser of (i) that proportion of the total of such losses, claims, damages, expenses, or liabilities indemnified against equal to the proportion of the total securities sold under such registration
statement which is being held by such Investor, or (ii) the amount equal to the net proceeds received by such Holder in the registered offering out of which such Violation arises. 

(c) Notice. Promptly after receipt by an indemnified party under Section 3.9 of notice of the commencement
of any action (including any governmental action), such indemnified party will, if a claim in respect thereof is to be made against any indemnifying party under Section 3.9, deliver to the indemnifying party a written notice of the
commencement thereof and the indemnifying party shall have the right to participate in, and, to the extent the indemnifying party so desires, jointly with any other indemnifying party similarly noticed, to assume the defense thereof with counsel
mutually satisfactory to the parties; provided, however, that an indemnified party shall have the right to retain its own counsel, with the fees and expenses to be paid by the indemnifying party, if representation of such indemnified
party by the counsel retained by the indemnifying party would be inappropriate due to actual or potential conflict of interests between such indemnified party and any other party represented by such counsel in such proceeding. The failure to deliver
written notice to the indemnifying party within a reasonable time of the commencement of any such action, if materially prejudicial to its ability to defend such action, shall relieve such indemnifying party of any liability to the indemnified party
under Section 3.9, but the omission so to deliver written notice to the indemnifying party will not relieve it of any liability that it may have to any indemnified party otherwise than under Section 3.9. 

(d) Survival. The obligations of the Company and Holders under Section 3.9 shall survive the completion of
any offering of Registrable Securities in a registration statement, and otherwise. 
 3.10 “Market Stand-Off”
Agreement. Each Holder hereby agrees that it shall not, to the extent requested by the Company or an underwriter of securities of the Company, sell or otherwise transfer or dispose of any Registrable Securities or other shares of stock of
the Company then owned by such Holder (other than to donees, members or partners of the Holder who agree to be similarly bound) for up to 180 days following the date of the final prospectus filed in connection with a registration statement of the
Company filed under the Securities Act; provided, however, that such agreement shall be applicable only to the first such registration statement of the Company that covers securities to be sold on its behalf to the public in an underwritten offering
(but not to Registrable Securities sold pursuant to such registration statement) and provided, further, that each officer and director of the Company and each 3% or  

  
 - 13 - 

 
greater stockholders of the Company also agrees to such restrictions. In addition, each Holder agrees to execute any agreement reflecting the foregoing as may be requested by the Company or such
underwriters at the time of the underwritten offering. Each Holder agrees to be similarly bound for up to 90 days following the date of the final prospectus filed in connection with any “follow-on” public offering of the Company’s
securities taking place within one year of the effective date of the Company’s initial public offering. 
 The provisions of this
Section 3.10 shall be binding upon any transferee or assignee of any Registrable Securities, whether or not such persons are entitled to registration rights pursuant to Section 3.13. 

3.11 Limitations on Subsequent Registration Rights. From and after the date of this Agreement, the Company shall not, without
the prior written consent of the Holders of at least 50% of the Registrable Securities, which amount shall include the holders of at least a majority of the Series B-1 Preferred Stock, grant any registration rights superior to registration rights of
the Holders. 
 3.12 Rule 144 Reporting. With a view to making available the benefits of certain rules and regulations
of the Commission which may at any time permit the sale of the Registrable Securities to the public without registration, after such time as a public market exists for the Common Stock of the Company, the Company agrees to: 

(a) Make and keep public information available, as those terms are understood and defined in Rule 144 under the Securities Act,
at all times after the effective date of the first registration under the Securities Act filed by the Company for an offering of its securities to the general public; 

(b) Use its best efforts to file with the Commission in a timely manner all reports and other documents required of the Company
under the Securities Act and the Exchange Act (at any time after it has become subject to such reporting requirements); and 

(c) So long as a Holder owns any Registrable Securities, to furnish to the Holder forthwith upon request a written statement by
the Company as to its compliance with the reporting requirements of Rule 144 (at any time after 90 days after the effective date of the first registration statement filed by the Company for an offering of its securities to the general public), and
of the Securities Act and the Exchange Act (at any time after it has become subject to the reporting requirements of the Exchange Act), a copy of the most recent annual or quarterly report of the Company, and such other reports and documents of the
Company as a Holder may reasonably request in availing itself of any rule or regulation of the Commission allowing a Holder to sell any such securities without registration (at any time after the Company has become subject to the reporting
requirements of the Exchange Act). 
 3.13 Assignment of Registration Rights. The rights of a Holder under this
Section 3 may be assigned by any Holder in connection with any transfer or assignment by a Holder of Registrable Securities provided that: (i) such transfer may otherwise be effected in 

  
 - 14 - 

 
accordance with applicable securities laws, (ii) such transfer is effected in compliance with the restrictions on transfer contained in the Agreement and in any other agreement between the
Company and the Holder, (iii) such assignee or transferee either holds subsequent to such transfer not less than 1,000,000 shares of Registrable Securities or is a subsidiary, wholly-owned entity, successor entity, parent, affiliate, member or
stockholder of a Holder, and (iv) such other party agrees in writing with the Company to be bound by all of the provisions of this Section 3. 

3.14 Termination of Registration Rights. The registration rights granted pursuant to this Section 3 will terminate
as to any Holder upon the earlier to occur of (a) the three-year anniversary following the effective date of the Company’s Initial Public Registration or (b) such time as in the opinion of counsel to the Company a Holder can sell all
of its remaining Registrable Securities under Rule 144 during any three (3)-month period. 
 4. RIGHT OF FIRST OFFER TO SUBSCRIBE
TO NEW ISSUANCES. 
 4.1 General. The Company hereby grants to each Investor the right of
first offer to purchase such Investor’s pro rata share (“Pro Rata Share”) of New Securities (as defined in Section 4.2(a)) that the Company may, from time to time, propose to sell and issue. Such
Investor’s Pro Rata Share, for purposes of this right of first offer, is the ratio that the number of shares of Common Stock (assuming conversion of all Preferred Stock and securities convertible into Common Stock but not including options or
warrants to acquire Common Stock) held by such Investor bears to the total number of shares of Common Stock outstanding immediately prior to the time of issuance of such New Securities (assuming conversion into Common Stock of all outstanding
Preferred Stock and any other securities convertible into Common Stock but not including options or warrants to acquire Common Stock). An Investor shall be entitled to apportion the right of first offer hereby granted it among itself and its
partners and affiliates, immediate family members or trusts for any of the foregoing in such proportions as it deems appropriate. This right of first offer shall be subject to the following provisions: 

4.2 Certain Definitions. For the purposes of Section 4: 

(a) “New Securities” shall mean any Common Stock or any Preferred Stock of the Company, whether or not
now authorized, and any rights, options, or warrants to purchase said Common Stock or Preferred Stock, and securities of any type whatsoever that are, or may become, convertible into or exchangeable for Common Stock or Preferred Stock;
provided, however, that “New Securities” does not include (i) shares of the Company’s Common Stock issued upon conversion of or with respect to the Preferred Stock or upon exercise or conversion of any
securities of the Company already outstanding as of the date on which the first share of Series B-1 was issued; (ii) securities offered to the public pursuant to the Company’s Initial Public Registration; (iii) shares issued pursuant
to the acquisition of another unaffiliated corporation by the Company by merger, purchase of substantially all of the assets, or other reorganization, in each case approved by the Board of Directors of the Company (including at least one director
designated by the holders of the Series B-1 Preferred Stock), whereby the Company owns not less than 50% of the voting power of the surviving corporation; (iv) shares of the Company’s Common Stock (or related options or warrants) issued to
employees, officers, directors, consultants, or other persons performing services for the Company (including, 

  
 - 15 - 

 
but not by way of limitation, distributors and sales representatives) pursuant to any stock offering, plan, or arrangement approved by the Board of Directors of the Company (including at least
one director designated by the holders of the Series B-1 Preferred Stock and at least one director designee of the holders of the Series A-1 Preferred Stock); (v) shares of Common Stock issued to equipment and property lessors, banks,
financial institutions and executive search firms in connection with transactions the principal purpose of which is other than the raising of equity capital, in each case as approved by the Board (including each of the Board designees of the Series
B-1 Preferred Stock and at least one director designee of the holders of the Series A-1 Preferred Stock); (vi) any other securities issued as to which the Company receives a written consent from the holders of a majority of the outstanding
Preferred Stock, which majority shall include the holders of at least a majority of the Series B-1 Preferred Stock, specifically excluding such securities from the ambit of Section 4.1 hereof; or (vii) shares of the Company’s
Common Stock issued as a dividend or distribution on Preferred Stock or any event for which adjustment is made pursuant to Section 5(f) or 5(g) of the Company’s Amended and Restated Certificate of Incorporation. 

4.3 Mechanics of Right. 

(a) Notices; Pro Rata Rights. In the event that the Company proposes to issue New Securities, it shall give each such
Investor written notice (the “First Notice”) of its intention, describing the type of New Securities, the price, and the general terms upon which the Company proposes to issue the same. Within 15 days after receipt of the
First Notice, each Investor shall give the Company written notice (the “Investor Notice”) of its intention to purchase or obtain, at the price and on the terms specified in the Notice, a number of shares equal to or less than
its Pro Rata Share of the New Securities. The Company shall promptly give written notice to each Investor that purchases its Pro Rata Share of the New Securities (a “Fully-Exercising Investor”) of the amount of New
Securities, if any, that other Investors do not elect to purchase in response to the First Notice (the “Second Notice”). Each Fully-Exercising Investor shall notify the Company within 15 days of receipt of the Second Notice
if it would like to purchase any of the unsubscribed shares and indicate the maximum number of unsubscribed shares it would like to purchase. The Company shall inform the Fully-Exercising Investor of the total number of unsubscribed shares available
and provide the Fully-Exercising Investor with an allocation of the unsubscribed shares available to each Fully-Exercising Investor. The allocation of unsubscribed shares for each Fully-Exercising Investor shall be determined by aggregating the
number of shares equal to the Pro Rata Share of New Securities of all non-subscribing Investors, and multiplying such aggregate number of shares by a fraction, the numerator of which shall be the number of shares of Common Stock (assuming conversion
of all Preferred Stock and securities convertible into Common Stock but not including options or warrants to acquire Common Stock) held by such Fully-Exercising Investor, and the denominator of which shall be the aggregate number of shares of Common
Stock (assuming conversion of all Preferred Stock and securities convertible into Common Stock but not including options or warrants to acquire Common Stock) held by all Fully-Exercising Investors. 

  
 - 16 - 

 (b) Company Right. To the extent that the Investors fail to exercise in
full the right of first offer as provided in Section 4.3(a) hereof, the Company shall have 90 days thereafter to sell (or enter into an agreement pursuant to which the sale of New Securities covered thereby shall be closed, if at all,
within said 90-day period) the New Securities respecting which the Investors’ rights were not exercised, at a price and upon general terms no more favorable to the purchasers thereof than specified in the First Notice. In the event the Company
has not sold the New Securities within said 90-day period (or sold and issued New Securities in accordance with the foregoing within 90 days from the date of said agreement), the Company shall not thereafter issue or sell any New Securities, without
first offering such securities to the Investors in the manner provided above. 
 (c) No Impairment. An Investor’s
failure to exercise this right of first offer on any issuance of New Securities shall not adversely affect the Investor’s right of first offer to purchase subsequent issuances of New Securities. 

4.4 Termination. The rights of first offer under this Section 4 shall not apply to and shall terminate upon the
closing of the Company’s Initial Public Registration. 
 4.5 Assignment. The rights of first offer under this
Section 4 may be assigned by any Holder in connection with any transfer or assignment by a Holder of Registrable Securities provided that: (i) such transfer may otherwise be effected in accordance with applicable securities laws,
(ii) such transfer is effected in compliance with the restrictions on transfer contained in the Agreement and in any other agreement between the Company and the Holder, (iii) such assignee or transferee either holds subsequent to such
transfer not less than 1,000,000 shares of Registrable Securities (as adjusted for combinations, stock dividends, subdivisions or split-ups) or is a subsidiary, wholly-owned entity, successor entity, parent, affiliate, member or stockholder of a
Holder, or a grantor or beneficiary of a Holder that is a trust, and (iv) such other party agrees in writing with the Company to be bound by all of the provisions of this Section 4. Any Holder may transfer the right of first offer
under this Section 4 to an affiliate without requirement of any concurrent transfer of Registrable Securities, provided that such affiliate agrees in writing with the Company to be bound by all obligations of this Agreement to which the
transferor is subject. 
 5. LEGENDS. 

Each Investor acknowledges that the Company may include the following legends (in addition to any legends required under applicable state
securities laws) on each share certificate evidencing any Registrable Securities: 
 (a) “THESE SECURITIES HAVE NOT BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933 OR ANY APPLICABLE STATE’S SECURITIES LAW. THEY MAY NOT BE SOLD, OFFERED FOR SALE, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT AS TO THE SECURITIES UNDER SUCH ACT AND
LAWS OR AN OPINION OF COUNSEL SATISFACTORY TO THE CORPORATION THAT SUCH REGISTRATION IS NOT REQUIRED.” 

  
 - 17 - 

 (b) “THE SALE, TRANSFER OR ASSIGNMENT OF THE SECURITIES REPRESENTED BY THIS
CERTIFICATE ARE SUBJECT TO THE TERMS OF AN AGREEMENT BETWEEN THE COMPANY AND THE REGISTERED HOLDER OR HIS PREDECESSOR IN INTEREST. COPIES OF SUCH AGREEMENT MAY BE OBTAINED BY WRITTEN REQUEST MADE BY THE HOLDER OF RECORD OF THIS CERTIFICATE TO THE
SECRETARY OF THE COMPANY.” 
 (c) Any legend required to be place thereon by any other applicable state securities laws.

 6. MISCELLANEOUS. 

6.1 Successors and Assigns. Except as otherwise expressly provided herein, the terms and conditions of this Agreement shall
inure to the benefit of and be binding upon the respective successors and permitted transferees and permitted assigns of the parties. 

6.2 Governing Law. This Agreement shall be governed in all respects by the laws of the State of Delaware as applied to contracts
made and to be performed entirely within that state between residents of that state. 
 6.3 Counterparts. This
Agreement may be executed in any number of counterparts, each of which shall be deemed an original, and all of which together shall constitute one instrument. Facsimile copies of executed signature pages hereto shall be deemed binding originals
hereunder. 
 6.4 Titles and Subtitles. The titles of the paragraphs and subparagraphs of this Agreement are used for
convenience only and are not to be considered in construing or interpreting this Agreement. 
 6.5 Stock Splits, etc.
All share numbers used in this Agreement are subject to adjustment in the case of any stock split, reverse stock split, combination or similar events. 

6.6 Notices. Any notice required or permitted to be given to a party pursuant to the provisions of this Agreement will be in
writing and will be effective on (i) the date of delivery by facsimile, or (ii) the business day after deposit with a nationally-recognized courier or overnight service, including Express Mail, for United States deliveries or
(iii) five (5) business days after deposit in the United States mail by registered or certified mail for United States deliveries. All notices not delivered personally or by facsimile will be sent with postage and other charges prepaid and
properly addressed to the party to be notified at the address set forth below such party’s signature on this Agreement or at such other address as such party may designate by ten (10) days advance written notice to the other parties
hereto. Notwithstanding the foregoing, all notices for delivery outside the United States shall be sent by facsimile (in which case said notice shall be deemed effective as of the next business day following the date of transmission) or nationally
recognized courier (in which case said notice shall be deemed effective as of the fifth day following the date of mailing). Any notice given hereunder to more than one person will be deemed to have been given, for purposes of counting time periods
hereunder, on the date given to the last party required to be given such notice. Notices to the Company will be marked to the attention of the Chief Executive Officer. 

  
 - 18 - 

 6.7 Attorneys’ Fees. If any action at law or in equity is necessary to enforce
or interpret the terms of this Agreement, the prevailing party shall be entitled to reasonable attorneys’ fees, costs and necessary disbursements in addition to any other relief to which such party may be entitled. 

6.8 Amendments and Waivers. Any term of this Agreement may be amended and the observance of any term of this Agreement may be
waived (either generally or in a particular instance and either retroactively or prospectively), only with the written consent of the party against whom enforcement of such amendment or waiver is sought; provided, however that with respect to any
Investor, the consent of the holders of more than 50% of the Registrable Securities shall be sufficient to bind any and all Investors, which percentage must include the holders of at least a majority of the Series B-1 Preferred Stock. 

6.9 Severability. If any provision of this Agreement is held to be unenforceable under applicable law, then such provision shall
be excluded from this Agreement and the balance of the Agreement shall be interpreted as if such provision was so excluded and shall be enforceable in accordance with its terms. 

6.10 Entire Agreement. This Agreement constitutes the full and entire understanding and agreement between the parties with
respect to the subject matter hereof, and supersedes all prior negotiations, correspondence, agreements, understandings, duties or obligations among the parties with respect to the subject matter hereof. 

6.11 Further Assurances. From and after the date of this Agreement, upon the request of a party, the other parties shall execute
and deliver such instruments, documents or other writings as may be reasonably necessary or desirable to confirm and carry out and to effectuate fully the intent and purposes of this Agreement. 

6.12 Waiver of Preemptive Rights. For good and valuable consideration, the receipt of which is hereby acknowledged, each
Investor who is a party to the Prior Agreement hereby waives, solely with respect to the sales of Preferred Stock by the Company to the Investors pursuant to the Purchase Agreement, any and all preemptive rights and associated rights of notice
accruing to such Investor pursuant to Section 4 of the Prior Agreement, and further acknowledges that the execution of this Agreement by the holders of more than 50% of the Registrable Securities (as defined in the Prior Agreement) shall
act as a valid waiver of such rights on behalf of all such Investors pursuant to Section 6.8 of the Prior Agreement. 

6.13 Aggregation of Shares. The Registrable Securities held by any affiliated entities or persons of an Investor shall be
aggregated with such Investor’s Registrable Securities solely for purposes of determining whether or not any right granted hereunder is applicable to such Investor. 

6.14 Termination of Prior Agreement. The Prior Agreement is hereby amended and restated in its entirety and shall be of no
further force or effect. 

  
 - 19 - 

 6.15 Trustee Liability. With respect to its signatory capacity and liability as the
trustee of The Wellcome Trust, The Wellcome Trust Limited (the “Trustee”), enters into this Agreement in its capacity as the trustee for the time being of The Wellcome Trust but not otherwise and it is hereby
agreed and declared that notwithstanding anything to the contrary contained or implied in this Agreement: 
 (a) the
obligations incurred by the Trustee under or in consequent of this Agreement shall be enforceable against it or the other trustees of The Wellcome Trust from time to time; and 

(b) the liabilities of the Trustee (or such other trustees as are referred to in paragraph (a) above) in respect of such
obligations shall be limited to such liabilities as can, and may lawfully and properly be met out of the assets of The Wellcome Trust for the time being in the hands or under the control of the Trustee or such other trustees. 

[Remainder of Page Intentionally Left Blank] 

  
 - 20 - 

 IN WITNESS WHEREOF, the parties hereto have executed this Amended and Restated Investor
Rights Agreement as of the date first above written. 
  

			
	COMPANY:
	
	XTERA COMMUNICATIONS, INC.
		
	By:	 	 /s/ Jon R. Hopper

		 	Jon R. Hopper
		 	President and Chief Executive Officer

 
			
		
	Address:	 	500 W. Bethany Drive,
		 	Suite 100 Allen, TX 75013

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	
	 THE WELLCOME TRUST LIMITED,

AS TRUSTEE OF THE WELLCOME TRUST

		
	By:	 	 /s/ S Robertson

	Name:	 	 Sandra Robertson

	Title:	 	 Co-Head of Portfolio Management

			
	Address:	 	215 Euston Road,
		 	London NW1 2BE,
		 	United Kingdom

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	
	NEW ENTERPRISE ASSOCIATES 10, L.P.
		
	By:	 	NEA Partners 10, L.P.
		 	Its General Partner
		
	By:	 	 /s/ C. Richard Kramlich

	Name:	 	 C. Richard Kramlich

	Title:	 	 General Partner

 
			
	Address:	 	1119 St. Paul St.
		 	Baltimore, MD 21202

 
			
	
	NEW ENTERPRISE ASSOCIATES 9, L.P.
		
	By:	 	NEA Partners 9, L.P.
		 	Its General Partner
		
	By:	 	 /s/ C. Richard Kramlich

	Name:	 	 C. Richard Kramlich

	Title:	 	 General Partner

 
			
	Address:	 	1119 St. Paul St.
		 	Baltimore, MD 21202

 
			
	
	NEA VENTURES 2000, L.P.
		
	By:	 	 /s/ Cindy Crnkovich

	Name:	 	 Cindy Crnkovich

	Title:	 	 Vice President

 
			
	Address:	 	1119 St. Paul St.
		 	Baltimore, MD 21202

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	
	ARCH VENTURE FUND III, L.P.
		
	By:	 	ARCH Venture Partners, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND IV, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND IV A, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH ENTREPRENEURS FUND, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND VI, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	
	SEVIN ROSEN FUND VII L.P.
		
	By:	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner

 
			
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240

 
			
	
	SEVIN ROSEN VII AFFILIATES FUND L.P.
		
	By	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner

 
			
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240

 
			
	
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	Vice President

 
			
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	
	COMMUNICATIONS VENTURES IV, L.P.
	By:	 	ComVen IV, L.L.C
		 	Its General Partner
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	VP and General Counsel

 
			
		
	Address:	 	305 Lytton Avenue
		 	Palo Alto. CA 94301

 
			
	
	COMMUNICATIONS VENTURES IV CEO FUND, L.P.
	By:	 	ComVen IV, L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	VP and General Counsel

 
			
		
	Address:	 	305 Lytton Avenue
		 	Palo Alto, CA 94301

 
			
	
	COMMUNICATION VENTURES IV ENTREPRENEURS’ FUND, L.P.
	By:	 	ComVen IV, L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	VP and General Counsel

 
			
		
	Address:	 	305 Lytton Avenue
		 	Palo Alto, CA94301

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	
	UC BERKELEY FOUNDATION
		
	By:	 	 /s/ Patrick O’Leary

	Name:	 	Patrick O’Leary
	Title:	 	Vice President

 
			
		
	Address:	 	2080 Addison, Suite 4200
		 	Berkeley, CA 94720

 
			
		
	By:	 	 /s/ Loraine Binion

	Name:	 	Loraine Binion
	Title:	 	Interim Treasurer

 
			
		
	Address:	 	2080 Addison, Suite 4200
		 	Berkeley, CA 94720

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	SERIES A-l STOCKHOLDERS:
	
	INTERWEST INVESTORS Q, VIII, LP
		
	By:	 	 /s/ Arnold L. Oronsky

	Name:	 	 Arnold L. Oronsky

	Title:	 	 Managing Director

 

			
		
	Address:	 	  

	  

			
	
	INTERWEST INVESTORS VII, LP
		
	By:	 	 /s/ Arnold L. Oronsky

	Name:	 	 Arnold L. Oronsky

	Title:	 	 Managing Director

 

			
		
	Address:	 	  

	  

			
	
	INTERWEST INVESTORS VIII, LP
		
	By:	 	 /s/ Arnold L. Oronsky

	Name:	 	 Arnold L. Oronsky

	Title:	 	 Managing Director

 

			
		
	Address:	 	  

	  

			
	
	INTERWEST PARTNERS VII, LP
		
	By:	 	 /s/ Arnold L. Oronsky

	Name:	 	 Arnold L. Oronsky

	Title:	 	 Managing Director

 

			
		
	Address:	 	  

	  

			
	
	INTERWEST PARTNERS VIII, LP
		
	By:	 	 /s/ Arnold L. Oronsky

	Name:	 	 Arnold L. Oronsky

	Title:	 	 Managing Director

 

			
		
	Address:	 	  

	  

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	
	HAYDEN H. HARRIS LIVING TRUST DTD 3-6-98
		
	By:	 	 /s/ Hayden Harris

	Name:	 	Hayden Harris
	Title:	 	Trustee

 
			
		
	Address:	 	
		 	

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

							
	[signature block for entities]:	 		 	 LONDON PACIFIC ASSURANCE LIMITED

		 		 		 	(print name of entity)
				
		 		 	By:	 	 /s/ Robert A. Cornman

		 		 	Name:	 	 Robert A. Cornman

		 		 	Title:	 	 Director

			
	[signature block for individuals]:	 		 	  

		 		 		 	(signature)

							
				
		 		 	Print Name:	 	  

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

							
	[signature block for entities]:	 		 	  

		 		 		 	(print name of entity)
				
		 		 	By:	 	  

		 		 	Name:	 	  

		 		 	Title:	 	  

			
	[signature block for individuals]:	 		 	 /s/ JR Adox

		 		 		 	(signature)

							
				
		 		 	Print Name:	 	 James R. Adox

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	
	CURRENT VENTURES II LIMITED
		
	By:	 	 /s/ Peter T. Mok

	Name:	 	Peter T. Mok
	Title:	 	Managing General Partner

 
			
		
	Address:	 	225 Santa Clara Street, Suite 968
		 	San Jose, CA 95113

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	
	CLIFFORD HIGGERSON
	
	 /s/ Clifford H. Higgerson

			
		
	Address:	 	  

	  

	  

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

							
	[signature block for entities]:	 		 	  

		 		 		 	(print name of entity)
				
		 		 	By:	 	  

		 		 	Name:	 	  

		 		 	Title:	 	  

			
	[signature block for individuals]:	 		 	 /s/ Patrick Ennis

		 		 		 	(signature)

							
				
		 		 	Print Name:	 	 Patrick Ennis

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
					
	INVESTORS:
	
	EDF VENTURES I, LIMITED PARTNERSHIP
		
	By:	 	Enterprise Ventures, Limited Partnership,
		 	Its General Partner
		
	By:	 	EDM, Inc.,
		 	Its General Partner
			
		 	By:	 	 /s/ Beau D. Laskey

		 		 	Beau D. Laskey
		 		 	Vice President and Secretary

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	
	THE INFRASTRUCTURE FUND, LP
		
	By:	 	IF MANAGEMENT COMPANY, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Peter Hankin

	Name:	 	Peter Hankin
	Title:	 	Managing Member

 
			
		
	Address:	 	2710 Sand Hill Road
		 	Building 3, Suite 255
		 	Menlo Park, CA 94025

 
			
	
	THE INFRASTRUCTURE CO-INVEST FUND, LP
		
	By:	 	IF MANAGEMENT COMPANY, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Peter Hankin

	Name:	 	Peter Hankin
	Title:	 	Managing Member

 
			
		
	Address:	 	2710 Sand Hill Road
		 	Building 3, Suite 255
		 	Menlo Park, CA 94025

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	
	THOMAS S. PORTER RESTATED
	TRUST DTD. 11-14-05
		
	By:	 	 /s/ Thomas S. Porter

	Name:	 	Thomas S. Porter
	Title:	 	Trustee

 
			
		
	Address:	 	200 Orchard Hills Dr.
		 	Ann Arbor, MI 48104

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

							
	[signature block for entities]:	 		 	  

		 		 		 	(print name of entity)
				
		 		 	By:	 	  

		 		 	Name:	 	  

		 		 	Title:	 	  

			
		 		 	
	[signature block for individuals]:	 		 	 /s/ John Teegen

		 		 		 	(signature)

							
				
		 		 	Print Name:	 	 John Teegen

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

							
	[signature block for entities]:	 		 	 NORTHGATE PARTNERS,

		 		 	 a Delaware Multiple Series LLC

		 		 		 	(print name of entity)
				
		 		 	By:	 	 /s/ Mark Harris

		 		 	Name:	 	 Mark Harris

		 		 	Title:	 	 Managing Manager

			
	[signature block for individuals]:	 		 	  

		 		 		 	(signature)

							
				
		 		 	Print Name:	 	  

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	INVESTORS:
	STAR GROWTH ENTERPRISE, A GERMAN CIVIL LAW PARTNERSHIP (WITH LIMITATION OF LIABILITY)
	By: SVM Star Ventures Managementgesellschaft mbH Nr. 3
	Title: Managing Partner
		
	By:	 	 /s/ Meir Barel

	Name:	 	Dr. Meir Barel
	Title:	 	Managing Director

 
			
	Address:	 	Possartstrasse 9
		 	D-81679 Munich, Germany
	Fax No.:	 	+49-89-419-43030
	Attn:	 	Andreas Hofbauer

 
			
	
	SVE STAR VENTURES ENTERPRISES GMB & CO. NO. IX KG
	By: SVM Star Ventures Managementgesellschaft mbH Nr. 3
	Title: Managing Partner
		
	By:	 	 /s/ Meir Barel

	Name:	 	Dr. Meir Barel
	Title:	 	Managing Director

 
			
	Address:	 	Possartstrasse 9
		 	D-81679 Munich, Germany
	Fax No.:	 	+49-89-419-43030
	Attn:	 	Andreas Hofbauer

 
			
	
	STAR MANAGEMENT OF INVESTMENTS NO.II (2000) L.P.
	By: SVM Star Venture Capital Management Ltd.
		
	By:	 	 /s/ Meir Barel

	Name:	 	Dr. Meir Barel
	Title:	 	Director

 
			
	Address:	 	11 Galgaley Haplada Street
		 	Herzelia Pituach 46733, Israel
	Fax No.:	 	+972-9-9617111
	Attn:	 	Tami Gilboa-Arbel

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 
			
	SVM STAR VENTURES
	MANAGEMENTGESELLSCHAFT MBH NR. 3
		
	By:	 	 /s/ Meir Barel

	Name:	 	Dr. Meir Barel
	Title:	 	Managing Director

 
			
	Address:	 	Possartstrasse 9
		 	D-81679 Munich, Germany
	Fax No.:	 	+49-89-419-43030
	Attn:	 	Andreas Hofbauer

 
			
	
	SVM STAR VENTURES
	MANAGEMENTGESELLSCHAFT MBH NR. 3 & CO. BETEILIGUNGS KG NR. 3
	By: SVM Star Ventures Managementgesellschaft mbH Nr. 3
	Title: Managing Partner
		
	By:	 	 /s/ Meir Barel

	Name:	 	Dr. Meir Barel
	Title:	 	Managing Director

 
			
	Address:	 	Possartstrasse 9
		 	D-81679 Munich, Germany
	Fax No.:	 	+49-89-419-43030
	Attn:	 	Andreas Hofbauer

  
 [SECOND AMENDED
AND RESTATED INVESTORS’ RIGHTS AGREEMENT] 

 EXHIBIT A 

INVESTORS 
 Common Stockholders

 Aether Partners L.P. 

ARCH Entrepreneurs Fund, L.P. 

ARCH Venture Fund III LP 
 ARCH
Venture Fund IV LP 
 Jon Bayless 

Centerpoint Venture Fund III (Q), L.P. 

Centerpoint Venture Fund III, L.P. 

Comventures IV CEO Fund L.P. 

ComVentures IV Entr. Fund L.P. 

ComVentures IV L.P. 
 EDF Ventures
L.P. 
 Patrick Ennis 

Enterprise Dev. Fund II LP 

Deitrich Erdmann 
 Hook
Communications Partners LP 
 Hook Partners V LP 

Infrastructure Co-Invest Fund LP 

Infrastructure Fund L.P. 
 Mohr
Seed Capital II LP 
 New Enterprise Associates 10 L.P. 

New Enterprise Associates 9 L.P. 

Rho Management Trust I 
 Rho
Ventures IV (QP) L.P. 
 Rho Ventures IV GmbH & CO. Beteiligungs KG 

Rho Ventures IV L.P. 
 Sevin Rosen
Fund VII L.P. 
 Sevin Rosen VII Affiliates Fund L.P. 

Star Growth Enterprise, a German Civil Law Partnership (with limitation of liability) 

Star Management of Investments No. II (2000) L.P. 

Star Ventures Managementgesellschaft mbH Nr. 3 & Co. Beteiligungs KG Nr. 3 

SVE Star Ventures Enterprises GmbH & Co. No. IX KG 

SVM Star Ventures Managementgesellschaft mbH Nr. 3 

Thomas A. Kelley & Associates Profit Sharing Plan 

Trellis Partners II L.P. 
 UNC
Investment Fund LLC 
 University of California Berkeley Foundation 

University of Illinois Foundation 

University Technology Investors 

WS Investment 99B 

  
 1 

 Series A-l Investors 

Access Technology Partners 
 James
Adox 
 Aether Partners L.P. 

Aaron Alter 

Americanbuoy & Co. 
 ARCH
Entrepreneurs Fund, L.P. 
 ARCH Venture Fund III LP 

ARCH Venture Fund IV LP 
 ARCH
Venture Fund IVA L.P. 
 ARCH Venture Fund VI, L.P. 

Jon Bayless 
 Anand Bellary 

Donald Don Brooks 
 Thomas Brooks

 Centerpoint Venture Fund III (Q), L.P. 

Centerpoint Venture Fund III, L.P. 

Comventures IV CEO Fund L.P. 

ComVentures IV Entr. Fund L.P. 

ComVentures IV L.P. 

Cronus & Co. 
 Current
Ventures II L.P. 
 Dow Chemical Company 

Drutan Investments Ltd. 
 EDF
Ventures L.P. 
 Patrick Ennis 

Enspire Capital Limited 

Enterprise Dev. Fund II LP 

Deitrich Erdmann 
 Fullpath
Nominess Limited 
 Hambrecht & Quist California 

Hayden H. Harris Living Trust DTD 3-6-98 

Clifford Higgerson 
 Hook
Communications Partners LP 
 Hook Partners V LP 

Infrastructure Co-Invest Fund LP 

Infrastructure Fund L.P. 

InterWest Investors Q VIII 

InterWest Investors VII 

InterWest Investors VIII 

InterWest Partners VII 
 InterWest
Partners VIII 
 Anthony Jeffries 

JP Morgan Partners (BHCA) 
 Judith
A. Thompson Living Trust UTA March 12 1998 
 Kummell Investments Limited 

  
 2 

 Beau Laskey 

Mary L. Campbell Trust 
 Mohr Seed
Capital II LP 
 New Enterprise Associates 9 L.P. 

New Enterprise Associates 10 L.P. 

Northgate Partners, a Delaware Multiple Series LLC 

Rahn Group 
 Ram Rao 

Sena Reddy 
 Rell Family Partners
Limited 
 Rho Management Trust I 

Rho Ventures IV (QP) L.P. 
 Rho
Ventures IV GmbH & CO. Beteiligungs KG 
 Rho Ventures IV L.P. 

Dave Segre 
 Sevin Rosen Fund VII
L.P. 
 Sevin Rosen VII Affiliates Fund L.P. 

Sam Srinivasan 
 Star Growth
Enterprise, a German Civil Law Partnership (with limitation of liability) 
 Star Management of Investments No. II (2000) L.P. 

Star Ventures Managementgesellschaft mbH Nr. 3 & Co. Beteiligungs KG Nr. 3 

Sunny Century LLP 
 SVE Star
Ventures Enterprises GmbH & Co. No. IX KG 
 SVM Star Ventures Managementgesellschaft mbH Nr. 3 

John Teegen 
 Thomas A.
Kelley & Associates Profit Sharing Plan 
 Thomas S. Porter Restated Trust dated 7-31-98 

Tose Holdings Limited 
 Trellis
Partners II L.P. 
 UNC Investment Fund LLC 

University of California Berkeley Foundation 

University of Illinois Foundation 

University Technology Investors 

Isaac Vaughn 
 WS Investment 99B

 Series B-l Investors 
 The Wellcome
Trust Limited, as Trustee of The Wellcome Trust 
 New Enterprise Associates 10, L.P. 

New Enterprise Associates 9, L.P. 

ARCH Venture Fund III, L.P. 
 ARCH
Venture Fund IV, L.P. 
 ARCH Venture Fund IVA, L.P. 

ARCH Entrepreneurs Fund, L.P. 

ARCH Venture Fund VI, L.P. 
 Beau
D. Laskey 

  
 3 

 Clifford Higgerson 

Hayden H. Harris Living Trust DTD 3-6-98 

James R. Adox 
 Northgate
Partners, a Delaware Multiple Series LLC 
 Patrick Ennis 

Thomas S. Porter Restated Trust DTD 11-14-05 

Trellis Partners II, L.P. 
 UC
Berkeley Foundation 
 London Pacific Assurance Limited 

EDF Ventures II, Limited Partnership 

The Infrastructure Fund, LP 
 The
Infrastructure Co-Invest Fund, LP 

  
 4 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 2 TO 

SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

THIS AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT (this “Amendment”) is made and
entered into as of March 28, 2008 by and among Xtera Communications, Inc., a Delaware corporation (the “Company”), certain of the holders of the Company’s Common Stock, par value $0.001 per share (the
“Common Stock”), certain of the holders of the Company’s Series A-1 Convertible Preferred Stock, par value $0.001 per share (“Series A-1 Preferred Stock”), and certain of the holders of the
Company’s Series B-1 Convertible Preferred Stock, par value $0.001 per share (“Series B-1 Preferred Stock”), all as set forth on Schedule A attached to this Agreement (collectively, the “Consenting
Investors”), and each of the persons set forth on Schedule B attached to this Agreement (each a “New Investor,” and collectively, the “New Investors”). 

RECITALS 
 WHEREAS,
the Company, certain of the holders of the Common Stock and each of the holders of Series A-1 Preferred Stock and Series B-1 Preferred Stock previously entered into that certain Second Amended and Restated Investor Rights Agreement, dated
August 1, 2007, as amended (the “Investor Rights Agreement”); 
 WHEREAS, pursuant to the terms of that
certain Agreement and Plan of Merger dated as of March 28, 2008 by and among the Company, Meriton Acquisition Corp., and Meriton Networks, Inc. (the “Merger Agreement”), each New Investor shall receive
shares of Series B-1 Preferred Stock (the “New Shares”); 
 WHEREAS, as a condition to the closing of
the transactions contemplated by the Merger Agreement and the issuance of the New Shares to the New Investors, each New Investor must execute this Amendment and become a party to the Investor Rights Agreement; 

WHEREAS, Section 6.8 of the Investor Rights Agreement provides that it may only be amended with the written consent of the
party against whom enforcement of such amendment is sought; provided that the consent of the holders of more than 50% of the Registrable Securities (as defined in the Investor Rights Agreement) is sufficient to bind the holders of Series A-1
Preferred Stock and Series B-1 Preferred Stock (which majority must include the holders of a majority of the shares of the Series B-1 Preferred Stock); and 

WHEREAS, the undersigned, holding the requisite amount of stock necessary to amend the Investor Rights Agreement, desire to amend the
Investor Rights Agreement as provided herein. 
 AGREEMENT 

NOW, THEREFORE, in consideration of the foregoing, the mutual covenants herein contained and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows: 
 1. New Investors. Each New Investor
hereby agrees to become a party to the Investor Rights Agreement and to be bound by each and every term thereof. Each of the New Investors listed on Schedule B attached hereto is hereby added to Exhibit A to the Investor Rights
Agreement as a Series B-1 Investor, and each New Investor shall be deemed an Investor (as such term is defined the Investor Rights Agreement) for all purposes contained in the Investor Rights Agreement. 

 2. Counterparts. This Amendment may be executed in two or more counterparts, each of which
shall be deemed an original, but all of which together shall constitute one and the same instrument. 
 3. Titles and Subtitles. The
titles and subtitles used in this Amendment are used for convenience only and are not to be considered in construing or interpreting this Amendment. 

4. Entire Agreement. The Investor Rights Agreement, as modified by this Amendment, and the documents referred to herein and therein
constitute the entire agreement among the parties in respect of the subject matter hereof and thereof and no party shall be liable or bound to any other party in any manner by any warranties, representations or covenants except as specifically set
forth herein or therein. 

  
 47 

 IN WITNESS WHEREOF, the undersigned has executed this Amendment as of the date first set forth
above. 
  

			
	 COMPANY:
  

XTERA COMMUNICATIONS, INC.

		
	By:	 	/s/ Paul J. Colan
		 	Paul J. Colan
		 	Chief Financial Officer

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 NEW ENTERPRISE ASSOCIATES 10,

LIMITED PARTNERSHIP

		
	By:	 	 NEA Partners 10, Limited Partners
 Its general
Partner

		
	By:	 	/s/ Charles W. Newhall III
	Name:	 	Charles W. Newhall III
	Title:	 	General Partner

 
			
		
	Address:	 	 1119 St Paul Street
 Baltimore, MD
21202

  

			
	 NEW ENTERPRISE ASSOCIATES 9,

LIMITED PARTNERSHIP

		
	By:	 	 NEA Partners 9, Limited Partners
 Its general
Partner

		
	By:	 	/s/ Charles W. Newhall III
	Name:	 	Charles W. Newhall III
	Title:	 	General Partner

 
			
		
	Address:	 	 1119 St. Paul Street
 Baltimore, MD
21202

  

			
	NEA VENTURES 2000, L.P.
		
	By:	 	/s/ Pamela J. Clark
	Name:	 	Pamela J. Clark
	Title:	 	General Partner

 
			
		
	Address:	 	 1119 St Paul Street
 Baltimore, MD
21202

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	CSK-VC SUSTAINABILITY INVESTMENT FUND
		
	By:	 	 CSK VENTURE CAPITAL CO., LTD.,
 Its Investment
Manager

		
	By:	 	/s/ Hiromichi Tabata
	Name:	 	Hiromichi Tabata
	Title:	 	President & CEO
	
	Address:
	
	 5th Fl, Riviera Minami Aoyama Building

3-3-3 Minami-Aoyama, Minato-ku,
 Tokyo, 107-0062

JAPAN
 Attn: Alessandro Araldi

Tel: +81 -(0)3-5771-6411
 Fax: +81 -(0)3-5771-6412

E-mail: aaraldi@cskvc.co.jp

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 CONSENTING INVESTORS:
  

THE WELLCOME TRUST LIMITED,
 AS TRUSTEE OF THE WELLCOME
TRUST

		
	By:	 	/s/ Peter Pereira Gray
	Name:	 	Peter Pereira Gray
	Title:	 	Managing Director

 
			
		
	Address:	 	 215 Euston Road
 London NW1 2BE

United Kingdom

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
	
	CLIFFORD H. HIGGERSON
	
	/s/ Clifford H. Higgerson

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	COMVENTURES IV, L.P.
		
	By:	 	 ComVen IV, L.L.C
 Its General
Partner

		
	By:	 	/s/ ComVen IV, L.L.C.
	Title:	 	VP and General Counsel

 
			
		
	Address:	 	 305 Lytton Avenue
 Palo Alto, CA
94301

  

			
	COMVENTURES IV CEO FUND, L.P.
		
	By:	 	 ComVen IV, L.L.C.
 Its General
Partner

		
	By:	 	/s/ ComVen IV, L.L.C.
	Title:	 	VP and General Counsel

 
			
		
	Address:	 	 305 Lytton Avenue
 Palo Alto, CA
94301

  

			
	COMVENTURES IV ENTREPRENEURS’ FUND, L.P.
		
	By:	 	 ComVen IV, L.L.C.
 Its General
Partner

		
	By:	 	/s/ ComVen IV, L.L.C.
	Title:	 	VP and General Counsel

 
			
		
	Address:	 	 305 Lytton Avenue
 Palo Alto, CA
94301

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 ATLAS VENTURE FUND VI, L.P.

ATLAS VENTURE ENTREPRENEURS’ FUND VI, L.P.

		
	By:	 	 Atlas Venture Associates VI L.P.
 their general
partner

	By:	 	 Atlas Venture Associates VI, Inc.
 its general
partner

		
	By:	 	/s/ Atlas Venture Associates VI, Inc.
		 	Vice President

  

			
	ATLAS VENTURE FUND VI GMBH & CO, KG
		
	By:	 	 Atlas Venture Associates VI, L.P
 its managing
limited partner

	By:	 	 Atlas Venture Associates VI, Inc.
 its general
partner

		
	By:	 	/s/ Atlas Venture Associates VI, Inc.
		 	Vice President

 
			
		
	Address:	 	 890 Winter Street
 Suite 320

Waltham, MA 02451

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	TVM V INFORMATION TECHNOLOGY GMBH & CO. KG
		
	By:	 	/s/ Mark G. Cipriano
	Name:	 	Mark G. Cipriano
	Title:	 	Managing Limited Partner
		
	By:	 	/s/ Edward Braginsky
	Name:	 	Edward Braginsky
	Title:	 	Managing Limited Partner

 
			
		
	Address:	 	
		
		 	 Christopher Cobbold
 TVM Capital

Maximilianstr. 35, Entrance C
 D-80539 Munich

Germany

		
	With a copy to:	 	
		
		 	 Stefan Fischer
 TVM Capital

Maximilianstr. 35, Entrance C
 D-80539 Munich

Germany

		
	and to:	 	
		
		 	 Mark G. Cipriano
 TVM Capital

101 Arch Street, Suite 1950
 Boston, MA 02110

		
	USA	 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	EDF VENTURES II, LIMITED PARTNERSHIP
		
	By:	 	 Enterprise Ventures II, Limited Partnership,

Its General Partner

		
	By:	 	 EDM II, Inc.,
 Its General Partner

		
	By:	 	/s/ Linda M. Fingerle
	Name:	 	Linda M. Fingerle
	Title:	 	CFO, Asst. Secretary and Asst. Treasurer

  

			
	EDF VENTURES I, LIMITED PARTNERSHIP
		
	By:	 	 Enterprise Ventures, Limited Partnership,
 Its
General Partner

		
	By:	 	 EDM, Inc.,
 Its General Partner

		
	By:	 	/s/ Linda M. Fingerle
	Name:	 	Linda M. Fingerle
	Title:	 	CFO, Asst. Secretary and Asst. Treasurer

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	ACCEL EUROPE L.P.
		
	By:	 	 Accel Europe Associates L.P.,
 Its General
Partner

		
	By:	 	 Accel Europe Associates L.L.C.
 Its General
Partner

		
	By:	 	/s/ Accel Europe L.P.
		 	Attorney in Fact

  

			
	ACCEL EUROPE INVESTORS 2003 L.P.
		
	By:	 	 Accel Europe Associates L.L.C.
 Its General
partner

		
	By:	 	/s/ Accel Europe Investors 2003 L.P.
		 	Attorney in Fact

 
			
		
	Address:	 	 Accel Partners
 16 St. James St.

London SW1A 1ER, United Kingdom
 Phone: 011 44
20 7170 1000
 Facsimile: 011 44 20 7170 1099

		
	With a copy to:	 	
		
		 	 Richard Zamboldi
 Accel Partners

428 University Avenue
 Palo Alto, CA 94301

Phone: (650) 614-4800
 Facsimile: (650) 614-4880

E-mail: rzamboldi@accel.com

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	ARCH VENTURE FUND III, L.P.
		
	By:	 	 ARCH Venture Partners, LLC,
 Its General
Partner

		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director

  

			
	ARCH VENTURE FUND IV, L.P.
		
	By:	 	 ARCH Venture Partners IV, LLC,
 Its General
Partner

		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director

  

			
	ARCH ENTREPRENEURS FUND, L.P.
		
	By:	 	 ARCH Venture Partners IV, LLC,
 Its General
Partner

		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director

  

			
	ARCH VENTURE FUND IV A, L.P.
		
	By:	 	 ARCH Venture Partners IV, LLC,
 Its General
Partner

		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director

  

			
	ARCH VENTURE FUND VI, L.P.
		
	By:	 	 ARCH Venture Partners IV, LLC,
 Its General
Partner

		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	SEVIN ROSEN FUND VII L.P.
		
	By:	 	 SRB ASSOCIATES VII L.P.,
 Its General
Partner

		
	By:	 	/s/ John V. Jaggers
	Name:	 	John V. Jaggers
	Title:	 	General Partner

 
			
		
	Address:	 	 13455 Noel Rd., Suite 1670
 Dallas, TX
75240

  

			
	SEVIN ROSEN VII AFFILIATES FUND L.P.
		
	By:	 	 SRB ASSOCIATES VII L.P.,
 Its General
Partner

		
	By:	 	/s/ John V. Jaggers
	Name:	 	John V. Jaggers
	Title:	 	General Partner

 
			
		
	Address:	 	 13455 Noel Rd., Suite 1670
 Dallas, TX
75240

  

			
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	/s/ John V. Jaggers
	Name:	 	John V. Jaggers
	Title:	 	Vice President

 
			
		
	Address:	 	 13455 Noel Rd., Suite 1670
 Dallas, TX
75240

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 QUESTER VENTURE PARTNERSHIP

acting by its general partner
 Quester Venture GP
Ltd

		
	By:	 	/s/ Sergio Len
	Name:	 	Sergio Len
	Title:	 	Director

  

			
	 QUESTER VCT 4 PLC
 acting
by its Manager
 Spark Venture Management Ltd.

		
	By:	 	/s/ Sergio Len
	Name:	 	Sergio Len
	Title:	 	Director

  

			
	 QUESTER VCT 5 PLC
 acting
by its Manager
 Spark Venture Management Ltd.

		
	By:	 	/s/ Sergio Len
	Name:	 	Sergio Len
	Title:	 	Director

 
			
		
	Address:	 	 Spark Venture Management Limited
 33
Glasshouse Street
 London
 W1B 5DG

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 NEW INVESTORS:
  

VANTAGEPOINT VENTURE PARTNERS IV (Q), LP
 by
VantagePoint Venture Associates IV, LLC
 its General Partner

		
	By:	 	/s/ Alan E. Salzman
	Name:	 	Alan E. Salzman
	Title:	 	Managing Member

 
			
		
	    Address:	 	 VantagePoint Venture Partners
 1001 Bayhill
Drive, Suite 300
 San Bruno, CA 94066

		
	    Facsimile:	 	

  

			
	 VANTAGEPOINT VENTURE PARTNERS IV, LP

by VantagePoint Venture Associates IV, LLC
 its General
Partner

		
	By:	 	/s/ Alan E. Salzman
	Name:	 	Alan E. Salzman
	Title:	 	Managing Member

 
			
		
	    Address:	 	 VantagePoint Venture Partners
 1001 Bayhill
Drive, Suite 300
 San Bruno, CA 94066

		
	    Facsimile:	 	

  

			
	 VANTAGEPOINT VENTURE PARTNERS IV PRINCIPALS FUND, LP

by VantagePoint Venture Associates IV, LLC
 its General
Partner

		
	By:	 	/s/ Alan E. Salzman
	Name:	 	Alan E. Salzman
	Title:	 	Managing Member

 
			
		
	    Address:	 	 VantagePoint Venture Partners
 1001 Bayhill
Drive, Suite 300
 San Bruno, CA 94066

		
	    Facsimile:	 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 INVESTORS:
  

NEWBURY VENTURES III, LP

		
	By:	 	/s/ David J. Kapnick
	Name:	 	David J. Kapnick
	Title:	 	Chief Financial Officer
	Address:	 	 255 Shoreline Drive
 Suite 520

Redwood Shores, CA 94065

	Facsimile:	 	(650) 595-2442

  

			
	Newbury Ventures III GmbH & Co. KG
		
	By:	 	/s/ David J. Kapnick
	Name:	 	David J. Kapnick
	Title:	 	Chief Financial Officer
	Address:	 	 255 Shoreline Drive
 Suite 520

Redwood Shores, CA 94065

	Facsimile:	 	(650) 595-2442

  

			
	NEWBURY VENTURES CAYMAN III, LP
		
	By:	 	/s/ David J. Kapnick
	Name:	 	David J. Kapnick
	Title:	 	Chief Financial Officer
	Address:	 	 255 Shoreline Drive
 Suite 520

Redwood Shores, CA 94065

	Facsimile:	 	(650) 595-2442

  

			
	NEWBURY VENTURES EXECUTIVES III, LP
		
	By:	 	/s/ David J. Kapnick
	Name:	 	David J. Kapnick
	Title:	 	Chief Financial Officer
	Address:	 	 255 Shoreline Drive
 Suite 520

Redwood Shores, CA 94065

	Facsimile:	 	(650) 595-2442

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

									
	INVESTORS:	 		 	
			
	JERUSALEM VENTURE PARTNERS IV, L.P.	 		 	JERUSALEM VENTURE PARTNERS IV-A, L.P.
					
	By:	 	/s/ Jerusalem Venture Partners IV, L.P.	 		 	By:	 	/s/ Jerusalem Venture Partners IV-A, L.P.
	Name:	 	 	 		 	Name:	 	 
	Title:	 	 	 		 	Title:	 	 
					
	Address:	 	 7 West 22nd Street, 7th Floor
 New York, NY
10010
	 		 	Address:	 	 7 West 22nd Street, 7th Floor
 New York, NY
10010

  

									
	JERUSALEM VENTURE PARTNERS ENTREPRENEURS FUND IV, L.P.	 		 	JERUSALEM VENTURE PARTNERS IV (ISRAEL), L.P.
					
	By:	 	/s/ Jerusalem Venture Partners Entrepreneurs Fund IV, L.P.	 		 	By:	 	/s/ Jerusalem Venture Partners IV (Israel), L.P.
	Name:	 	 	 		 	Name:	 	 
	Title:	 	 	 		 	Title:	 	 
					
	Address:	 	 7 West 22nd Street, 7th Floor
 New York, NY
10010
	 		 	Address:	 	 Jerusalem Technology Park, Bldg. 1
 Malha,
Jerusalem 91487
 ISRAEL

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 NEW INVESTORS:
  

VENTURE COACHES FUND LP
 by its General Partner,

Venture Coaches Limited

		
	By:	 	/s/ Claude Haw
	Name:	 	Claude Haw
	Title:	 	President

 
			
		
	Address:	 	 555 Legget Dr., Tower B, Suite 830
 Kanata,
ON K2K 2X3
 CANADA

	Telephone:	 	(613) 271-1500
	Facsimile:	 	(613) 270-1505

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

							
		 		 	 NEW INVESTORS:
  

KLAUS BUSCH

				
	 	 		 	By:	 	/s/ Klaus Busch
	Witness	 		 		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

							
		 		 	 NEW INVESTORS:
  

MICHAEL PASCOE

				
	 	 		 	By:	 	/s/ Michael Pascoe
	Witness	 		 		 	Michael Pascoe

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 NEW INVESTORS:
  

THE VENGROWTH INVESTMENT FUND INC.

		
	By:	 	/s/ Patrick DiPietro
	Name:	 	Patrick DiPietro
	Title:	 	Managing General Partner
		
	By:	 	/s/ Jay Heller
	Name:	 	Jay Heller
	Title:	 	General Partner

 
			
	Address:	 	 c/o VenGrowth Capital
 Management Inc.

411 Legget Drive, Suite 705
 Kanata, Ontario

Canada K2K 3C9
 Attention: Pat DiPietro

	Facsimile:	 	(613) 591-7377
		
	With a copy to:	 	
		
	Address:	 	 c/o VenGrowth Capital
 Management Inc.

105 Adelaide Street, West
 Suite 1000

Toronto, Ontario
 Canada M5H 1P9

	Facsimile:	 	(416) 971-6519

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 NEW INVESTORS:
  

THE VENGROWTH II INVESTMENT FUND INC.

		
	By:	 	/s/ Patrick DiPietro
	Name:	 	Patrick DiPietro
	Title:	 	Managing General Partner
		
	By:	 	/s/ Jay Heller
	Name:	 	Jay Heller
	Title:	 	General Partner

 
			
	Address:	 	 c/o VenGrowth Capital
 Management Inc.

411 Legget Drive, Suite 705
 Kanata, Ontario

Canada K2K 3C9
 Attention: Pat DiPietro

	Facsimile:	 	(613) 591-7377
		
	With a copy to:	 	
		
	Address:	 	 c/o VenGrowth Capital
 Management Inc.

105 Adelaide Street, West
 Suite 1000

Toronto, Ontario
 Canada M5H 1P9

Attention: Jay Heller

	Facsimile:	 	(416) 971-6519

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 NEW INVESTORS:
  

THE VENGROWTH III INVESTMENT FUND INC.

		
	By:	 	/s/ Patrick DiPietro
	Name:	 	Patrick DiPietro
	Title:	 	Managing General Partner
		
	By:	 	/s/ Jay Heller
	Name:	 	Jay Heller
	Title:	 	General Partner

 
			
	Address:	 	 c/o VenGrowth Capital
 Management Inc.

411 Legget Drive, Suite 705
 Kanata, Ontario

Canada K2K 3C9
 Attention: Pat DiPietro

	Facsimile:	 	(613) 591-7377
		
	With a copy to:	 	
		
	Address:	 	 c/o VenGrowth Capital
 Management Inc.

105 Adelaide Street, West
 Suite 1000

Toronto, Ontario
 Canada M5H 1P9

Attention: Jay Heller

	Facsimile:	 	(416) 971-6519

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 NEW INVESTORS:
  

DESJARDINS VENTURE CAPITAL, L.P., formerly known as ID, Limited Partnership herein acting by Desjardins Venture Capital Inc., its general
partner

		
	By:	 	/s/ Luc Menard
	Name:	 	Luc Menard
	Title:	 	Sector Director
		
	By:	 	/s/ Leon Lajoie
	Name:	 	Leon Lajoie
	Title:	 	Investment Director

 
			
		
	Address:	 	 2 Complexe Desjardins
 Suite 1717

Montreal, Quebec
 Canada H5B 1B8

	Facsimile:	 	(514) 281-7808

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 SCHEDULE A 

CONSENTING INVESTORS 
 THE WELLCOME TRUST
LIMITED, AS TRUSTEE OF THE WELLCOME TRUST 
 NEW ENTERPRISE ASSOCIATES 10, L.P. 

NEW ENTERPRISE ASSOCIATES 9, L.P. 
 ARCH VENTURE FUND III, L.P.

 ARCH VENTURE FUND IV, L.P. 
 ARCH ENTREPRENEURS FUND, L.P.

 ARCH VENTURE FUND IV A, L. P. 
 ARCH VENTURE FUND VI, L.P.

 SEVIN ROSEN FUND VII, L.P. 
 SEVIN ROSEN VII AFFILIATES FUND,
L.P. 
 COMVENTURES IV, L.P. 
 COMVENTURES IV CEO FUND, L.P.

 COMVENTURES IV ENTREPRENEURS’ FUND, L.P. 
 EDF VENTURES
II, LIMITED PARTNERSHIP 
 EDF VENTURES I, LIMITED PARTNERSHIP 

REGENTS OF THE UNIVERSITY OF MICHIGAN 
 ACCEL EUROPE L.P. 

ACCEL EUROPE INVESTORS 2003 L.P. 
 ATLAS VENTURE FUND VI, L.P.

 ATLAS VENTURE FUND VI GMBH & CO. KG 
 ATLAS VENTURE
ENTREPRENEURS’ FUND VI, L.P. 
 QUESTER VENTURE PARTNERSHIP 

QUESTER VCT 4 PLC 
 QUESTER VCT 5 PLC 

 LAGO VENTURES FUND ONE LIMITED 

TVM V INFORMATION TECHNOLOGY GMBH & CO. KG 
 CSK-VC
SUSTAINABILITY INVESTMENT FUND 

  
 2 

 SCHEDULE B 

NEW INVESTORS 
 VANTAGEPOINT VENTURE
PARTNERS IV (Q), LP 
 VANTAGEPOINT VENTURE PARTNERS IV, LP 

VANTAGEPOINT VENTURE PARTNERS IV PRINCIPALS FUND, LP 
 NEWBURY
VENTURES III, LP 
 NEWBURY VENTURES III GMBH & Co. KG 

NEWBURY VENTURES CAYMAN III, LP 
 NEWBURY VENTURES EXECUTIVES III,
LP 
 DESJARDINS VENTURE CAPITAL, L.P. 
 JERUSALEM VENTURE
PARTNERS IV, L.P. 
 JERUSALEM VENTURE PARTNERS IV-A, L.P. 

JERUSALEM VENTURE PARTNERS ENTREPRENEURS FUND IV, L.P. 
 JERUSALEM
VENTURE PARTNERS IV (ISRAEL), L.P. 
 VENTURE COACHES FUND LP 

KLAUS BUSCH 
 MICHAEL PASCOE 

THE VENGROWTH INVESTMENT FUND INC. 
 THE VENGROWTH II INVESTMENT
FUND INC. 
 THE VENGROWTH III INVESTMENT FUND INC. 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 5 TO 

SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

THIS AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT (this “Amendment”)
is made and entered into as of September 23, 2011 by and among Xtera Communications, Inc., a Delaware corporation (the “Company”), certain of the holders of the Company’s Series A-3 Convertible
Preferred Stock, par value $0.001 per share (“Series A-3 Preferred Stock”), certain of the holders of the Company’s Series B-3 Convertible Preferred Stock, par value $0.001 per share
(“Series B-3 Preferred Stock”) and certain of the holders of the Company’s Series C-3 Convertible Preferred Stock, par value $0.001 per share (“Series C-3 Preferred
Stock”), all as set forth on Schedule A attached to this Amendment (collectively, the “Consenting Investors”), and each of the persons set forth on Schedule B attached
to this Amendment (each a “New Investor,” and collectively, the “New Investors”). 

RECITALS 

WHEREAS, the Company, certain of the holders of the Common Stock, Series A-2 Preferred Stock, Series B-2
Preferred Stock and Series C-2 Preferred Stock previously entered into the Second Amended and Restated Investor Rights Agreement, dated August 1, 2007, as amended (the “Investor Rights Agreement”); 

WHEREAS, Section 6.8 of the Investor Rights Agreement provides that it may only be amended with the written consent of the
party against whom enforcement of such amendment is sought; provided that the consent of the holders of more than 50% of the Registrable Securities (as defined in the Investor Rights Agreement) is sufficient to bind the holders of Series A-2
Preferred Stock, Series B-2 Preferred Stock and Series C-2 Preferred Stock (which majority must include the holders of a majority of the shares of the Series C-2 Preferred Stock); 

WHEREAS, pursuant to the terms of that certain Series D-3
Preferred Stock Purchase Agreement, by and among the Company and the Investors purchasing shares of the Company’s Series D-3 Preferred Stock, par value $0.001 per share (the “Series D-3 Preferred Stock”) dated on or about the date hereof (the “Purchase Agreement”), participating Investors exchanged their shares of
Series A-2 Preferred Stock, Series B-2 Preferred Stock and Series C-2 Preferred Stock for shares of Series A-3 Preferred Stock, Series B-3 Preferred Stock and Series C-3 Preferred Stock; 

WHEREAS, pursuant to the Amended and Restated Certificate of Incorporation of the Company as filed with the Delaware Secretary of State
on September 22, 2011, each share of Series A-2 Preferred Stock, Series B-2 Preferred Stock and Series C-2 Preferred Stock outstanding on September 24, 2011 shall automatically convert into Common Stock; 

WHEREAS, pursuant to the Purchase Agreement, each New Investor shall receive shares of Series D-3
Preferred Stock (the “New Shares”); 
 WHEREAS, as a condition to the closing of the
transactions contemplated by the Purchase Agreement and the issuance of the New Shares to the New Investors, each New Investor must execute this Amendment and become a party to the Investor Rights Agreement; and 

WHEREAS, the undersigned, holding the requisite amount of stock necessary to amend the Investor Rights Agreement, desire to amend the
Investor Rights Agreement as provided herein.  

 AGREEMENT 

NOW, THEREFORE, in consideration of the foregoing, the mutual covenants herein contained and other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows: 
 1. New Investors. Each New
Investor hereby agrees to become a party to the Investor Rights Agreement and to be bound by each and every term thereof. Each of the New Investors listed on Schedule B attached hereto is hereby added to Exhibit A to the Investor Rights Agreement as
a Series D-3 Investor, and each New Investor shall be deemed an Investor (as such term is defined the Investor Rights Agreement) for all purposes contained in the Investor Rights Agreement. 

2. Amended Provisions. The Investor Rights Agreement is hereby amended such that: 

Section 3.1(e) Registrable Securities is hereby replaced in its entirety with the following: 

“(e) Registrable Securities. The term “Registrable Securities” means: (i) all shares of Common Stock
held by any Investor, (ii) all shares of Common Stock issued or issuable pursuant to the conversion of the Series A-3 Preferred Stock, Series B-3 Preferred Stock, Series C-3 Preferred Stock and Series D-3 Preferred Stock (collectively, the
“Preferred Stock”), (iii) all shares of Common Stock issued or issuable pursuant to the exercise of warrants to purchase Common Stock held by any Investor, (iv) solely for purposes of Section 3.3 hereof,
shares of Common Stock held by or issuable upon the exercise of warrants or conversion of Preferred Stock held by certain financial and educational institutions, and (v) any shares of Common Stock or other securities of the Company issued in
connection with any stock split, stock dividend, recapitalization or similar event relating to any of the foregoing; excluding in all cases, however, any Registrable Securities sold by a person in a transaction in which the rights under this
Section 3 are not assigned in accordance with this Agreement or any Registrable Securities sold to the public or sold pursuant to Rule 144 promulgated under the Securities Act.” 

The references to “Series C-2” in Clause (i) and Clause (vi) of Section 4.2(a) New Securities and in
Section 6.8 Amendments and Waivers are hereby replaced with the term “Series D-3.” 
 All other references to
“Series A-2” not otherwise amended herein are hereby replaced with the term “Series A-3.” 
 All other references to “Series
B-2” not otherwise amended herein are hereby replaced with the term “Series B-3.” 
 All other references to “Series C-2” not
otherwise amended herein are hereby replaced with the term “Series C-3.” 
 3. Counterparts. This Amendment may be executed
in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. 

4. Titles and Subtitles. The titles and subtitles used in this Amendment are used for convenience only and are not to be considered in
construing or interpreting this Amendment. 
 5. Entire Agreement. The Investor Rights Agreement, as modified by this Amendment, and
the documents referred to herein and therein constitute the entire agreement among the parties in respect 

  
 75 

 
of the subject matter hereof and thereof and no party shall be liable or bound to any other party in any manner by any warranties, representations or covenants except as specifically set forth
herein or therein. 
 Signature Pages Follow 

  
 76 

 IN WITNESS WHEREOF, the undersigned has executed this Amendment as of the date first set forth
above. 
  

			
	 COMPANY:
  

XTERA COMMUNICATIONS, INC.

		
	By:	 	/s/ Paul J. Colan
		 	Paul J. Colan
		 	Chief Financial Officer

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
					
	 INVESTORS:
  

ACCEL EUROPE L.P.

		
	By:	 	Accel Europe Associates L.P.
		 	its General Partner
	By:	 	Accel Europe Associates L.L.C.
		 	its General Partner
			
		 	By:	 	/s/ Accel Europe L.P.
		 	Name:	 	Accel Europe L.P.
		 	Title:	 	Attorney in Fact

 
					
			
		 	Address:	 	 428 University Ave.
 Palo Alto, CA
94301-1812

  

					
	ACCEL EUROPE INVESTORS 2003, L.P.
		
	By:	 	Accel Europe Investors 2003 L.P.
		 	its General Partner
	By:	 	Accel Europe Associates L.L.C.
		 	its General Partner
			
		 	By:	 	/s/ Accel Europe Investors 2003, LP
		 	Name:	 	Accel Europe Investors 2003, L.P.
		 	Title:	 	Attorney in Fact

 
					
			
		 	Address:	 	 428 University Ave.
 Palo Alto, CA
94301-1812

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	 INVESTORS:
  

JAMES R. ADOX

	
	/s/ James R. Adox

 
			
		
	Address:	 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	ARCH VENTURE FUND III, L.P.
	
	 ARCH Venture Partners, LLC,
 Its
General Partner

		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director
	
	ARCH VENTURE FUND IV, L.P.
	
	 ARCH Venture Partners IV, LLC,
 Its
General Partner

		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director
	
	ARCH VENTURE FUND IV A, L.P.
	
	 ARCH Venture Partners IV, LLC,
 Its
General Partner

		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director
	
	ARCH ENTREPRENEURS FUND, L.P.
	
	 ARCH Venture Partners IV, LLC,
 Its
General Partner

		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director
	
	ARCH VENTURE FUND VI, L.P.
	
	 ARCH Venture Partners IV, LLC,
 Its
General Partner

		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director
	Address:	 	 
		 	 

  
  

COUNTERPART SIGNATURE TO 

AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	STUART BARNES
	
	/s/ Stuart Barnes
		
	Address:	 	 
		 	 
		 	 
		 	 
		 	 
		 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	TIMOTHY RUSSELL DAVISON
	
	/s/ Timothy Russell Davison
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	STEVEN DESBRUSLAIS
	
	/s/ Steven Desbruslais
		
	Address:	 	 
		 	 
		 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	JOHN ELLISON
	
	/s/ John Ellison
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	PATRICK ENNIS
	
	/s/ Patrick Ennis
		
	Address:	 	3150 139th Avenue SE
		 	Building 4
		 	Bellevue, WA 98005

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	MICHAEL HAMILTON-SMITH
	
	/s/ Michael Hamilton-Smith
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	HAYDEN HARRIS
	
	/s/ Hayden Harris
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	 HAYDEN H. HARRIS LIVING TRUST

DTD. 3-6-98

	
	/s/ Hayden Harris
	Name:	 	Hayden Harris
	Title:	 	Trustee
		
	Address:	 	
		 	

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	CLIFFORD HIGGERSON
	
	/s/ Clifford H. Higgerson
		
	Address:	 	361 Lytton Avenue, 2nd Floor
		 	Palo Alto, CA 94301

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	 INDEPENDENT WEALTH MANAGEMENT

CONSULTANTS LIMITED

		
	By:	 	/s/ Timothy Russell Davison
	Name:	 	Timothy Davison
	Title:	 	Director
		
	Address:	 	14 Exchange Street
		 	Retford DN22 6BL

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	ANTHONY JEFFRIES
	
	/s/ Anthony Jeffries
		
	Address:	 	(same)
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	RUSSELL JOHNSON
	
	/s/ Russell Johnson
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	JON BAYLESS, SEPARATE PROPERTY
	
	/s/ Jon Bayless
	Address:	 	 13455 Noel Road, Suite 1670
 Two Galleria
Tower
 Dallas, TX 75240

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	LAGO VENTURES FUND ONE LIMITED
		
	By:	 	/s/ Arvind Gulati
	Name:	 	    Arvind Gulati
	Title:	 	    Director Representative
	Address:	 	 c/o Cayside Trust Company Limited
 Lyford Cay
House, 6th Floor
 Western Road
 P.O. Box N-7776 (Slot 193)

Lyford Cay, New Providence
 The Bahamas

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	BEAU D. LASKEY
	
	/s/ Beau Laskey
	Address:	 	 
		 	

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	MOHR SEED CAPITAL II LP
		
	By:	 	/s/ Robert Mohr
	Name:	 	Robert Mohr
	Title:	 	Owner
		
	Address:	 	14643 Dallas Parkway, Ste 1000
		 	Dallas, TX 75254

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
					
		 	INVESTORS:
		
		 	NEW ENTERPRISE ASSOCIATES 10, L.P.
		
	By:	 	 NEA Partners 10, L.P.
 Its General
Partner

			
		 	By:	 	/s/ Louis S. Citron
		 	Name:	 	Louis S. Citron
		 	Title:	 	Attorney-in-Fact
		 	Address:	 	 2490 Sand Hill Road
 Menlo Park, CA
94025

		
		 	NEW ENTERPRISE ASSOCIATES 9, L.P.
		
	By:	 	 NEA Partners 9, L.P.
 Its General
Partner

			
		 	By:	 	/s/ Louis S. Citron
		 	Name:	 	Louis S. Citron
		 	Title:	 	Attorney-in-Fact
		 	Address:	 	 2490 Sand Hill Road
 Menlo Park, CA
94025

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 INVESTORS: 
  

									
	NEWBURY VENTURES III, LP *	 		 	NEWBURY VENTURES CAYMAN III, LP *
					
	By:	 	/s/ Joseph Kell	 		 	By:	 	/s/ Joseph Kell
					
	Name:	 	Joseph Kell	 		 	Name:	 	Joseph Kell
					
	Title:	 	CFO	 		 	Title:	 	CFO
					
	Address:	 	255 Shoreline Drive, # 520	 		 	Address:	 	Same
		 	Redwood Shores, CA 94065	 		 		 	
			
	NEWBURY VENTURES III GMNH & CO, KG**	 		 	NEWBURY VENTURES EXECUTIVES III, LP *
					
	By:	 	/s/ Joseph Kell	 		 	By:	 	/s/ Joseph Kell
					
	Name:	 	Joseph Kell	 		 	Name:	 	Joseph Kell
					
	Title:	 	CFO	 		 	Title:	 	CFO
					
	Address:	 	Same	 		 	Address:	 	Same

  

							
	*	 	By:	  	Newbury Venture Partners III, LLC	  	
		 	Its:	  	General Partner	  	
				
	**    	 	By:	  	Newbury Venture Partners III, LLC	  	
		 	Its:	  	Managing Limited Partner	  	

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	NORTHGATE PARTNERS LLC, a Delaware Multiple Series LLC
		
	By:	 	/s/ Mark Harris
	Name:	 	Mark Harris
	Title:	 	Managing Member
		
	Address:	 	649 San Ramon Valley Blvd
		 	Danville, CA 94526

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	THE RAHN GROUP
		
	By:	 	/s/ The Rahn Group
	Name:	 	 
	Title:	 	 
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	 RELL FAMILY PARTNERS, LTD.,

a Colorado Limited Partnership

		
	By:	 	/s/ Richard N. Frasch, MGP
	Name:	 	Richard N. Frasch
	Title:	 	Managing General Partner
		
	Address:	 	3212 Baker Str.
		 	San Francisco, CA 94123

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 INVESTORS: 
  

									
	RHO MANAGEMENT TRUST I	 		 	RHO VENTURES IV GMBH & CO. BETEILIGUNGS KG
					
	By:	 	RHO CAPITAL PARTNERS INC.	 		 	By:	 	RHO CAPITAL PARTNERS VERWALTONGS GMBH
					
	By:	 	/s/ Jeffrey Martin	 		 	By:	 	/s/ Jeffrey Martin
					
	Name:	 	Jeffrey Martin	 		 	Name:	 	Jeffrey Martin
					
	Title:	 	Attorney-in-fact	 		 	Title:	 	Attorney-in-fact
					
	Address*	 		 		 	Address*	 	
		 		 		 		 	
			
	RHO VENTURES IV (QP) L.P.	 		 	RHO VENTURES IV L.P.
					
	By:	 	RHO MANAGEMENT VENTURES, IV, LLC	 		 	By:	 	RHO MANAGEMENT VENTURES IV, L.L.C.
					
	By:	 	/s/ Jeffrey Martin	 		 	By:	 	/s/ Jeffrey Martin
					
	Name:	 	Jeffrey Martin	 		 	Name:	 	Jeffrey Martin
					
	Title:	 	Attorney-in-fact	 		 	Title:	 	Attorney-in-fact
					
	Address*	 		 		 	*Address:	 	 
		 		 		 		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	DAVE SEGRE
	
	/s/ David J. Segre
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	SEVIN ROSEN FUND VII, L.P.
	
	 SRB ASSOCIATES VII L.P.
 Its General
Partner

		
	By:	 	/s/ John V. Jaggers
	Name:	 	John V. Jaggers
	Title:	 	General Partner
	Address:	 	     c/o Sevin Rosen Funds

    13455 Noel Road, Suite 1670

    Dallas, TX 75240

	
	SEVIN ROSEN VII AFFILIATES FUND, L.P.
		
	By:	 	 SRB ASSOCIATES VII L.P.
 Its General
Partner

		
	By:	 	/s/ John V. Jaggers
	Name:	 	John V. Jaggers
	Title:	 	General Partner
	Address:	 	     c/o Sevin Rosen Funds

    13455 Noel Road, Suite 1670

    Dallas, TX 75240

	
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	/s/ John V. Jaggers
	Name:	 	John V. Jaggers
	Title:	 	Vice President
	Address:	 	     c/o Sevin Rosen Funds

    13455 Noel Road, Suite 1670

    Dallas, TX 75240

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

					
	Star Growth Enterprise, a German Civil Law Partnership (with limitation of liability)
	By:	 	SVM Star Ventures Managementgesellschaft mbH Nr. 3
	Title:	 	Managing Partner
		
	/s/ Meir Barel	 	
	By:	 	Dr. Meir Barel	 	
	Title:	 	Managing Director	 	
	
	SVM Star Ventures Managementgesellschaft mbH Nr. 3 and Co. Beteiligungs KG Nr. 3
	By:	 	SVM Star Ventures Managementgesellschaft mbH Nr. 3
	Title:	 	Managing Partner
		
	/s/ Meir Barel	 	
	By:	 	Dr. Meir Barel	 	
	Title:	 	Managing Director	 	
	
	SVM Star Ventures Managementgesellschaft mbH Nr. 3
		
	/s/ Meir Barel	 	
	By:	 	Dr. Meir Barel	 	
	Title:	 	Managing Director	 	
	
	SVE Star Ventures Enterprises GmbH & Co. No. IX KG
	By:	 	SVM Star Ventures Managementgesellschaft mbH Nr. 3
	Title:	 	Managing Partner
		
	/s/ Meir Barel	 	
	By:	 	Dr. Meir Barel	 	
	Title:	 	Managing Director	 	
	
	Star Management of Investments No. II (2000) L.P.
	By:	 	SVM STAR Venture Capital Management Ltd.
	Title:	 	Managing Partner
		
	/s/ Meir Barel	 	
	By:	 	Dr. Meir Barel	 	
	Title:	 	Director	 	

 {Signature Page Xtera Communications, Inc., Amendment No. 5 to Second Amended and Restated Investors
Rights Agreement} 
 September 23, 2011 

 
			
	INVESTORS:
	
	JOHN TEEGEN
	
	/s/ John Teegen
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	 THOMAS A. KELLEY & ASSOCIATES

PROFIT SHARING PLAN

		
	By:	 	/s/ Tom A. Kelley
	Name:	 	Tom A. Kelley
	Title:	 	Trustee of Plan
		
	Address:	 	5 Franciscan Ridge
		 	Portola Valley, California 94028-8043

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	 THOMAS S. PORTER RESTATED TRUST

DTD. 7-31-98

		
	By:	 	/s/ Thomas S. Porter
	Name:	 	Thomas S. Porter
	Title:	 	Trustee
		
	Address:	 	
		 	

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	 THOMAS S. PORTER RESTATED TRUST

DTD. 11-14-05

		
	By:	 	/s/ Thomas S. Porter
	Name:	 	Thomas S. Porter
	Title:	 	Trustee
		
	Address:	 	
		 	

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	 TIMOTHY RUSSELL DAVISON AS TRUSTEE

UNDER A DECLARATION OF TRUST
 DATED 30 APRIL
2010

		
	By:	 	/s/ Timothy Davison
	Name:	 	Timothy Davison
	Title:	 	Trustee
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	ARTHUR TRUEGER
	
	/s/ Arthur Trueger
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	 UNIVERSITY OF ILLINOIS

FOUNDATION

		
	By:	 	/s/ Laura A. Vossman
	Name:	 	Laura A. Vossman
	Title:	 	Assistant Treasurer
		
	Address:	 	1305 W. Green St.
		 	Urbana, IL 61801

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 INVESTORS: 
  

									
	VANTAGEPOINT VENTURE PARTNERS IV, LP	 		 	VANTAGEPOINT VENTURE PARTNERS IV PRINCIPALS FUND, LP
					
	By:	 	 VANTAGEPOINT VENTURE
 ASSOCIATES IV,
L.L.C.
	 		 	By:	 	 VANTAGEPOINT VENTURE
 ASSOCIATES IV,
L.L.C.

					
	By:	 	/s/ Alan E. Salzman	 		 	By:	 	/s/ Alan E. Salzman
					
	Name:	 	Alan E. Salzman	 		 	Name:	 	Alan E. Salzman
					
	Title:	 	Managing Member	 		 	Title:	 	Managing Member
					
	*Address	 		 		 	*Address	 	
		 		 		 		 	
				
	VANTAGEPOINT VENTURE PARTNERS IV (Q), LP	 		 		 	
					
	By:	 	VANTAGEPOINT VENTURE	 		 	*Address:	 	VantagePoint Capital Partners
		 	ASSOCIATES IV, L.L.C.	 		 		 	1001 Bayhill Drive Suite 300
		 		 		 		 	San Bruno CA 94066
					
	By:	 	/s/ Alan E. Salzman	 		 		 	
					
	Name:	 	Alan E. Salzman	 		 		 	
					
	Title:	 	Managing Member	 		 		 	
					
	*Address	 		 		 		 	

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	STEPHEN WEBB
	
	/s/ S.M. Webb
	Address:	 	 
		 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	 THE WELLCOME TRUST LIMITED,

AS TRUSTEE OF THE WELLCOME TRUST

		
	By:	 	/s/ Peter Pereira Gray
	Name:	 	Peter Pereira Gray
	Title:	 	Managing Director, Investments
	Address:	 	215 Euston Road,
		 	London NW1 2BE,
		 	United Kingdom

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	SCOTT WHITE
	
	/s/ Scott White
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	DAVID WINTERBURN
	
	/s/ David Winterburn
	Address:	 	 
		 	 
		 	 
		 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 
			
	INVESTORS:
	
	WS INVESTMENT 99B
		
	By:	 	/s/ WS Investment 99B
	Name:	 	 
	Title:	 	 
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE TO

 AMENDMENT NO. 5 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

 SCHEDULE A 

CONSENTING INVESTORS 
 Accel Europe
Investors 2003, L.P. 
 Accel Europe L.P. 
 Adox, James R. 

ARCH Entrepreneurs Fund, L.P. 
 ARCH Venture Fund III, L.P. 

ARCH Venture Fund IV A, L.P. 
 ARCH Venture Fund IV, L.P. 

ARCH Venture Fund VI, L.P. 
 Barnes, Stuart 

Jon W. Bayless, Separate Property 
 Trueger, Arthur 

Davison, Timothy Russell 
 Desbruslais, Steven 

Ellison, John 
 Ennis, Patrick J. 

Hamilton-Smith, Michael 
 Harris, Hayden 

Hayden H. Harris Living Trust 
 Higgerson, Clifford H. 

Independent Wealth Management Consultants Limited 
 Jeffries,
Anthony 
 Johnson, Russell 
 Lago Ventures Fund One Limited

 Laskey, Beau Daniel 
 Mohr Seed Capital II, L.P. 

New Enterprise Associates 10, L.P. 
 New Enterprise Associates 9,
L.P. 
 Newbury Ventures Cayman III, LP 
 Newbury Ventures
Executives III, LP 
 Newbury Ventures III GmbH & Co. KG 

Newbury Ventures III, LP 
 Northgate Partners LLC, a Delaware
Multiple Series LLC 
 Rahn Group 
 Rell Family Partners Limited

 Rho Management Trust I 
 Rho Ventures IV (QP), L.P. 

 Rho Ventures IV GmbH & Co. Beteiligungs KG 

Rho Ventures IV, L.P. 
 Segre, Dave 

Sevin Rosen Bayless Management Company 
 Sevin Rosen Fund VII,
L.P. 
 Sevin Rosen VII Affiliates Fund L.P. 
 Star Growth
Enterprise, a German Civil Law Partnership 
 Star Management Of Investments No. 2 (2000) L.P. 

SVE Star Ventures Enterprises GmbH & Co. No. IX KG 
 SVM
Star Ventures Managementgesellschaft MbH Nr. 3 
 SVM Star Ventures Managementgesellschaft MbH Nr. 3 & Co. Beteiligungs KG Nr. 3 

Teegen, John 
 Thomas A. Kelley & Associates Profit
Sharing Plan 
 Thomas S. Porter Restated Trust dated 11-14-05 

Thomas S. Porter Restated Trust dated 7-31-98 
 Timothy Russell
Davison as Trustee under a Declaration of Trust dated 30 April 2010 
 University Of Illinois Foundation 

VantagePoint Venture Partners IV (Q), LP 
 VantagePoint Venture
Partners IV Principals Fund, LP 
 VantagePoint Venture Partners IV, LP 

Webb, Stephen 
 Wellcome Trust Limited, as Trustee of the Wellcome
Trust 
 White, Scott 
 Winterburn, David 

WS Investment 99B 

  
 2 

 SCHEDULE B 

NEW INVESTORS 
 None. 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 6 TO 

SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT 

THIS AMENDMENT NO. 6 TO SECOND AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT (this “Amendment”) is made and
entered into as of August 25, 2015 by and among Xtera Communications, Inc., a Delaware corporation (the “Company”), certain of the holders of the Company’s Series A-3 Convertible Preferred Stock, par value $0.001
per share (“Series A-3 Preferred Stock”), certain of the holders of the Company’s Series B-3 Convertible Preferred Stock, par value $0.001 per share (“Series B-3 Preferred Stock”), certain of the
holders of the Company’s Series C-3 Convertible Preferred Stock, par value $0.001 per share (“Series C-3 Preferred Stock”) and certain of the holders of the Company’s Series D-3 Convertible Preferred Stock, par
value $0.001 per share (“Series D-3 Preferred Stock”), and each of the persons set forth on Schedule B attached to this Amendment (each a “New Investor,” and collectively, the “New
Investors”). Capitalized terms not specifically defined herein shall have the meanings ascribed to them in the Stockholder Agreement (as defined below). 

RECITALS 
 WHEREAS,
the Company, certain of the holders of the Common Stock, Series A-3 Preferred Stock, Series B-3 Preferred Stock, Series C-3 Preferred Stock and Series D-3 Preferred Stock previously entered into the Second Amended and Restated Investor Rights
Agreement, dated August 1, 2007, as amended (the “Investor Rights Agreement”); 
 WHEREAS,
Section 6.8 of the Investor Rights Agreement provides that it may only be amended with the written consent of the party against whom enforcement of such amendment is sought; provided that the consent of the holders of more than 50% of
the Registrable Securities (as defined in the Investor Rights Agreement) is sufficient to bind the holders of Series A-3 Preferred Stock, Series B-3 Preferred Stock, Series C-3 Preferred Stock and Series D-3 Preferred Stock (which
majority must include the holders of a majority of the shares of the Series D-3 Preferred Stock); 
 WHEREAS, pursuant to the
terms of that certain Series E-3 Preferred Stock Purchase Agreement, by and among the Company and the Investors purchasing shares of the Company’s Series E-3 Preferred Stock, par value $0.001 per share (the “Series E-3 Preferred
Stock”) dated on or about the date hereof (the “Purchase Agreement”), certain existing parties to the Investor Rights Agreement and the New Investors shall receive shares of Series E-3 Preferred Stock; 

WHEREAS, as a condition to the closing of the transactions contemplated by the Purchase Agreement and the issuance of the Series E-3
Preferred Stock to the New Investors, each New Investor must execute this Amendment and become a party to the Investor Rights Agreement; and 

WHEREAS, the undersigned, holding the requisite amount of stock necessary to amend the Investor Rights Agreement, desire to amend the
Investor Rights Agreement as provided herein. 
 AGREEMENT 

NOW, THEREFORE, in consideration of the foregoing, the mutual covenants herein contained and other good and valuable
consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows: 
 1. New Investors.
Each New Investor hereby agrees to become a party to the Investor Rights Agreement and to be bound by each and every term thereof. Each of the New Investors listed on 

 
Schedule A attached hereto is hereby added to Exhibit A to the Investor Rights Agreement as a Series E-3 Investor, and each New
Investor shall be deemed an Investor (as such term is defined the Investor Rights Agreement) for all purposes contained in the Investor Rights Agreement. Each holder of Series E-3 Preferred Stock that is already party to the Investor Rights
Agreement shall also be added to Exhibit A to the Investor Rights Agreement as a Series E-3 Investor. 
 2. Amended Provisions. The
Investor Rights Agreement is hereby amended such that: 
 Section 3.1(e) Registrable Securities is hereby replaced in its entirety with
the following: 
 “(e) Registrable Securities. The term “Registrable
Securities” means: (i) all shares of Common Stock held by any Investor, (ii) all shares of Common Stock issued or issuable pursuant to the conversion of the Series A-3 Preferred Stock, Series B-3 Preferred Stock, Series C-3
Preferred Stock, Series D-3 Preferred Stock or Series E-3 Preferred Stock (collectively, the “Preferred Stock”), (iii) all shares of Common Stock issued or issuable pursuant to the exercise of warrants to purchase Common
Stock held by any Investor, (iv) solely for purposes of Section 3.3 hereof, shares of Common Stock held by or issuable upon the exercise of warrants or conversion of Preferred Stock held by certain financial and educational
institutions, and (v) any shares of Common Stock or other securities of the Company issued in connection with any stock split, stock dividend, recapitalization or similar event relating to any of the foregoing;
excluding in all cases, however, any Registrable Securities sold by a person in a transaction in which the rights under this Section 3 are not assigned in accordance with this Agreement or any
Registrable Securities sold to the public or sold pursuant to Rule 144 promulgated under the Securities Act.” 
 The reference to
“Series D-3” in Clause (i) of Section 4.2(a) New Securities is hereby replaced with the term “Series E-3.” 

The references to “at least a majority of the Series D-3 Preferred Stock” in Clause (vi) of Section 4.2(a) New Securities
and in Section 6.8 Amendments and Waivers are hereby replaced with the phrase “at least a majority of each of the Series D-3 Preferred Stock and Series E-3 Preferred Stock.” 

3. Counterparts. This Amendment may be executed in two or more counterparts, each of which shall be deemed an original, but all of
which together shall constitute one and the same instrument. 
 4. Titles and Subtitles. The titles and subtitles used in this
Amendment are used for convenience only and are not to be considered in construing or interpreting this Amendment. 
 5. Entire
Agreement. The Investor Rights Agreement, as modified by this Amendment, and the documents referred to herein and therein constitute the entire agreement among the parties in respect of the subject matter hereof and thereof and no party shall be
liable or bound to any other party in any manner by any warranties, representations or covenants except as specifically set forth herein or therein. 

[Remainder of Page Intentionally Left Blank] 

  
 123 

 IN WITNESS WHEREOF, the undersigned has executed this Amendment as of the date first set forth
above. 
  

			
	COMPANY:
	
	XTERA COMMUNICATIONS, INC.
		
	By:	 	 /s/ Paul J. Colan

	Paul J. Colan
	Chief Financial Officer

 
			
	INVESTORS:
	
	WELLCOME TRUST INVESTMENTS 2 UNLIMITED
		
	By:	 	 /s/ Nick Moakes

		
	Name:	 	 Nick Moakes

		
	Title:	 	 Director

  
 2 

 
			
	INVESTORS:
	
	NEW ENTERPRISE ASSOCIATES 9, L.P.
		
	By:	 	NEA Partners 9, Limited Partnership
		 	Its General Partner
		
	By:	 	 /s/ NEA Partners 9, Limited Partnership

		
	Name:	 	  

		
	Title:	 	  

	
	NEW ENTERPRISE ASSOCIATES 10, L.P.
		
	By:	 	NEA Partners 10, Limited Partnership
		 	Its General Partner
		
	By:	 	 /s/ NEA Partners 10, Limited Partnership

		
	Name:	 	  

		
	Title:	 	  

  
 3 

 
			
	INVESTORS:
	
	ARCH VENTURE FUND III, L.P.
		
	By:	 	ARCH Venture Partners, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Name:	 	 Clinton W. Bybee

	Title:	 	 Managing Director

	
	ARCH VENTURE FUND IV, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Name:	 	 Clinton W. Bybee

	Title:	 	 Managing Director

	
	ARCH VENTURE FUND IVA, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Name:	 	 Clinton W. Bybee

	Title:	 	 Managing Director

	
	ARCH ENTREPRENEURS FUND, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Name:	 	 Clinton W. Bybee

	Title:	 	 Managing Director

	
	ARCH VENTURE FUND VI, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Name:	 	 Clinton W. Bybee

	Title:	 	 Managing Director

  
 4 

 
	
	INVESTORS:
	
	 /s/ Clifford H. Higgerson

	Clifford H. Higgerson

  
 5 

 
	
	INVESTORS:
	
	 /s/ Jon Bayless

	Jon Bayless

  
 6 

 
			
	INVESTORS:
	
	Sevin Rosen Fund VII L.P.
		
	By:	 	SRB Associates VII L.P.
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	 John V. Jaggers

	Title:	 	 General Partner

	
	Sevin Rosen Fund VII Affiliates Fund L.P.
		
	By:	 	SRB Associates VII L.P.
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	 John V. Jaggers

	Title:	 	 General Partner

	
	Sevin Rosen Bayless Management Company
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	 John V. Jaggers

	Title:	 	 Vice President

  
 7 

 
			
	INVESTORS:
	
	Saints Capital Hanover, L.P.
		
	By:	 	Saints Capital VI, LLC
		 	Its General Partner
		
	By:	 	 /s/ David Quinlivan

	Name:	 	 David Quinlivan

	Title:	 	 Managing Member

  
 8 

 
	
	INVESTORS:
	
	 /s/ Jon W. Bayless

	Jon W. Bayless, Separate Property

  
 9 

 
	
	INVESTORS:
	
	 /s/ Jon Hopper

	Jon Hopper

  
 10 

 
			
	INVESTORS:
	
	Estate of Donald W. Brooks
		
	By:	 	 /s/ Jon Hopper

	Name:	 	Jon Hopper
	Title:	 	Executor

  
 11 

 SCHEDULE A 

NEW INVESTORS 
 Catherine Mary Barnes 

Pharus Select Venture Growth, LLC 
 Samih Kawar 

The Kramlich Living Trust U/A/D 6/1/94, C. Richard Kramlich, Trustee 

  
 12EX-4.2

 Exhibit 4.2 

XTERA COMMUNICATIONS, INC. 

AMENDED AND RESTATED VOTING AGREEMENT 

This Amended and Restated Voting Agreement (the “Agreement”) is made as of August 1, 2007, by and among Xtera
Communications, Inc., a Delaware corporation (the “Company”), those certain holders of the Company’s Common Stock set forth on Exhibit A attached to this Agreement (individually, a “Common
Stockholder,” and collectively, the “Common Stockholders”), and the holders of the Series A-1 Convertible Preferred Stock, par value $0.001 per share (“Series A-1 Preferred
Stock”), and the Series B-1 Convertible Preferred Stock, par value $0.001 per share (“Series B-1 Preferred Stock,” and together with the Series A-1 Preferred Stock, the “Preferred
Stock”), of the Company set forth on Exhibit B attached to this Agreement (individually, an “Investor,” collectively, the “Investors,” and together with the Common
Stockholders, the “Stockholders”). 
 RECITALS 

The Company and certain of the Investors are parties to the Series B-1 Preferred Stock Purchase Agreement, dated as of the date of this
Agreement (as amended or otherwise modified from time to time, the “Purchase Agreement”), pursuant to which the Company has agreed to sell, and such Investors have agreed to purchase, shares of Series B-1 Preferred Stock,
subject to certain conditions, including the execution and delivery of this Agreement; 
 The Company, certain Common Stockholders and
certain of the Investors (the “Existing Stockholders”) have previously entered into the Voting Agreement dated as of August 12, 2003 (the “Prior Agreement”); 

The Prior Agreement may be amended, and any provision therein waived, with the consent of the Company, the holders of at least a majority of
the Series A-1 Preferred Stock and the holders of a majority of the Common Stock then outstanding and held by the Existing Stockholders; 

The Company and the Existing Stockholders, as holders of at least a majority of the Series A-1 Preferred Stock and a majority of the
Common Stock then outstanding and held by such Existing Stockholders, desire to amend and restate the Prior Agreement and to accept the rights and obligations created pursuant hereto in lieu of the rights and obligations created under the Prior
Agreement; 
 To induce the Investors to enter into the Purchase Agreement and purchase shares of Series B-1 Preferred Stock
thereunder, the Company, the Common Stockholders and the Investors desire to enter into this Agreement to set forth certain rights and obligations of the Stockholders; 

 NOW, THEREFORE, in consideration of the foregoing recitals and the mutual promises set
forth in this Agreement, the parties to this Agreement agree as follows: 
 1. Certain Definitions. For purposes of this
Agreement, the following terms have the following meanings: 
 (a) an “Affiliate” of an entity shall mean any person
or entity that directly or indirectly, through one or more intermediaries, controls, is controlled by, or is under common control with such entity and with respect to any entity which is a partnership, any partner and affiliated partnership managed
by the same management company or managing general partner or by an entity which controls, is controlled by, or is under common control with such management company or managing general partner. 

(b) “IPO” means the first closing of a bona fide, firm commitment underwritten public offering pursuant to an
effective registration statement under the Securities Act of 1933, as amended, covering the offer and sale of securities for the account of the Corporation to the public (A) at a price per share of Common Stock of not less than $3.46028 per
share (subject to proportionate adjustment in the event of a stock split, reverse stock split, reclassification or stock dividend), (B) with respect to which the Corporation receives aggregate net proceeds (after deduction of underwriting
discounts and commissions) of not less than $75,000,000, and (C) with respect to which such Common Stock is listed for trading on either the New York Stock Exchange or the NASDAQ National Market. 

(c) “On an as-converted basis” means taking into account all of the issued and outstanding shares of Common Stock of
the Company, all issued and outstanding shares of Preferred Stock and other issued and outstanding securities convertible into Common Stock of the Company, each on an as-converted basis. 

(d) “Stock” means and includes all Common Stock and Preferred Stock of the Company (whether already issued or issuable
upon conversion of Preferred Stock). 
 (e) “Transfer” means and includes any sale, assignment, encumbrance,
hypothecation, pledge, conveyance in trust, gift, transfer by bequest, devise or descent, or other transfer or disposition of any kind, including but not limited to transfers to receivers, levying creditors, trustees or receivers in bankruptcy
proceedings, or general assignees for the benefit of creditors, whether voluntary or by operation of law, directly or indirectly, except: 

(i) any transfers of Stock to the Stockholder’s spouse, lineal descendant or antecedent, father, mother, brother or sister of the
Stockholder, the adopted child or adopted grandchild of the Stockholder, or the spouse of any child, adopted child, grandchild or adopted grandchild of the Stockholder, or to a trust or trusts for the exclusive benefit of the Stockholder or the
Stockholder’s family members as listed in this Section 1(g)(i); or 
 (ii) any transfers of Stock to an Affiliate; 

provided that in each and all such cases, (A) the Stockholder shall inform the Company by written notice prior to effecting such permitted transfer of
Stock, and (B) such transferee or Affiliate, as the case may be, shall furnish the Company with an executed counterpart copy of this Agreement and 

  
 -2- 

 
agree to become bound thereby as was the Stockholder. Such transferred Stock shall remain “Stock” hereunder, and the transferee shall be treated as was the Stockholder of such Stock
hereunder, and shall assume all rights and obligations of such Stockholder hereunder. 
 2. Drag-A-Long Rights. 

(a) If, at any time, holders of at least 75% of the then outstanding shares of Preferred Stock, voting together as a single class, vote in
favor of any Liquidation Event as defined in the Amended and Restated Certificate of Incorporation (the “Restated Certificate”) of the Company (an “Approved Sale”), all Stockholders shall consent to
and raise no objections against the Approved Sale, and if the Approved Sale is structured as (A) a merger, share exchange or consolidation of the Company, or a sale of all or substantially all of the assets of the Company or any other form of
corporate reorganization, each Stockholder shall vote all of its Stock and other voting securities of the Company owned or held by such Stockholder in favor of the Approved Sale and shall waive any dissenters rights, appraisal rights or similar
rights in connection with such merger, consolidation or sale, or (B) a sale of all or substantially all of the capital stock of the Company, the Stockholders shall agree to sell all their shares of Common Stock and Preferred Stock which are the
subject of the Approved Sale, on the terms and conditions of such Approved Sale. The Stockholders shall take all necessary and desirable actions in connection with the consummation of the Approved Sale, including the execution of such agreements and
such instruments and other actions reasonably necessary to (1) provide customary representations, warranties, indemnities, and escrow arrangements relating to such Approved Sale and (2) effectuate the allocation and distribution of the
aggregate consideration upon the Approved Sale as set forth in Section 2(b)(i) below. The Stockholders shall be permitted to sell their shares of capital stock pursuant to an Approved Sale without complying with the provisions of
rights of first refusal or co-sale provisions in favor of the Company or the other Stockholders. 
 (b) The obligations of the
Stockholders pursuant to this Section 2 are subject to the satisfaction of the following conditions: 
 (i) upon the
consummation of the Approved Sale, each Stockholder shall receive the same proportion of the aggregate consideration from such Approved Sale that such holder would have received if such aggregate consideration had been distributed by the Company in
complete liquidation pursuant to the rights and preferences set forth in the Restated Certificate as in effect immediately prior to such Approved Sale (giving effect to applicable liquidation preferences); 

(ii) if any Stockholders of a class are given an option as to the form and amount of consideration to be received, all Stockholders of such
class will be given the same option; 
 (iii) no Stockholder shall be obligated to make any out-of-pocket expenditure prior to the
consummation of the Approved Sale (excluding modest expenditures for postage, copies, etc.) and no Stockholder shall be obligated to pay any portion (or shall be entitled to be reimbursed by the Company for that portion paid) that is more than its
pro rata share (based upon the amount of consideration received) of reasonable expenses incurred in connection with a consummated Approved Sale, to the extent such costs are incurred for the benefit of all

  
 -3- 

 
Stockholders, and are not otherwise paid by the Company or the acquiring party (costs incurred by or on behalf of a Stockholder for its sole benefit will not be considered costs of the
transaction hereunder), provided that a Stockholder’s liability for such expenses shall be limited to the total purchase price received by such Stockholder for its shares of capital stock; 

(iv) no Stockholder shall be required to provide any representations, warranties or indemnities (other than pursuant to an escrow of
consideration proportionate to the amount receivable under this Section 2) in connection with the Approved Sale, other than those representations, warranties and indemnities, which indemnities shall be several and not joint, concerning
each Stockholder’s valid ownership of shares of capital stock and stock equivalents, free of all liens and encumbrances (other than those arising under applicable securities laws), provided that a Stockholder’s indemnification obligations
shall be limited to the total purchase price received by such Stockholder for its shares of capital stock, and each Stockholder’s authority, power, and right to enter into and consummate such purchase or merger agreement without violating any
other agreement to which such Stockholder is a party or its assets are bound; and 
 (v) if some or all of the consideration received in
connection with the Approved Sale is other than cash, then the valuation of such assets shall be determined in accordance with Article IV, Section 2(d) of the Restated Certificate. The determination of value shall be final and
binding on all parties. 
 (c) If the Company and any of the Stockholders or their representatives, enter into any negotiation or
transaction for which Rule 506 under the Securities Act of 1933, as amended (the “Securities Act), (or any similar rule then in effect) may be available with respect to such negotiation or transaction (including a merger,
consolidation or other reorganization), each Stockholder who is not an accredited investor (as such term is defined in Rule 501 under the Securities Act) will, at the request of the Company or the Investors, appoint a purchaser representative (as
such term is defined in Rule 501 under the Securities Act) reasonably acceptable to the Company or such Stockholders. 
 3.
Restrictive Legend and Stop Transfer Orders. 
 (a) Legend. Each Stockholder understands and agrees that the Company will
cause the legend set forth below, or a legend substantially equivalent thereto, to be placed upon any certificate(s) or other documents or instruments evidencing ownership of Stock by the Stockholder: 

“THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO A VOTING AGREEMENT ENTERED INTO BY THE HOLDER OF THESE SHARES AND THE COMPANY.
A COPY OF SUCH AGREEMENT IS ON FILE AT THE PRINCIPAL OFFICE OF THE COMPANY. SUCH VOTING AGREEMENT IS BINDING ON CERTAIN TRANSFEREES OF THESE SHARES.” 

(b) Stop Transfer Instructions. Each Stockholder agrees, to ensure compliance with the restrictions referred to herein, that the
Company may issue appropriate “stop transfer” certificates or instructions and that, if the Company transfers its own securities, it may make appropriate notations to the same effect in its records. 

(c) Transfers. No securities shall be Transferred by Stockholder unless (i) such Transfer is made in compliance with all of the
terms of this Agreement and in compliance with the terms of applicable federal and state securities laws and (ii) prior to such Transfer, the Transferee or Transferees sign(s) a counterpart to this Agreement pursuant to which it or they agree
to be bound by the terms of this Agreement. The Company shall not be required (a) to Transfer on its books any shares that shall have been sold or Transferred in violation of any of the provisions of this Agreement or (b) to treat as the
owner of such shares or to accord the right to vote as such owner or to pay dividends to any Transferee to whom such shares shall have been so Transferred. 

  
 -4- 

 4. Termination and Waiver. 

(a) Termination. This Agreement will terminate upon an IPO. 

(b) Waiver. Any waiver by a party of its rights hereunder will be effective only if evidenced by a written instrument executed by such
party or its authorized representative; provided, however, that one or more Investors holding at least a majority of the shares of Common Stock and Preferred Stock (voting together as a single class and not as a separate series, and on an as
converted basis) of the Company held by all Investors may waive any of the rights of all Investors hereunder. 
 5. Miscellaneous
Provisions. 
 (a) Notice. Any notice required or permitted to be given to a party pursuant to the provisions of this
Agreement will be in writing and will be effective on (i) the date of delivery by facsimile, or (ii) the business day after deposit with a nationally-recognized courier or overnight service, including Express Mail, for United States
deliveries or (iii) five (5) business days after deposit in the United States mail by registered or certified mail for United States deliveries. All notices not delivered personally or by facsimile will be sent with postage and other
charges prepaid and properly addressed to the party to be notified at the address set forth below such party’s signature on this Agreement or at such other address as such party may designate by ten (10) days advance written notice to the
other parties hereto. Notwithstanding the foregoing, all notices for delivery outside the United States shall be sent by facsimile (in which case said notice shall be deemed effective as of the next business day following the date of transmission)
or nationally recognized courier (in which case said notice shall be deemed effective as of the fifth day following the date of mailing). Any notice given hereunder to more than one person will be deemed to have been given, for purposes of counting
time periods hereunder, on the date given to the last party required to be given such notice. Notices to the Company will be marked to the attention of the Chief Executive Officer. 

(b) Binding on Successors and Assigns: Inclusion Within Certain Definitions. This Agreement, and the rights and obligations of the
parties hereunder, will inure to the benefit of, and be binding upon, their respective successors, assigns, heirs, executors, administrators and legal representatives. Any permitted Transferee of a Stockholder who is required to become a party
hereto will be considered a “Stockholder” for purposes of this Agreement. 

  
 -5- 

 (c) Severability. If any provision of this Agreement is held to be invalid, illegal or
unenforceable in any respect, such provision will be enforced to the maximum extent possible and such invalidity, illegality or unenforceability will not affect any other provision of this Agreement, and this Agreement will be construed as if such
invalid, illegal or unenforceable provision had (to the extent not enforceable) never been contained herein. 
 (d) Amendment. This
Agreement may be amended only by a written instrument executed by (i) the Company, (ii) the holders of a majority of the shares of Stock held by the Common Holders, and (iii) the holders of a majority, which majority must include the
holders of at least a majority of the Series B-1 Preferred Stock, of the shares of Stock (voting together as a single class and not as a separate series, and on an as converted basis) held by the Investors; provided, however, that in the event such
amendment adversely affects the obligations and/or rights of an Investor in a different manner than the other Investors, such amendment shall also require the written consent of such Investor. 

(e) Governing Law. This Agreement shall be governed in all respects by the laws of the State of Delaware as applied to contracts made
and to be performed entirely within that state between residents of that state. 
 (f) Obligation of Company. The Company and the
Stockholders agree to use their best efforts to enforce the terms of this Agreement, to inform the other Stockholders of any breach hereof (to the extent of the Company’s knowledge thereof) and to assist the Stockholders in the exercise of
their rights thereunder. 
 (g) Counterparts. This Agreement may be executed in any number of counterparts, each of which shall be
deemed an original, and all of which together shall constitute one instrument. 
 (h) Further Assurances. Each party hereby agrees to
execute and deliver all such further instruments and documents and take all such other actions as the other party may reasonably request in order to carry out the intent and purposes of this Agreement. 

(i) Entire Agreement; Successors and Assigns. This Agreement and the exhibits hereto constitute the entire agreement between the
Company and each Investor relative to the subject matter hereof. Any previous agreement between the Company and each Stockholder regarding the subject matter hereof is terminated and superseded by this Agreement. Subject to the exceptions
specifically set forth in this Agreement, the terms and conditions of this Agreement shall inure to the benefit of and be binding upon the respective executors, administrators, heirs, successors and assigns of the parties. 

(j) Conflict. In the event of any conflict between the terms of this Agreement and the Company’s Restated Certificate, or its
Bylaws, the terms of the Company’s Restated Certificate or Bylaws, as the case may be, will control. In the event of any conflict between the terms of this 

  
 -6- 

 
Agreement and any other agreement to which the Stockholder is a party or by which such Stockholder is bound, the terms of this Agreement will control. In the event of any conflict between the
Company’s books and records and this Agreement or any notice delivered hereunder, the Company’s books and records will control absent fraud or error. 

(k) Dispute Resolution. All disputes, claims, or controversies arising out of or relating to this Agreement, or any other agreement
executed and delivered pursuant to this Agreement, or the negotiation, validity or performance hereof and thereof or the transactions contemplated hereby and thereby, that are not resolved by mutual agreement shall be resolved solely and exclusively
by binding arbitration to be conducted before J.A.M.S./Endispute, Inc. or its successor. The parties understand and agree that this arbitration provision shall apply equally to claims of fraud or fraud in the inducement. The arbitration shall be
held in New York, New York before a single arbitrator and shall be conducted in accordance with the rules and regulations promulgated by J.A.M.S./Endispute, Inc. unless specifically modified herein. 

The parties covenant and agree that the arbitration shall commence within one hundred twenty (120) days of the date on which a written
demand for arbitration is filed by any party hereto. In connection with the arbitration proceeding, the arbitrator shall have the power to order the production of documents by each party and any third-party witnesses. In addition, each party may
take up to three depositions as of right, and the arbitrator may in his or her discretion allow additional depositions upon good cause shown by the moving party. However, the arbitrator shall not have the power to order the answering of
interrogatories or the response to requests for admission. In connection with any arbitration, each party shall provide to the other, no later than fourteen (14) business days before the date of the arbitration, the identity of all persons that
may testify at the arbitration, a copy of all documents that may be introduced at the arbitration or considered or used by a party’s witness or expert, and a summary of the expert’s opinions and the basis for said opinions. The
arbitrator’s decision and award shall be made and delivered within sixty (60) days of the conclusion of the arbitration. The arbitrator’s decision shall set forth a reasoned basis for any award of damages or finding of liability. The
arbitrator shall not have power to award damages in excess of actual compensatory damages and shall not multiply actual damages or award punitive damages or any other damages that are specifically excluded under this Agreement, and each party hereby
irrevocably waives any claim to such damages. 
 The parties covenant and agree that they will participate in the arbitration in good faith
and that they will share equally its costs, except as otherwise provided herein. Any party unsuccessfully refusing to comply with an order of the arbitrators shall be liable for costs and expenses, including attorneys’ fees, incurred by the
other party in enforcing the award. This Section 5(k) applies equally to requests for temporary, preliminary or permanent injunctive relief, except that in the case of temporary or preliminary injunctive relief any party may proceed in court
without prior arbitration for the limited purpose of avoiding immediate and irreparable harm. The provisions of this Section 5(k) shall be enforceable in any court of competent jurisdiction. 

Subject to the second sentence of the immediately preceding paragraph, the parties shall bear their own attorneys’ fees, costs and
expenses in connection with the arbitration. The parties will share equally in the fees and expenses charged by J.A.M.S. 

  
 -7- 

 Each of the parties hereto irrevocably and unconditionally consents to the exclusive jurisdiction
of J.A.M.S./Endispute, Inc. to resolve all disputes, claims or controversies arising out of or relating to this Agreement or any other agreement executed and delivered pursuant to this Agreement or the negotiation, validity or performance hereof and
thereof or the transactions contemplated hereby and thereby and further consents to the jurisdiction of the courts of New York, New York for the purposes of enforcing the arbitration provisions of this Section 5(k). Each party further
irrevocably waives any objection to proceeding before J.A.M.S./Endispute, Inc. based upon lack of personal jurisdiction or to the laying of venue and further irrevocably and unconditionally waives and agrees not to make a claim in any court that
arbitration before J.A.M.S./Endispute, Inc. has been brought in an inconvenient forum. Each of the parties hereto hereby consents to service of process by registered mail at the address to which notices are to be given. Each of the parties hereto
agrees that its or his submission to jurisdiction and its or his consent to service of process by mail is made for the express benefit of the other parties hereto. 

(l) Trustee Liability. With respect to its signatory capacity and liability as the trustee of The Wellcome Trust, The Wellcome Trust
Limited (the “Trustee”), enters into this Agreement in its capacity as the trustee for the time being of The Wellcome Trust but not otherwise and it is hereby agreed and declared that notwithstanding anything to the contrary
contained or implied in this Agreement: 
 (i) the obligations incurred by the Trustee under or in consequent of this Agreement shall be
enforceable against it or the other trustees of The Wellcome Trust from time to time; and 
 (ii) the liabilities of the Trustee (or such
other trustees as are referred to in paragraph (a) above) in respect of such obligations shall be limited to such liabilities as can, and may lawfully and properly be met out of the assets of The Wellcome Trust for the time being in the hands
or under the control of the Trustee or such other trustees. 
 (m) Aggregation of Stock. The Stock held by any affiliated entities or
persons of an Investor shall be aggregated with such Investor’s Stock solely for purposes of determining whether or not any right granted hereunder is applicable to such Investor. 

[Remainder of Page Intentionally Left Blank] 

  
 -8- 

 IN WITNESS WHEREOF, the parties hereto have executed this Agreement of the day and year
first above written. 
  

			
	COMPANY:
	
	XTERA COMMUNICATIONS, INC.
		
	By:	 	 /s/ Jon R. Hopper

		 	Jon R. Hopper
		 	President and Chief Executive Officer
		
	Address:	 	500 W. Bethany Drive, Suite 100
		 	Allen, TX 75013

  
 [AMENDED AND RESTATED
VOTING AGREEMENT] 

							
	[signature block for entities]:	 		 	  

		 		 	 (print name of entity)

				
		 		 	By:	 	  

		 		 	Name:	 	  

		 		 	Title:	 	  

			
	[signature block for individuals]	 		 	  

		 		 	 (signature)

				
		 		 	Print Name:	 	  

  
 [AMENDED AND RESTATED
VOTING AGREEMENT] 

 
			
	INVESTORS:
	
	 THE WELLCOME TRUST LIMITED,

AS TRUSTEE OF THE WELLCOME TRUST

		
	By:	 	 /s/ Sandra Robertson

	Name:	 	 Sandra Robertson

	Title:	 	 6 Head of Portfolio Management

	Address:	 	215 Euston Road,
		 	London NW1 2BE,
		 	United Kingdom

  
 [AMENDED AND RESTATED
VOTING AGREEMENT] 

 
			
	INVESTORS:
	
	NEW ENTERPRISE ASSOCIATES 10, L.P.
		
	By:	 	NEA Partners 10, L.P.
		 	Its General Partner
		
	By:	 	 /s/ C. Richard Kramlich

	Name:	 	 C. Richard Kramlich

	Title:	 	 General Partner

	Address:	 	2490 Sand Hill Road
		 	Menlo Park, CA 94025
	
	NEW ENTERPRISE ASSOCIATES 9, L.P.
	By:	 	NEA Partners 9, L.P.
		 	Its General Partner
		
	By:	 	 /s/ C. Richard Kramlich

	Name:	 	 C. Richard Kramlich

	Title:	 	 General Partner

	Address:	 	2490 Sand Hill Road
		 	Menlo Park, CA 94025
	
	NEA VENTURES 2000, L.P.
		
	By:	 	 /s/ Cindy Crnkovich

	Name:	 	 Cindy Crnkovich

	Title:	 	 Vice President

	Address:	 	2490 Sand Hill Road
		 	Menlo Park, CA 94025

  
 [AMENDED AND RESTATED
VOTING AGREEMENT] 

 
			
	INVESTORS:
	
	ARCH VENTURE FUND III, L.P.
		
	By:	 	ARCH Venture Partners, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND IV, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND IVA, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH ENTREPRENEURS FUND, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND VI, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director

  
 [AMENDED AND RESTATED
VOTING AGREEMENT] 

 
			
	INVESTORS:
	
	SEVIN ROSEN FUND VII, L.P.
		
	By:	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240
	
	SEVIN ROSEN VII AFFILIATES FUND, L.P.
		
	By	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240
	
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240

  
 [AMENDED AND RESTATED
VOTING AGREEMENT] 

 
			
	INVESTORS:
	
	COMMUNICATIONS VENTURES IV, L.P.
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	General Partner
		
	Address:	 	505 Hamilton Avenue, Ste. 305
		 	Palo Alto, CA 94301
	
	COMMUNICATIONS VENTURES IV CEO FUND, L.P.
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	General Partner
		
	Address:	 	505 Hamilton Avenue, Ste. 305
		 	Palo Alto, CA 94301
	
	COMMUNICATIONS VENTURES IV ENTREPRENEURS’ FUND, L.P.
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	General Partner
		
	Address:	 	505 Hamilton Avenue, Ste. 305
		 	Palo Alto, CA 94301

  
 [AMENDED AND RESTATED
VOTING AGREEMENT] 

 
					
	INVESTORS:
	
	EDF VENTURES II, LIMITED PARTNERSHIP
		
	By:	 	Enterprise Ventures II, Limited Partnership,
		 	Its General Partner
		
	By:	 	EDM II, Inc.,
		 	Its General Partner
			
		 	By:	 	 /s/ Beau D. Laskey

		 		 	Beau D. Laskey
		 		 	Vice President and Secretary
	
	EDF VENTURES I, LIMITED PARTNERSHIP
		
	By:	 	Enterprise Ventures, Limited Partnership,
		 	Its General Partner
		
	By:	 	EDM, Inc.,
		 	Its General Partner
			
		 	By:	 	 /s/ Beau D. Laskey

		 		 	Beau D. Laskey
		 		 	Vice President and Secretary

  
 [AMENDED AND RESTATED
VOTING AGREEMENT] 

 
			
	INVESTORS:
	
	JON W. BAYLESS, Personal Property
	
	 /s/ Signed by John W. Bayless

	Address:	 	13455 Noel Road, Suite 1670
		 	Two Galleria Tower
		 	Dallas, TX 75240

  
 [AMENDED AND RESTATED
VOTING AGREEMENT] 

 
			
	INVESTORS:
	
	CLIFFORD HIGGERSON
	
	 /s/ Clifford Higgerson

	Address:	 	361 Lytton Ave. 2nd Fl.
		 	Palo Alto, CA 94301

  
 [AMENDED AND RESTATED
VOTING AGREEMENT] 

 EXHIBIT A 

INVESTORS 
 Common Stockholders

 Aether Partners L.P. 

ARCH Entrepreneurs Fund, L.P. 

ARCH Venture Fund III LP 
 ARCH
Venture Fund IV LP 
 Jon Bayless 

Centerpoint Venture Fund III (Q), L.P. 

Centerpoint Venture Fund III, L.P. 

Comventures IV CEO Fund L.P. 

ComVentures IV Entr. Fund L.P. 

ComVentures IV L.P. 
 EDF Ventures
L.P. 
 Patrick Ennis 

Enterprise Dev. Fund II LP 

Deitrich Erdmann 
 Hook
Communications Partners LP 
 Hook Partners V LP 

Infrastructure Co-Invest Fund LP 

Infrastructure Fund L.P. 
 Mohr
Seed Capital II LP 
 New Enterprise Associates 10 L.P. 

New Enterprise Associates 9 L.P. 

Rho Management Trust I 
 Rho
Ventures IV (QP) L.P. 
 Rho Ventures IV GmbH & CO. Beteiligungs KG 

Rho Ventures IV L.P. 
 Sevin Rosen
Fund VII L.P. 
 Sevin Rosen VII Affiliates Fund L.P. 

Star Growth Enterprise, a German Civil Law Partnership (with limitation of liability) 

Star Management of Investments No. II (2000) L.P. 

Star Ventures Managementgesellschaft mbH Nr. 3 & Co. Beteiligungs KG Nr. 3 

SVE Star Ventures Enterprises GmbH & Co. No. IX KG 

SVM Star Ventures Managementgesellschaft mbH Nr. 3 

Thomas A. Kelley & Associates Profit Sharing Plan 

Trellis Partners II L.P. 
 UNC
Investment Fund LLC 
 University of California Berkeley Foundation 

University of Illinois Foundation 

University Technology Investors 

WS Investment 99B 
 Series A-1 Investors

 Access Technology Partners 

James Adox 
 Aether Partners L.P.

 Aaron Alter 

Americanbuoy & Co. 
 ARCH
Entrepreneurs Fund, L.P. 

  
 1 

 ARCH Venture Fund III LP 

ARCH Venture Fund IV LP 
 ARCH
Venture Fund IVA L.P. 
 ARCH Venture Fund VI, L.P. 

Jon Bayless 
 Anand Bellary 

Donald Don Brooks 
 Thomas Brooks

 Centerpoint Venture Fund III (Q), L.P. 

Centerpoint Venture Fund III, L.P. 

Comventures IV CEO Fund L.P. 

ComVentures IV Entr. Fund L.P. 

ComVentures IV L.P. 

Cronus & Co. 
 Current
Ventures II L.P. 
 Dow Chemical Company 

Drutan Investments Ltd. 
 EDF
Ventures L.P. 
 Patrick Ennis 

Enspire Capital Limited 

Enterprise Dev. Fund II LP 

Deitrich Erdmann 
 Fullpath
Nominess Limited 
 Hambrecht & Quist California 

Hayden H. Harris Living Trust DTD 3-6-98 

Clifford Higgerson 
 Hook
Communications Partners LP 
 Hook Partners V LP 

Infrastructure Co-Invest Fund LP 

Infrastructure Fund L.P. 

InterWest Investors Q VIII 

InterWest Investors VII 

InterWest Investors VIII 

InterWest Partners VII 
 InterWest
Partners VIII 
 Anthony Jeffries 

JP Morgan Partners (BHCA) 
 Judith
A. Thompson Living Trust UTA March 12 1998 
 Kummell Investments Limited 

Beau Laskey 
 Mary L. Campbell
Trust 
 Mohr Seed Capital II LP 

New Enterprise Associates 9 L.P. 

New Enterprise Associates 10 L.P. 

Northgate Partners, a Delaware Multiple Series LLC 

Rahn Group 
 Ram Rao 

Sena Reddy 
 Rell Family Partners
Limited 
 Rho Management Trust I 

Rho Ventures IV (QP) L.P. 
 Rho
Ventures IV GmbH & CO. Beteiligungs KG 

  
 2 

 Rho Ventures IV L.P. 

Dave Segre 
 Sevin Rosen Fund VII
L.P. 
 Sevin Rosen VII Affiliates Fund L.P 

Sam Srinivasan 
 Star Growth
Enterprise, a German Civil Law Partnership (with limitation of liability) 
 Star Management of Investments No. II (2000) L.P. 

Star Ventures Managementgesellschaft mbH Nr. 3 & Co. Beteiligungs KG Nr. 3 

Sunny Century LLP 
 SVE Star
Ventures Enterprises SVE Star Ventures Enterprises GmbH & Co. No. IX KG 
 SVM Star Ventures Managementgesellschaft mbH Nr. 3 

John Teegen 
 Thomas A.
Kelley & Associates Profit Sharing Plan 
 Thomas S. Porter Restated Trust dated 7-31-98 

Tose Holdings Limited 
 Trellis
Partners II L.P. 
 UNC Investment Fund LLC 

University of California Berkeley Foundation 

University of Illinois Foundation 

University Technology Investors 

Isaac Vaughn 
 WS Investment 99B

 Series B-1 Investors 
 The Wellcome
Trust Limited, as Trustee of The Wellcome Trust 
 New Enterprise Associates 10, L.P. 

New Enterprise Associates 9, L.P. 

ARCH Venture Fund III, L.P. 
 ARCH
Venture Fund IV, L.P. 
 ARCH Venture Fund IVA, L.P. 

ARCH Entrepreneurs Fund, L.P. 

ARCH Venture Fund VI, L.P. 
 Beau
D. Laskey 
 Clifford Higgerson 

Hayden H. Harris Living Trust DTD 3-6-98 

James R. Adox 
 Northgate
Partners, a Delaware Multiple Series LLC 
 Patrick Ennis 

Thomas S. Porter Restated Trust DTD 11-14-05 

Trellis Partners II, L.P. 
 UC
Berkeley Foundation 
 London Pacific Assurance Limited 

EDF Ventures II, Limited Partnership 

The Infrastructure Fund, LP 
 The
Infrastructure Co-Invest Fund, LP 

  
 3 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 1 TO 

AMENDED AND RESTATED VOTING AGREEMENT 

THIS AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT (this “Amendment”) is made and entered into as of
November 15, 2007 by and among Xtera Communications, Inc., a Delaware corporation (the “Company”), certain of the holders of the Company’s Common Stock, par value $0.001 per share (the “Common
Stock”), certain of the holders of the Company’s Series A-1 Convertible Preferred Stock, par value $0.001 per share (“Series A-1 Preferred Stock”), and certain of the holders of the Company’s
Series B-1 Convertible Preferred Stock, par value $0.001 per share (“Series B-1 Preferred Stock”), all as set forth on Schedule A attached to this Agreement (collectively, the “Consenting
Investors”), and each of the persons set forth on Schedule B attached to this Agreement (each a “New Investor,” and collectively, the “New Investors”). 

RECITALS 
 WHEREAS,
the Company, certain of the holders of the Common Stock and each of the holders of Series A-1 Preferred Stock and Series B-1 Preferred Stock previously entered into that certain Amended and Restated Voting Agreement, dated August 1, 2007 (the
“Voting Agreement”); 
 WHEREAS, pursuant to the terms of that certain Agreement and Plan of Merger dated as
of November 15, 2007 by and among the Company, ANI Acquisition Corp., and Azea Networks, Inc. (the “Merger Agreement”), each New Investor shall receive shares of Series B-1 Preferred Stock (the “New
Shares”); 
 WHEREAS, as a condition to the closing of the transactions contemplated by the Merger Agreement and the
issuance of the New Shares to the New Investors, each New Investor must execute this Amendment and become a party to the Voting Agreement; 

WHEREAS, Section 5(d) of the Voting Agreement provides that it may only be amended by a written instrument executed by the
Company, the holders of a majority of the shares of Common Stock, and the holders of a majority of the shares of the outstanding capital stock of the Company voting together as a single class on an as converted basis (which majority must include the
holders of a majority of the shares of the Series B-1 Preferred Stock); and 
 WHEREAS, the undersigned, holding the requisite amount
of stock necessary to amend the Voting Agreement, desire to amend the Voting Agreement as provided herein. 
 AGREEMENT 

NOW, THEREFORE, in consideration of the foregoing, the mutual covenants herein contained and other good and valuable
consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows: 
 1. New Investors.
Each New Investor hereby agrees to become a party to the Voting Agreement and to be bound by each and every term thereof. Each of the New Investors listed on Schedule B attached hereto is hereby added to Exhibit A to the Voting
Agreement as a Series B-1 Investor, and each New Investor shall be deemed an Investor (as such term is defined the Voting Agreement) for all purposes contained in the Voting Agreement. 

 2. Counterparts. This Amendment may be executed in two or more counterparts, each of which
shall be deemed an original, but all of which together shall constitute one and the same instrument. 
 3. Titles and Subtitles. The
titles and subtitles used in this Amendment are used for convenience only and are not to be considered in construing or interpreting this Amendment. 

4. Entire Agreement. The Voting Agreement, as modified by this Amendment, and the documents referred to herein and therein constitute
the entire agreement among the parties in respect of the subject matter hereof and thereof and no party shall be liable or bound to any other party in any manner by any warranties, representations or covenants except as specifically set forth herein
or therein. 

  
 23 

 IN WITNESS WHEREOF, the undersigned has executed this Amendment as of the date first set
forth above. 
  

			
	COMPANY:
	
	XTERA COMMUNICATIONS, INC.
		
	By:	 	 /s/ Jon R. Hopper

		 	Jon R. Hopper
		 	President and Chief Executive Officer

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	CONSENTING INVESTORS:
	
	THE WELLCOME TRUST LIMITED,
	AS TRUSTEE OF THE WELLCOME TRUST
		
	By:	 	 /s/ Peter Pereira Gray

	Name:	 	 Peter Pereira Gray

	Title:	 	 Deputy CIO

		
	Address:	 	215 Euston Road,
		 	London NW1 2BE,
		 	United Kingdom

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	NEW ENTERPRISE ASSOCIATES 10,
	LIMITED PARTNERSHIP
		
	By:	 	NEA Partners 10, Limited Partners
		 	Its General Partner
		
	By:	 	 /s/ Mark W. Perry

	Name:	 	 Mark W. Perry

	Title:	 	 General Partner

		
	Address:	 	1119 St. Paul Street
		 	Baltimore, MD 21202
	
	NEW ENTERPRISE ASSOCIATES 9,
	LIMITED PARTNERSHIP
		
	By:	 	NEA Partners 9, Limited Partners
		 	Its General Partner
		
	By:	 	 /s/ Mark W. Perry

	Name:	 	 Mark W. Perry

	Title:	 	 General Partner

		
	Address:	 	1119 St. Paul Street
		 	Baltimore, MD 21202
	
	NEA VENTURES 2000, L.P.
		
	By:	 	NEA Partners 9, Limited Partners
		 	Its General Partner
		
	By:	 	 /s/ Mark W. Perry

	Name:	 	 Mark W. Perry

	Title:	 	 General Partner

		
	Address:	 	1119 St. Paul Street
		 	Baltimore, MD 21202

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	ARCH VENTURE FUND III, L.P.
		
	By:	 	ARCH Venture Partners, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND IV, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH ENTREPRENEURS FUND, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND IV A, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND VI, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	SEVIN ROSEN FUND VII, L.P.
		
	By:	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240
	
	SEVIN ROSEN VII AFFILIATES FUND, L.P.
		
	By	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240
	
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	Vice President
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	COMMUNICATIONS VENTURES IV, L.P.
		
	By:	 	ComVen IV, L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	VP and General Counsel
		
	Address:	 	305 Lytton Avenue
		 	Palo Alto, CA 94301
	
	COMMUNICATIONS VENTURES IV CEO FUND, L.P.
		
	By:	 	ComVen IV, L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	VP and General Counsel
		
	Address:	 	305 Lytton Avenue
		 	Palo Alto, CA 94301
	
	COMMUNICATIONS VENTURES IV ENTREPRENEURS’ FUND, L.P.
		
	By:	 	ComVen IV, L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	VP and General Counsel
		
	Address:	 	305 Lytton Avenue
		 	Palo Alto, CA 94301

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	EDF VENTURES II, LIMITED PARTNERSHIP
		
	By:	 	Enterprise Ventures II, Limited Partnership,
		 	Its General Partner
		
	By:	 	EDM II, Inc.,
		 	Its General Partner
		
	By:	 	 /s/ Linda M. Fingerle

		 	Authorized Signatory
	
	EDF VENTURES I, LIMITED PARTNERSHIP
		
	By:	 	Enterprise Ventures, Limited Partnership,
		 	Its General Partner
		
	By:	 	EDM, Inc.,
		 	Its General Partner
		
	By:	 	 /s/ Linda M. Fingerle

		 	Authorized Signatory

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	THE REGENTS OF THE UNIVERSITY OF MICHIGAN
		
	By:	 	 /s/ The Regents of the University of Michigan

		 	Executive Director, University of Michigan
		 	Technology Transfer

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
	
	CLIFFORD H. HIGGERSON
	
	 /s/ Clifford H. Higgerson

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	NEW INVESTORS:
	
	ACCEL EUROPE L.P.
		
	By:	 	Accel Europe Associates L.P.,
		 	Its General Partner
		
	By:	 	Accel Europe Associates L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ Accel Europe L.P.

		 	Attorney in Fact
	
	ACCEL EUROPE INVESTORS 2003 L.P.
		
	By:	 	Accel Europe Associates L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ Accel Europe Associates L.L.C.

		 	Attorney in Fact
		
	Address:	 	Accel Partners
		 	16 St. James St.
		 	London SW1A 1ER, United Kingdom
		 	Phone: 011 44 20 7170 1000
		 	Facsimile: 011 44 20 7170 1099
	
	With a copy to:
		
		 	Richard Zamboldi
		 	Accel Partners
		 	428 University Avenue
		 	Palo Alto, CA 94301
		 	Phone: (650) 614-4800
		 	Facsimile: (650) 614-4880
		 	E-mail: rzamboldi@accel.com

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	ATLAS VENTURE FUND VI, L.P.
	ATLAS VENTURE ENTREPRENEURS’ FUND VI, L.P.
		
	By:	 	Atlas Venture Associates VI, L.P.
		 	their general partner
	By:	 	Atlas Venture Associates VI, Inc.
		 	its general partner
		
	By:	 	 /s/ Jeanne Larkin Henry

		 	Vice President
	
	ATLAS VENTURE FUND VI GMBH & CO. KG
		
	By:	 	Atlas Venture Associates VI, L.P.
		 	its managing limited partner
	By:	 	Atlas Venture Associates VI, Inc.
		 	its general partner
		
	By:	 	 /s/ Jeanne Larkin Henry

		 	Vice President
		
	Address:	 	890 Winter Street
		 	Suite 320
		 	Waltham, MA 02451

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	QUESTER VENTURE PARTNERSHIP
	acting by its general partner
	Quester Venture Managers Ltd
		
	By:	 	 /s/ Sergio Levi

		
	Name:	 	 Sergio Levi

		
	Title:	 	 Director

	
	QUESTER VCT 4 PLC
		
	By:	 	 /s/ Sergio Levi

		
	Name:	 	 Sergio Levi

		
	Title:	 	 Director

	
	QUESTER VCT 5 PLC
		
	By:	 	 /s/ Sergio Levi

		
	Name:	 	 Sergio Levi

		
	Title:	 	 Director

		
	Address:	 	Quester Capital Management Limited
		 	29 Queen Anne’s Gate
		 	London
		 	SW1H 9BU

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	LAGO VENTURES FUND ONE LIMITED
		
	By:	 	 /s/ Daphne Delaney

		
	Name:	 	 Daphne Delaney

		
	Title:	 	 Director

		
	Address:	 	Lyford Manor
		 	West Building, Lyford Cay
		 	PO Box N-7776 (slot 193)
		 	Nassau, Bahamas
	
	With a copy to:
		
		 	Nadim Nsouli
		 	180 Brompton Road
		 	London SW3 1HQ
		 	United Kingdom
	
	CSK-VC SUSTAINABILITY INVESTMENT FUND
	
	By CSK VENTURE CAPITAL CO., LTD.,
	Its Investment Manager
		
	By:	 	 /s/ Shunichi Ishimura

	Name:	 	Shunichi Ishimura
	Title:	 	President & CEO
	
	Address:
	
	5th Fl, Riviera Minami Aoyama Building
	3-3-3 Minami-Aoyama, Minato-ku,
	Tokyo, 107-0062
	JAPAN
	Attn: Alessandro Araldi
	Tel: +81-(0)3-5771-6411
	Fax: +81-(0)3-5771-6412
	E-mail:

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	TVM V INFORMATION TECHNOLOGY GMBH & CO. KG
		
	By:	 	 /s/ John J. Dibello

		
	Name:	 	 John J. Dibello

		
	Title:	 	 Managing Limited Partner

		
	By:	 	 /s/ Mark G. Cipriano

		
	Name:	 	 Mark G. Cipriano

		
	Title:	 	 Managing Limited Partner

			
		
	Address:	 	
		
		 	Christopher Cobbold
		 	TVM Capital
		 	Maximilianstr. 35, Entrance C
		 	D-80539 Munich
		 	Germany
	
	With a copy to:
		
		 	Stefan Fischer
		 	TVM Capital
		 	Maximilianstr. 35, Entrance C
		 	D-80539 Munich
		 	Germany
	
	and to:
		
		 	Mark G. Cipriano
		 	TVM Capital
		 	101 Arch Street, Suite 1950
		 	Boston, MA 02110
		 	USA

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO AMENDED AND RESTATED VOTING AGREEMENT 

 SCHEDULE A 

CONSENTING INVESTORS 
 THE WELLCOME TRUST
LIMITED, AS TRUSTEE OF THE WELLCOME TRUST 
 NEW ENTERPRISE ASSOCIATES 10, L.P. 

NEW ENTERPRISE ASSOCIATES 9, L.P. 
 ARCH VENTURE FUND III, L.P.

 ARCH VENTURE FUND IV, L.P. 
 ARCH ENTREPRENEURS FUND, L.P.

 ARCH VENTURE FUND IV A, L.P. 
 ARCH VENTURE FUND VI, L.P.

 SEVIN ROSEN FUND VII, L.P. 
 SEVIN ROSEN VII AFFILIATES
FUND, L.P. 
 COMMUNICATIONS VENTURES IV, L.P. 

COMMUNICATIONS VENTURES IV CEO FUND, L.P. 
 COMMUNICATIONS
VENTURES IV ENTREPRENEURS’ FUND, L.P. 
 EDF VENTURES II, LIMITED PARTNERSHIP 

EDF VENTURES I, LIMITED PARTNERSHIP 
 REGENTS OF THE UNIVERSITY
OF MICHIGAN 

 SCHEDULE B 

NEW INVESTORS 
 ACCEL EUROPE L.P. 

ACCEL EUROPE INVESTORS 2003 L.P. 
 ATLAS VENTURE FUND VI, L.P.

 ATLAS VENTURE FUND VI GMBH & CO. KG 
 ATLAS
VENTURE ENTREPRENEURS’ FUND VI, L.P. 
 QUESTER VENTURE PARTNERSHIP 

QUESTER VCT 4 PLC 
 QUESTER VCT 5 PLC 

LAGO VENTURES FUND ONE LIMITED 
 TVM V INFORMATION TECHNOLOGY
GMBH & CO. KG 
 CSK-VC SUSTAINABILITY INVESTMENT FUND 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 2 TO 

AMENDED AND RESTATED VOTING AGREEMENT 

THIS AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT (this “Amendment”) is made and
entered into as of March 28, 2008 by and among Xtera Communications, Inc., a Delaware corporation (the “Company”), certain of the holders of the Company’s Common Stock, par value $0.001 per share (the
“Common Stock”), certain of the holders of the Company’s Series A-1 Convertible Preferred Stock, par value $0.001 per share (“Series A-1 Preferred Stock”), and certain
of the holders of the Company’s Series B-1 Convertible Preferred Stock, par value $0.001 per share (“Series B-1 Preferred Stock”), all as set forth on Schedule A attached to this Agreement
(collectively, the “Consenting Investors”), and each of the persons set forth on Schedule B attached to this Agreement (each a “New Investor,” and collectively, the
“New Investors”). 
 RECITALS 

WHEREAS, the Company, certain of the holders of the Common Stock and each of the holders of Series A- I
Preferred Stock and Series B-1 Preferred Stock previously entered into that certain Amended and Restated Voting Agreement, dated August 1, 2007, as amended (the “Voting Agreement”); 

WHEREAS, pursuant to the terms of that certain Agreement and Plan of Merger dated as of March
[    ], 2008 by and among the Company, Meriton Acquisition Corp., and Meriton Networks, Inc. (the “Merger Agreement”), each New Investor shall receive shares of Series B-1 Preferred Stock (the
“New Shares”); 
 WHEREAS, as a condition to the closing of the transactions contemplated by
the Merger Agreement and the issuance of the New Shares to the New Investors, each New Investor must execute this Amendment and become a party to the Voting Agreement; 

WHEREAS, Section 5(d) of the Voting Agreement provides that it may only be amended by a written instrument executed by the
Company, the holders of a majority of the shares of Common Stock, and the holders of a majority of the shares of the outstanding capital stock of the Company voting together as a single class on an as converted basis (which majority must include the
holders of a majority of the shares of the Series B-1 Preferred Stock); and 
 WHEREAS, the undersigned, holding the requisite amount
of stock necessary to amend the Voting Agreement, desire to amend the Voting Agreement as provided herein. 
 AGREEMENT 

NOW, THEREFORE, in consideration of the foregoing, the mutual covenants herein contained and other good and valuable
consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows: 
 1. New
Investors. Each New Investor hereby agrees to become a party to the Voting Agreement and to be bound by each and every term thereof. Each of the New Investors listed on 

 
Schedule B attached hereto is hereby added to Exhibit A to the Voting Agreement as a Series B-1 Investor, and each New Investor shall be deemed an Investor (as such term is defined
the Voting Agreement) for all purposes contained in the Voting Agreement. 
 2. Counterparts. This Amendment may be executed in two
or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. 

3. Titles and Subtitles. The titles and subtitles used in this Amendment are used for convenience only and are not to be considered in
construing or interpreting this Amendment. 
 4. Entire Agreement. The Voting Agreement, as modified by this Amendment, and the
documents referred to herein and therein constitute the entire agreement among the parties in respect of the subject matter hereof and thereof and no party shall be liable or bound to any other party in any manner by any warranties, representations
or covenants except as specifically set forth herein or therein. 

  
 41 

 IN WITNESS WHEREOF, the undersigned has executed this Amendment as of the date first set
forth above. 
  

			
	COMPANY:
	
	XTERA COMMUNICATIONS, INC.
		
	By:	 	 /s/ Paul J. Colan

		 	Paul J. Colan
		 	Chief Financial Officer

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	NEW ENTERPRISE ASSOCIATES 10, LIMITED PARTNERSHIP
		
	By:	 	NEA Partners 10, Limited Partners
		 	Its General Partner
		
	By:	 	 /s/ Charles W. Newhall III

	Name:	 	 Charles W. Newhall III

	Title:	 	 General Partner

		
	Address:	 	1119 St. Paul Street
		 	Baltimore, MD 21202
	
	NEW ENTERPRISE ASSOCIATES 9, LIMITED PARTNERSHIP
		
	By:	 	NEA Partners 9, Limited Partners
		 	Its General Partner
		
	By:	 	 /s/ Charles W. Newhall III

	Name:	 	 Charles W. Newhall III

	Title:	 	 General Partner

		
	Address:	 	1119 St. Paul Street
		 	Baltimore, MD 21202
	
	NEA VENTURES 2000, L.P.
		
	By:	 	 /s/ Pamela J. Clark

	Name:	 	 Pamela J. Clark

	Title:	 	 General Partner

		
	Address:	 	1119 St. Paul Street
		 	Baltimore, MD 21202

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	CSK-VC SUSTAINABILITY INVESTMENT FUND
	
	By CSK VENTURE CAPITAL CO., LTD.,
	Its Investment Manager
		
	By:	 	 /s/ Hiromichi Tabata

	Name:	 	Hiromichi Tabata
	Title:	 	President & CEO
		
	Address:	 	
	
	5th Fl, Riviera Minami Aoyama Building
	3-3-3 Minami-Aoyama, Minato-ku,
	Tokyo, 107-0062
	JAPAN
	Attn: Alessandro Araldi
	Tel: +81-(0)3-5771-6411
	Fax: +81-(0)3-5771-6412
	E-mail:

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	CONSENTING INVESTORS:
	
	THE WELLCOME TRUST LIMITED, AS TRUSTEE OF THE WELLCOME TRUST
		
	By:	 	 /s/ Peter Pereira Gray

	Name:	 	 Peter Pereira Gray

	Title:	 	 Managing Director, Investments

		
	Address:	 	215 Euston Road,
		 	London NW1 2BE,
		 	United Kingdom

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
	
	CLIFFORD H. HIGGERSON
	
	 /s/ Clifford H. Higgerson

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	COMMUNICATIONS VENTURES IV, L.P.
		
	By:	 	ComVen IV, L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	VP and General Counsel
		
	Address:	 	305 Lytton Avenue
		 	Palo Alto, CA 94301
	
	COMMUNICATIONS VENTURES IV CEO FUND, L.P.
		
	By:	 	ComVen IV, L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	VP and General Counsel
		
	Address:	 	305 Lytton Avenue
		 	Palo Alto, CA 94301
	
	COMMUNICATIONS VENTURES IV ENTREPRENEURS’ FUND, L.P.
		
	By:	 	ComVen IV, L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ ComVen IV, LLC

	Title:	 	VP and General Counsel
		
	Address:	 	305 Lytton Avenue
		 	Palo Alto, CA 94301

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	ATLAS VENTURE FUND VI, L.P.
	ATLAS VENTURE ENTREPRENEURS’ FUND VI, L.P.
		
	By:	 	Atlas Venture Associates VI, L.P.
		 	their general partner
	By:	 	Atlas Venture Associates VI, Inc.
		 	its general partner
		
	By:	 	 /s/ Jeanne Larkin Henry

		 	Vice President
	
	ATLAS VENTURE FUND VI GMBH, & Co. KG
		
	By:	 	Atlas Venture Associates VI, L.P.
		 	its managing limited partner
	By:	 	Atlas Venture Associates VI, Inc.
		 	its general partner
		
	By:	 	 /s/ Jeanne Larkin Henry

		 	Vice President
		
	Address:	 	890 Winter Street
		 	Suite 320
		 	Waltham, MA 02451

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	TVM V INFORMATION TECHNOLOGY GMBH & CO. KG
		
	By:	 	 /s/ Edward Braginsky

		
	Name:	 	 Edward Braginsky

		
	Title:	 	 Managing Limited Partner

		
	By:	 	 /s/ Mark G. Cipriano

		
	Name:	 	 Mark G. Cipriano

		
	Title:	 	 Managing Limited Partner

		
	Address:	 	
		
		 	Christopher Cobbold
		 	TVM Capital
		 	Maximilianstr. 35, Entrance C
		 	D-80539 Munich
		 	Germany
	
	With a copy to:
		
		 	Stefan Fischer
		 	TVM Capital
		 	Maximilianstr. 35, Entrance C
		 	D-80539 Munich
		 	Germany
	
	and to:
		
		 	Mark G. Cipriano
		 	TVM Capital
		 	101 Arch Street, Suite 1950
		 	Boston, MA 02110
		 	USA

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	EDF VENTURES II, LIMITED PARTNERSHIP
		
	By:	 	Enterprise Ventures II, Limited Partnership,
		 	Its General Partner
		
	By:	 	EDM II, Inc.,
		 	Its General Partner
		
	By:	 	 /s/ Linda M. Fingerle

		 	Authorized Signatory
	
	EDF VENTURES I, LIMITED PARTNERSHIP
		
	By:	 	Enterprise Ventures, Limited Partnership,
		 	Its General Partner
		
	By:	 	EDM, Inc.,
		 	Its General Partner
		
	By:	 	 /s/ Linda M. Fingerle

		 	Authorized Signatory

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	ACCEL EUROPE L.P.
		
	By:	 	Accel Europe Associates L.P.,
		 	Its General Partner
		
	By:	 	Accel Europe Associates L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ Accel Europe L.P.

		 	Attorney in Fact
	
	ACCEL EUROPE INVESTORS 2003 L.P.
		
	By:	 	Accel Europe Associates L.L.C.
		 	Its General Partner
		
	By:	 	 /s/ Accel Europe Investors 2003 L.P.

		 	Attorney in Fact
		
	Address:	 	Accel Partners
		 	16 St. James St.
		 	London SW1A 1ER, United Kingdom
		 	Phone: 011 44 20 7170 1000
		 	Facsimile: 011 44 20 7170 1099
	
	With a copy to:
		
		 	Richard Zamboldi
		 	Accel Partners
		 	428 University Avenue
		 	Palo Alto, CA 94301
		 	Phone: (650) 614-4800
		 	E-mail: rzamboldi@accel.com

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	ARCH VENTURE FUND III, L.P.
		
	By:	 	ARCH Venture Partners, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND IV, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH ENTREPRENEURS FUND, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND IV A, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director
	
	ARCH VENTURE FUND VI, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Clinton W. Bybee

	Its:	 	Managing Director

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	SEVIN ROSEN FUND VII L.P.
		
	By:	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240
	
	SEVIN ROSEN VII AFFILIATES FUND, L.P.
		
	By:	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240
	
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
		
	Address:	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	QUESTER VENTURE PARTNERSHIP
	acting by its general partner
	Quester Venture Managers Ltd
		
	By:	 	 /s/ Sergio Levi

		
	Name:	 	 Sergio Levi

		
	Title:	 	 Director

	
	QUESTER VCT 4 PLC
		
	By:	 	 /s/ Sergio Levi

		
	Name:	 	 Sergio Levi

		
	Title:	 	 Director

	
	QUESTER VCT 5 PLC
		
	By:	 	 /s/ Sergio Levi

		
	Name:	 	 Sergio Levi

		
	Title:	 	 Director

		
	Address:	 	Quester Capital Management Limited
		 	29 Queen Anne’s Gate
		 	London
		 	SW1H 9BU

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	NEW INVESTORS:
	
	VENTURE COACHES FUND LP
	by its General Partner,
	Venture Coaches Limited
		
	By:	 	 /s/ Claude Haw

	Name:	 	Claude Haw
	Title:	 	President
	Address:	 	555 Legget Dr., Tower B, Suite 830
		 	Kanata, ON K2K 2X3
	Telephone:	 	(613) 271-1500
	Facsimile:	 	(613) 270-1505

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	NEW INVESTORS:
	
	VANTAGEPOINT VENTURE PARTNERS IV (Q), LP
	by VantagePoint Venture Associates IV, LLC
	its General Partner
		
	By:	 	 /s/ Alan E. Salzman

	Name:	 	 Alan E. Salzman

	Title:	 	 Managing Member

			
		 	Address:	 	VantagePoint Venture Partners
		 		 	1001 Bayhill Drive, Suite 300
		 		 	San Bruno, CA 94066
			
		 	Facsimile:	 	
	
	 VANTAGEPOINT VENTURE PARTNERS IV, LP

by VantagePoint Venture Associates IV, LLC
 its General
Partner

		
	By:	 	 /s/ Alan E. Salzman

	Name:	 	 Alan E. Salzman

	Title:	 	 Managing Member

			
		 	Address:	 	VantagePoint Venture Partners
		 		 	1001 Bayhill Drive, Suite 300
		 		 	San Bruno, CA 94066
			
		 	Facsimile:	 	

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	VANTAGEPOINT VENTURE PARTNERS IV PRINCIPALS FUND, LP
	by VantagePoint Venture Associates IV, LLC
	its General Partner
		
	By:	 	 /s/ Alan E. Salzman

	Name:	 	 Alan E. Salzman

	Title:	 	 Managing Member

			
		 	Address:	 	VantagePoint Venture Partners
		 		 	1001 Bayhill Drive, Suite 300
		 		 	San Bruno, CA 94066
			
		 	Facsimile:	 	

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	INVESTORS:
	
	NEWBURY VENTURES III, LP
		
	By:	 	 /s/ David J. Kapnick

		 	Name:	 	David J. Kapnick
		 	Title:	 	Chief Financial Officer
		 	Address:	 	255 Shoreline Drive
		 		 	Suite 520
		 		 	Redwood Shores, CA 94065
		 	Facsimile:	 	(650) 595-2442
	
	NEWBURY VENTURES III GMBH & CO. KG
		
	By:	 	 /s/ David J. Kapnick

		 	Name:	 	David J. Kapnick
		 	Title:	 	Chief Financial Officer
		 	Address:	 	255 Shoreline Drive
		 		 	Suite 520
		 		 	Redwood Shores, CA 94065
		 	Facsimile:	 	(650) 595-2442
	
	NEWBURY VENTURES CAYMAN III, LP
		
	By:	 	 /s/ David J. Kapnick

		 	Name:	 	David J. Kapnick
		 	Title:	 	Chief Financial Officer
		 	Address:	 	255 Shoreline Drive
		 		 	Suite 520
		 		 	Redwood Shores, CA 94065
		 	Facsimile:	 	(650) 595-2442

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	NEWBURY VENTURES EXECUTIVES III, LP
		
	By:	 	 /s/ David J. Kapnick

		 	Name:	 	David J. Kapnick
		 	Title:	 	Chief Financial Officer
		 	Address:	 	255 Shoreline Drive
		 		 	Suite 520
		 		 	Redwood Shores, CA 94065
		 	Facsimile:	 	(650) 595-2442

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	NEW INVESTORS
	
	THE VENGROWTH INVESTMENT FUND INC.
		
	By:	 	 /s/ Patrick DiPietro

		 	Name:	 	Patrick DiPietro
		 	Title:	 	Managing General Partner
		
	By:	 	 /s/ Jay Heller

		 	Name:	 	Jay Heller
		 	Title:	 	General Partner
		 	Address:	 	c/o VenGrowth Capital Management Inc.
		 		 	411 Legget Drive, Suite 705
		 		 	Kanata, Ontario
		 		 	Canada K2K 3C9
		 	Attention:	 	Pat DiPietro
		 	Facsimile:	 	(613) 591-7377
		
		 	With a copy to:
			
		 	Address:	 	c/o VenGrowth Capital Management Inc.
		 		 	105 Adelaide Street,
		 		 	West Suite 1000
		 		 	Toronto, Ontario
		 		 	Canada M5H 1P9
		 	Facsimile:	 	(416) 971-6519

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	NEW INVESTORS
	
	VENGROWTH II INVESTMENT FUND INC.
		
	By:	 	 /s/ Patrick DiPietro

		 	Name:	 	Patrick DiPietro
		 	Title:	 	Managing General Partner
		
	By:	 	 /s/ Jay Heller

		 	Name:	 	Jay Heller
		 	Title:	 	General Partner
		 	Address:	 	c/o VenGrowth Capital Management Inc.
		 		 	411 Legget Drive, Suite 705
		 		 	Kanata, Ontario
		 		 	Canada K2K 3C9
		 		 	Attention: Pat DiPietro
		 	Facsimile:	 	(613) 591-7377
		
		 	With a copy to:
			
		 	Address:	 	c/o VenGrowth Capital Management Inc.
		 		 	105 Adelaide Street,
		 		 	West Suite 1000
		 		 	Toronto, Ontario
		 		 	Canada M5H 1P9
		 		 	Attention: Jay Heller
		 	Facsimile:	 	(416) 971-6519

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	NEW INVESTORS
	
	VENGROWTH III INVESTMENT FUND INC.
		
	By:	 	 /s/ Patrick DiPietro

		 	Name:	 	Patrick DiPietro
		 	Title:	 	Managing General Partner
		
	By:	 	 /s/ Jay Heller

		 	Name:	 	Jay Heller
		 	Title:	 	General Partner
		 	Address:	 	c/o VenGrowth Capital Management Inc.
		 		 	411 Legget Drive, Suite 705
		 		 	Kanata, Ontario
		 		 	Canada K2K 3C9
		 		 	Attention: Pat DiPietro
		 	Facsimile:	 	(613)591-7377255
		
		 	With a copy to:
			
		 	Address:	 	c/o VenGrowth Capital Management Inc.
		 		 	105 Adelaide Street,
		 		 	West Suite 1000
		 		 	Toronto, Ontario
		 		 	Canada M5H 1P9
		 		 	Attention: Jay Heller
		 	Facsimile:	 	(416) 971-6519

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

							
		 		 	NEW INVESTORS:
			
		 		 	KLAUS BUSCH
				
	  
	 		 	By:	 	 /s/ Klaus Busch

	Witness	 		 		 	

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

							
		 		 	NEW INVESTORS:
			
		 		 	MICHAEL PASCOE
				
	  
	 		 	By:	 	 /s/ Michael Pascoe

	Witness	 		 		 	Michael Pascoe

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

									
	INVESTORS:	 		 	
			
	JERUSALEM VENTURE PARTNERS IV, L.P.	 		 	JERUSALEM VENTURE PARTNERS IV-A, L.P.
					
	By:	 	 /s/ Jerusalem Venture Partners IV, LP
	 		 	By:	 	 /s/ Jerusalem Venture Partners IV-A, LP

	Name:	 	  
	 		 	Name:	 	  

	Title:	 	  
	 		 	Title:	 	  

					
	Address:	 	7 West 22nd Street, 7th Floor	 		 	Address:	 	7 West 22nd Street, 7th Floor
		 	New York, NY 10010	 		 		 	New York, NY 10010
			
	JERUSALEM VENTURE PARTNERS ENTREPRENEURS FUND IV, L.P.	 		 	JERUSALEM VENTURE PARTNERS IV (ISRAEL), L.P.
					
	By:	 	 /s/ Jerusalem Venture Partners Entrepreneurs Fund IV, LP
	 		 	By:	 	 /s/ Jerusalem Venture Partners IV (Israel), LP

	Name:	 	  
	 		 	Name:	 	  

	Title:	 	  
	 		 	Title:	 	  

					
	Address:	 	7 West 22nd Street, 7th Floor	 		 	Address:	 	Jerusalem Technology Park, Bldg. 1
		 	New York, NY 10010	 		 		 	Malha, Jerusalem 91487
		 		 		 		 	ISRAEL

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	NEW INVESTORS
	
	DESJARDINS VENTURE CAPITAL, L.P., formerly known as ID, Limited Partnership herein acting by Desjardins Venture Capital Inc.,
	its general partner
		
	By:	 	 /s/ Lue Menard

		 	Name:	 	Lue Menard
		 	Title:	 	Sector Director
		
	By:	 	 /s/ Leon Lajoie

		 	Name:	 	Leon Lajoie
		 	Title:	 	Investement Director
		 	Address:	 	2 Complex e Desjardins
		 		 	Suite 1717
		 		 	Montreal, Quebec
		 		 	Canada H5B 1B8
		 	Facsimile:	 	(514) 281-7808

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO AMENDED AND RESTATED VOTING AGREEMENT 

 SCHEDULE A 

CONSENTING INVESTORS 
 THE WELLCOME TRUST
LIMITED, AS TRUSTEE OF THE WELLCOME TRUST 
 NEW ENTERPRISE ASSOCIATES 10, L.P. 

NEW ENTERPRISE ASSOCIATES 9, L.P. 
 ARCH VENTURE FUND III, L.P.

 ARCH VENTURE FUND IV, L.P. 
 ARCH ENTREPRENEURS FUND, L.P.

 ARCII VENTURE FUND IV A, L.P. 
 ARCH VENTURE FUND VI, L.P.

 SEVIN ROSEN FUND VII, L.P. 
 SEVIN ROSEN VII AFFILIATES
FUND, L.P. 
 COMMUNICATIONS VENTURES IV, L.P. 

COMMUNICATIONS VENTURES IV CEO FUND, L.P. 
 COMMUNICATIONS
VENTURES IV ENTREPRENEURS’ FUND, L.P. 
 EDF VENTURES II, LIMITED PARTNERSHIP 

EDF VENTURES I, LIMITED PARTNERSHIP 
 REGENTS OF THE UNIVERSITY
OF MICHIGAN 
 ACCEL EUROPE L.P. 
 ACCEL EUROPE INVESTORS 2003
L.P. 
 ATLAS VENTURE FUND VI, L.P. 
 ATLAS VENTURE FUND VI
GMBH & CO. KG 
 ATLAS VENTURE ENTREPRENEURS’ FUND VI, L.P. 

QUESTER VENTURE PARTNERSHIP 
 QUESTER VCT 4 PLC 

 QUESTER VCT 5 PLC 

LAGO VENTURES FUND ONE LIMITED 
 TVM V INFORMATION TECHNOLOGY
GMBH & CO. KG 
 CSK-VC SUSTAINABILITY INVESTMENT FUND 

  
 2 

 SCHEDULE B 

NEW INVESTORS 
 VANTAGEPOINT VENTURE
PARTNERS IV (Q), LP 
 VANTAGEPOINT VENTURE PARTNERS IV, LP 

VANTAGEPOINT VENTURE PARTNERS IV PRINCIPALS FUND, LP 
 NEWBURY
VENTURES III, LP 
 NEWBURY VENTURES HI GMBH & Co. KG 

NEWBURY VENTURES CAYMAN HI, LP 
 NEWBURY VENTURES EXECUTIVES
III, LP 
 DESJARDINS VENTURE CAPITAL, L.P. 
 JERUSALEM
VENTURE PARTNERS IV, L.P. 
 JERUSALEM VENTURE PARTNERS IV-A, L.P. 

JERUSALEM VENTURE PARTNERS ENTREPRENEURS FUND IV, L.P. 

JERUSALEM VENTURE PARTNERS IV (ISRAEL), L.P. 
 VENTURE COACHES
FUND LP 
 KLAUS BUSCH 
 MICHAEL PASCOE 

THE VENGROWTH INVESTMENT FUND INC. 
 THE VENGROWTH II INVESTMENT
FUND INC. 
 THE VENGROWTH III INVESTMENT FUND INC. 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 3 TO 

AMENDED AND RESTATED VOTING AGREEMENT 

THIS AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT (this “Amendment”) is made and entered into as of
November 3, 2009 by and among Xtera Communications, Inc., a Delaware corporation (the “Company”), certain of the holders of the Company’s Common Stock, par value $0.001 per share (the “Common
Stock”), certain of the holders of the Company’s Series A-2 Convertible Preferred Stock, par value $0.001 per share (“Series A-2 Preferred Stock”), and certain of the holders of the Company’s
Series B-2 Convertible Preferred Stock, par value $0.001 per share (“Series B-2 Preferred Stock”), all as set forth on Schedule A attached to this Agreement (collectively, the “Consenting
Investors”), and each of the persons set forth on Schedule B attached to this Agreement (each a “New Investor,” and collectively, the “New Investors”). 

RECITALS 
 WHEREAS,
the Company, certain of the holders of the Common Stock, Series A-1 Preferred Stock and Series B-1 Preferred Stock previously entered into that certain Amended and Restated Voting Agreement, dated August 1, 2007, as amended (the
“Voting Agreement”); 
 WHEREAS, Section 5(d) of the Voting Agreement provides that it may only
be amended by a written instrument executed by the Company, the holders of a majority of the shares of Common Stock, and the holders of a majority of the shares of the outstanding capital stock of the Company voting together as a single class on an
as converted basis (which majority must include the holders of a majority of the shares of the Series B-1 Preferred Stock); 

WHEREAS, pursuant to the terms of that certain Note and Warrant Purchase Agreement dated May 5, 2009, participating Investors
exchanged their shares of Series A-1 Preferred Stock and Series B-1 Preferred Stock for shares of Series A-2 Preferred Stock and Series B-2 Preferred Stock; 

WHEREAS, pursuant to the Amended and Restated Certificate of Incorporation of the Company as filed with the Delaware Secretary of State
on May 5, 2009, each share of Series A-1 Preferred and Series B-1 Preferred outstanding on May 31, 2009 automatically converted into one share of Common Stock; 

WHEREAS, pursuant to the terms of that certain Series C-2 Preferred Stock Purchase Agreement by and among the Company and Investors
purchasing shares of the Company’s Series C-2 Preferred Stock, par value $0.001 per share (the “Series C-2 Preferred Stock”), and dated on or about the date hereof (the “Purchase Agreement”), each
New Investor shall receive shares of Series C-2 Preferred Stock (the “New Shares”); 

WHEREAS, as a condition to the closing of the transactions contemplated by the Purchase Agreement and the issuance of the New Shares to
the New Investors, each New Investor must execute this Amendment and become a party to the Voting Agreement; 
 WHEREAS, the
undersigned, holding the requisite amount of stock necessary to amend the Voting Agreement, desire to amend the Voting Agreement as provided herein. 

 AGREEMENT 

NOW, THEREFORE, in consideration of the foregoing, the mutual covenants herein contained and other good and valuable
consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows: 
 1. New Investors.
Each New Investor hereby agrees to become a party to the Voting Agreement and to be bound by each and every term thereof. Each of the New Investors listed on Schedule B attached hereto is hereby added to Exhibit A to the Voting Agreement as a
Series C-2 Investor, and each New Investor shall be deemed an Investor (as such term is defined the Voting Agreement) for all purposes contained in the Voting Agreement. 

2. Amended Provisions. The Voting Agreement is hereby amended such that: 

The introductory paragraph is hereby replaced in its entirety with the following: 

“This Amended and Restated Voting Agreement (the “Agreement”) is made as of August 1, 2007, by
and among Xtera Communications, Inc., a Delaware corporation (the “Company”), those certain holders of the Company’s Common Stock set forth on Exhibit A attached to this Agreement (individually, a
“Common Stockholder,” and collectively, the “Common Stockholders”), and the holders of the Preferred Stock (as defined herein) of the Company set forth on Exhibit B attached to this
Agreement (individually, an “Investor,” collectively, the “Investors,” and together with the Common Stockholders, the “Stockholders”).” 

The first and fifth Recitals are hereby replaced in their entirety with the following: 

“The Company and certain of the Investors are parties to a Stock Purchase Agreement, (as amended or
otherwise modified from time to time, the “Purchase Agreement”), pursuant to which the Company has agreed to sell, and such Investors have agreed to purchase, shares of a series of Preferred Stock of the Company, subject to
certain conditions, including the execution and delivery of this Agreement;” 
 “To induce the
Investors to enter into the Purchase Agreement and purchase shares of Preferred Stock thereunder, the Company, the Investors desire to enter into this Agreement to set forth certain rights and obligations of the Stockholders;” 

Clause (A) in the first sentence of Section 1(b) “IPO” is hereby deleted. 

Clause (B) in the first sentence of Section 1(b) “IPO” hereby replaced in its entirety with the following: 

“(A) with respect to which the Corporation receives aggregate net proceeds (after deduction of underwriting discounts and commissions) of
not less than $50,000,000” 
 Clause (C) in the first sentence of Section 1(b) “IPO” is hereby relabeled Clause
(B). 
 The following definitions are added to Section 1 Certain Definitions and the numbering of the remaining definitions
shall be adjusted accordingly to maintain the alphabetical ordering of the terms: 
 “(d) “Preferred
Stock” means the Series A-2 Convertible Preferred Stock, Series B-2 Convertible Preferred Stock and Series C-2 Convertible Preferred Stock.” 

  
 71 

 The reference to “Series B-1” in Clause (iii) of Section 5(d) Amendment is
hereby replaced with term “Series C-2.” 
 3. Counterparts. This Amendment may be executed in two or more counterparts,
each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. 
 4. Titles and
Subtitles. The titles and subtitles used in this Amendment are used for convenience only and are not to be considered in construing or interpreting this Amendment. 

5. Entire Agreement. The Voting Agreement, as modified by this Amendment, and the documents referred to herein and therein constitute
the entire agreement among the parties in respect of the subject matter hereof and thereof and no party shall be liable or bound to any other party in any manner by any warranties, representations or covenants except as specifically set forth herein
or therein. 

  
 72 

 IN WITNESS WHEREOF, the undersigned has executed this Amendment as of the date first set
forth above. 
  

			
	COMPANY:
	
	XTERA COMMUNICATIONS, INC.
		
	By:	 	 /s/ Paul J. Colan

		 	Paul J. Colan
		 	Chief Financial Officer

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	THE WELLCOME TRUST LIMITED,
	AS TRUSTEE OF THE WELLCOME TRUST
		
	By:	 	 /s/ Peter Pereira Gray

	Name:	 	 Peter Pereira Gray

	Title:	 	 General Partner

	Address:	 	215 Euston Road,
		 	London NW1 2BE,
		 	United Kingdom

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	NEW ENTERPRISE ASSOCIATES 10, L.P.
		
	By:	 	NEA Partners 10, L.P.
		 	Its General Partner
		
	By:	 	 /s/ Louis S. Citron

	Name:	 	 Louis S. Citron

	Title:	 	 Attorney-In-Fact

	Address:	 	2490 Sand Hill Road
		 	Menlo Park, CA 94025
	
	NEW ENTERPRISE ASSOCIATES 9, L.P.
		
	By:	 	NEA Partners 9, L.P.
		 	Its General Partner
		
	By:	 	 /s/ Louis S. Citron

	Name:	 	 Louis S. Citron

	Title:	 	 Attorney-In-Fact

	Address:	 	2490 Sand Hill Road
		 	Menlo Park, CA 94025

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
		 	INVESTORS:
		
		 	ARCH VENTURE FUND III, L.P.
			
		 	By:	 	ARCH Venture Partners, LLC,
		 		 	Its General Partner
			
		 	By:	 	 /s/ Clinton W. Bybee

		 	Its:	 	Managing Director
		
		 	ARCH VENTURE FUND IV, L.P.
			
		 	By:	 	ARCH Venture Partners IV, LLC,
		 		 	Its General Partner
			
		 	By:	 	 /s/ Clinton W. Bybee

		 	Its:	 	Managing Director
		
		 	ARCH VENTURE FUND IVA, L.P.
			
		 	By:	 	ARCH Venture Partners IV, LLC,
		 		 	Its General Partner
			
		 	By:	 	 /s/ Clinton W. Bybee

		 	Its:	 	Managing Director
		
		 	ARCH ENTREPRENEURS FUND, L.P.
			
		 	By:	 	ARCH Venture Partners IV, LLC,
		 		 	Its General Partner
			
		 	By:	 	 /s/ Clinton W. Bybee

		 	Its:	 	Managing Director
		
		 	ARCH VENTURE FUND VI, L.P.
			
		 	By:	 	ARCH Venture Partners IV, LLC,
		 		 	Its General Partner
			
		 	By:	 	 /s/ Clinton W. Bybee

		 	Its:	 	Managing Director
		
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	THE INFRASTRUCTURE FUND, LP
		
	By:	 	IF MANAGEMENT COMPANY, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Peter Hankin

	Name:	 	Peter Hankin
	Title:	 	Managing Member
		
	Address:	 	2710 Sand Hill Road
		 	Building 3, Suite 255
		 	Menlo Park, CA 94025
	
	THE INFRASTRUCTURE CO-INVEST FUND, LP
		
	By:	 	IF MANAGEMENT COMPANY, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Peter Hankin

	Name:	 	Peter Hankin
	Title:	 	Managing Member
		
	Address:	 	2710 Sand Hill Road
		 	Building 3, Suite 255
		 	Menlo Park, CA 94025

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	TRELLIS PARTNERS II, L.P.
		
	By:	 	Trellis Management II, L.P.,
		 	Its General Partner
		
	By:	 	 /s/ Trellis Partners II, LP

	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	UC BERKELEY FOUNDATION
		
	By:	 	 /s/ Lina Wang

	Name:	 	Lina Wang
	Title:	 	  

		
	Address:	 	2080 Addison, Suite 4200
		 	Berkeley, CA 94720
		
	By:	 	 /s/ Loraine Binion

	Name:	 	Loraine Binion
	Title:	 	Interim Treasurer
		
	Address:	 	2080 Addison, Suite 4200
		 	Berkeley, CA 94720

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	LONDON PACIFIC ASSURANCE LIMITED
		
	By:	 	 /s/ Robert A. Cornman

	Name:	 	Robert A. Cornman
	Title:	 	Director
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	CLIFFORD HIGGERSON
	
	 /s/ Clifford Higgerson

	Address:	 	361 Lytton Avenue, 2nd Floor
		 	Palo Alto, CA 94301

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	 HAYDEN H. HARRIS LIVING TRUST

DTD. 3-6-98

		
	By:	 	 /s/ Hayden Harris

	Name:	 	Hayden Harris
	Title:	 	Trustee
		
	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	BEAU D. LASKEY
	
	 /s/ Beau D. Laskey

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	JAMES R. ADOX
	
	 /s/ James R. Adox

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	PATRICK ENNIS
	
	 /s/ Patrick Ennis

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	 THOMAS S. PORTER RESTATED TRUST

DTD. 11-14-05

		
	By:	 	 /s/ Thomas S. Porter

	Name:	 	Thomas S. Porter
	Title:	 	Trustee
		
	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	ACCEL EUROPE L.P.
		
	By:	 	 /s/ Accel Europe L.P.

	Name:	 	 Accel Europe L.P.

	Title:	 	 Attorney in Fact

	Address:	 	428 University Ave.
		 	Palo Alto, CA 94301-1812
	
	ACCEL EUROPE INVESTORS 2003, L.P.
		
	By:	 	 /s/ Accel Europe Investors 2003, LP

	Name:	 	 Accel Europe Investors 2003, LP

	Title:	 	 Attorney in Fact

	Address:	 	428 University Ave.
		 	Palo Alto, CA 94301-1812

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	JON BAYLESS
	
	 /s/ Jon Bayless

	Address:	 	13455 Noel Road, Suite 1670
		 	Two Galleria Tower
		 	Dallas, TX 75240

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

									
		 	INVESTORS:
			
	JERUSALEM VENTURE PARTNERS IV, LP	 		 	JERUSALEM VENTURE PARTNERS ENTREPRENEURS FUND V, LP
					
	By:	 	 /s/ Jerusalem Venture Partners IV, LP
	 		 	By:	 	 /s/ Jerusalem Venture Partners IV-A, LP

	Name:	 	  
	 		 	Name:	 	  

	Title:	 	  
	 		 	Title:	 	  

	Address:	 	24 Hebron Road	 		 	Address:	 	7 West 22nd Street 7th floor
		 	Jerusalem, Israel 93542	 		 		 	NY, NY 10010
			
	JERUSALEM VENTURE PARTNERS IV-A, LP	 		 	JERUSALEM VENTURE PARTNERS IV (ISRAEL), LP
					
	By:	 	 /s/ Jerusalem Venture Partners Entrepreneurs Fund IV, LP
	 		 	By:	 	 /s/ Jerusalem Venture Partners IV (Israel), LP

	Name:	 	  
	 		 	Name:	 	  

	Title:	 	  
	 		 	Title:	 	  

	Address:	 	7 West 22nd Street 7th floor	 		 	Address:	 	24 Hebron Road
		 	NY, NY 10010	 		 		 	Jerusalem, Israel 93542

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	LAGO VENTURES FUND ONE LIMITED
		
	By:	 	 /s/ Arvind Gulati

	Name:	 	 Arvind Gulati

	Title:	 	 Director Representative

	Address:	 	c/o Tradeinvest Asset Management Ltd.
		 	Lyford Manor, West Building
		 	West Bay Street
		 	Lyford Cay, N. P., The Bahamas

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	DOW CHEMICAL COMPANY
		
	By:	 	 /s/ Dow Chemical Company

	Name:	 	  

	Title:	 	  

	Address:	 	2030 Dow Center
		 	Midland, Michigan 48674

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

									
		 	INVESTORS:
			
	NEWBURY VENTURES III, LP	 		 	NEWBURY VENTURES CAYMAN III, LP
					
	By:	 	 /s/ Newbury Ventures III, LP
	 		 	By:	 	 /s/ Newbury Ventures Cayman III, LP

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 	Address*	 	
			
	NEWBURY VENTURES III GMBH &CO KG	 		 	NEWBURY VENTURES EXECUTIVES III, LP
					
	By:	 	 /s/ Newbury Ventures III GMBH & CO KG
	 		 	By:	 	 /s/ Newbury Ventures Executives III, LP

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 	*Address:	 	  

		 		 		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	QUESTER VENTURE PARTNERSHIP
		
	By:	 	 /s/ Quester Venture Partnership

	Name:	 	  

	Title:	 	  

	Address:	 	33 Glasshouse Street
		 	London W1B 5DG
		 	United Kingdom

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	SPARK VCT 2 plc
		
	By:	 	 /s/ Spark VCT 2 plc

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

									
		 		 	INVESTORS:
			
	STAR GROWTH ENTERPRISE	 		 	STAR VENTURES MANAGEMENTGESELLSCHAFT MBH NR. 3 & CO.
					
	By:	 	 /s/ Star Growth Enterprise
	 		 	By:	 	 /s/ Star Ventures ManagementGesellschaft MBH Nr. 3 & Co.

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 	Address*	 	
			
	STAR MANAGEMENT OF INVESTMENTS NO. II (2000) L.P.	 		 	SVE STAR VENTURES ENTERPRISES
					
	By:	 	 /s/ Star Management of Investments No. II (2000) L.P.
	 		 	By:	 	 /s/ SVE Star Ventures Enterprises

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 	Address*	 	
				
	SVM STAR VENTURES MANAGEMENTGESELLSCHAFT MBH NR. 3	 		 	*Address:	 	  

		 		 		 	  

					
	By:	 	 /s/ SVM Star Ventures ManagementGesellschaft MBH NR. 3
	 		 		 	
					
	Name:	 	  
	 		 		 	
					
	Title:	 	  
	 		 		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	THE RAHN GROUP
		
	By:	 	 /s/ The Rahn Group

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

											
		 		 	INVESTORS:
			
	RHO MANAGEMENT TRUST I	 		 	RHO VENTURES IV GMBH & CO. BETEILIGUNGS KG
						
	By:	 	RHO CAPITAL PARTNERS INC.	 		 		 	By:	 	RHO CAPITAL PARTNERS VERWALTONGS GMBH
					
	By:	 	 /s/ Rho Capital Partners Inc.
	 		 	By:	 	 /s/ Rho Capital Partners Verwaltongs GMBH

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 	Address*	 	
			
	RHO VENTURES IV (QP) L.P.	 		 	RHO VENTURES IV L.P.
						
	By:	 	RHO MANAGEMENT VENTURES, IV, LLC	 		 		 	By:	 	RHO MANAGEMENT VENTURES IV, L.L.C.
					
	By:	 	 /s/ Rho Management Ventures, IV, LLC
	 		 	By:	 	 /s/ Rho Management Ventures IV, LLC

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 	*Address:	 	  

		 		 		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	SEVIN ROSEN FUND VII, L.P.
		
	By:	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
	
	SEVIN ROSEN VII AFFILIATES FUND, L.P.
		
	By:	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
	
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
		
	Address:	 	
		 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	TVM V INFORMATION TECHNOLOGY
	GMBH & CO. KG
		
	By:	 	 /s/ Mark G. Cipriano

	Name:	 	 Mark G. Cipriano

	Title:	 	 Managing Limited Partner

	Address:	 	TVM Capital
		 	101 Arch Street, Suite 1950
		 	Boston, MA 02110

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

									
		 		 	INVESTORS:
			
	VANTAGEPOINT VENTURE PARTNERS IV, LP	 		 	VANTAGEPOINT VENTURE PARTNERS IV PRINCIPALS FUND, LP
					
	By:	 	VANTAGEPOINT VENTURE ASSOCIATES IV, L.L.C.	 		 	By:	 	VANTAGEPOINT VENTURE ASSOCIATES IV, L.L.C.
					
	By:	 	 /s/ VantagePoint Venture Associates IV, LLC
	 		 	By:	 	 /s/ VantagePoint Venture Associates IV, LLC

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	*Address	 		 		 	*Address	 	
				
	VANTAGEPOINT VENTURE PARTNERS IV (Q), LP	 		 		 	
					
	By:	 	VANTAGEPOINT VENTURE ASSOCIATES IV, L.L.C.	 		 	*Address:	 	  

		 	 		 		 	  

					
	By:	 	 /s/ VantagePoint Venture Associates IV, LLC
	 		 		 	
					
	Name:	 	  
	 		 		 	
					
	Title:	 	  
	 		 		 	
	*Address	 		 		 		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	INVESTORS:
		
		 	CENTERPOINT VENTURE FUND III (Q), L.P.
			
		 	By:	 	CENTERPOINT ASSOCIATES III, L.P.
		 		 	CENTERPOINT ASSOCIATES
		 		 	MANAGEMENT III, L.L.C.
			
		 	By:	 	 /s/ CenterPoint Associates III, LP

			
		 	Name:	 	  

			
		 	Title:	 	  

			
		 	Address:	 	  

		 		 	  

		
		 	CENTERPOINT VENTURE FUND III, L.P.
			
		 	By:	 	CENTERPOINT ASSOCIATES III, L.P.
		 		 	CENTERPOINT ASSOCIATES
		 		 	MANAGEMENT III, L.L.C.
			
		 	By:	 	 /s/ CenterPoint Associates III, LP

			
		 	Name:	 	  

			
		 	Title:	 	  

		 	Address:	 	  

		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	INVESTORS:
	
	ANTHONY JEFFRIES
		
		 	 /s/ Anthony Jeffries

		 	Address:	 	  

		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	MOHR SEED CAPITAL II LP
		
	By:	 	 /s/ Mohr Seed Capital II LP

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	RELL FAMILY PARTNERS LIMITED
		
	By:	 	 /s/ Rell Family Partners Limited

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	DAVE SEGRE
	
	 /s/ Dave Segre

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	JOHN TEEGAN
	
	 /s/ John Teegan

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	THOMAS A. KELLEY & ASSOCIATES
	PROFIT SHARING PLAN
		
	By:	 	 /s/ Thomas A. Kelley & Associates Profit Sharing Plan

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	UNIVERSITY OF ILLINOIS
	FOUNDATION
		
	By:	 	 /s/ University of Illinois Foundation

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	WS INVESTMENT 99B
		
	By:	 	 /s/ WS Investment 99B

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	NORTHGATE PARTNERS LLC,
	A DELAWARE MULTIPLE SERIES LLC
		
	By:	 	 /s/ Northgate Partners LLC

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	MARY L. CAMPBELL TRUST
		
	By:	 	EDF Ventures
		 	Its Managing Director
		
	By:	 	 /s/ EDF Ventures

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	MIKE PASCOE
	
	 /s/ Mike Pascoe

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	BERKELEY INTERNATIONAL CAPITAL
		
	By:	 	 /s/ Berkeley International Capital

	Name:	 	  

	Title:	 	  

		
	Address:	 	650 California Street, 26th Floor
		 	San Francisco, CA 94108

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO AMENDED AND RESTATED VOTING AGREEMENT 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 4 TO 

AMENDED AND RESTATED VOTING AGREEMENT 

THIS AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT (this “Amendment”) is made and entered into as of
May 17, 2010 by and among Xtera Communications, Inc., a Delaware corporation (the “Company”), certain of the holders of the Company’s Series A-2 Convertible Preferred Stock, par value $0.001 per share
(“Series A-2 Preferred Stock”), certain of the holders of the Company’s Series B-2 Convertible Preferred Stock, par value $0.001 per share (“Series B-2 Preferred Stock”) and certain of the holders
of the Company’s Series C-2 Convertible Preferred Stock, par value $0.001 per share (“Series C-2 Preferred Stock”), all as set forth on Schedule A attached to this Amendment (collectively, the
“Consenting Investors”), and each of the persons set forth on Schedule B attached to this Amendment (each a “New Investor,” and collectively, the “New Investors”).

 RECITALS 

WHEREAS, the Company, certain of the holders of the Common Stock, Series A-2 Preferred Stock, Series B-2 Preferred Stock and Series C-2
Preferred Stock previously entered into that certain Amended and Restated Voting Agreement, dated August 1, 2007, as amended (the “Voting Agreement”); 

WHEREAS, Section 5(d) of the Voting Agreement provides that it may only be amended by a written instrument executed by the
Company, the holders of a majority of the shares of Common Stock, and the holders of a majority of the shares of the outstanding capital stock of the Company voting together as a single class on an as converted basis (which majority must include the
holders of a majority of the shares of the Series C-2 Preferred Stock); 
 WHEREAS, pursuant to the terms of that certain Share
Purchase Agreement dated May     , 2010 by and among the Company and the shareholders of Polariq Limited, a private limited company duly incorporated and in good standing under the laws of England and Wales (the
“Purchase Agreement”), each New Investor shall receive shares of Series C-2 Preferred Stock (the “New Shares”); 

WHEREAS, as a condition to the closing of the transactions contemplated by the Purchase Agreement and the issuance of the New Shares to
the New Investors, each New Investor must execute this Amendment and become a party to the Investor Rights Agreement; and 
 WHEREAS,
the undersigned, holding the requisite amount of stock necessary to amend the Voting Agreement, desire to amend the Voting Agreement as provided herein. 

AGREEMENT 
 NOW,
THEREFORE, in consideration of the foregoing, the mutual covenants herein contained and other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows: 

1. New Investors. Each New Investor hereby agrees to become a party to the Voting Agreement and to be bound by each and every term
thereof. Each of the New Investors listed on Schedule B attached hereto is hereby added to Exhibit A to the Voting Agreement as a Series C-2 Investor, and each New Investor shall be deemed an Investor (as such term is defined the Voting
Agreement) for all purposes contained in the Voting Agreement. 

 2. Counterparts. This Amendment may be executed in two or more counterparts, each of which
shall be deemed an original, but all of which together shall constitute one and the same instrument. 
 3. Titles and Subtitles. The
titles and subtitles used in this Amendment are used for convenience only and are not to be considered in construing or interpreting this Amendment. 

4. Entire Agreement. The Voting Agreement, as modified by this Amendment, and the documents referred to herein and therein constitute
the entire agreement among the parties in respect of the subject matter hereof and thereof and no party shall be liable or bound to any other party in any manner by any warranties, representations or covenants except as specifically set forth herein
or therein. 

  
 115 

 IN WITNESS WHEREOF, the undersigned has executed this Amendment as of the date first set
forth above. 
  

			
	COMPANY:
	
	XTERA COMMUNICATIONS, INC.
		
	By:	 	 /s/ Paul J. Colan

		 	Paul J. Colan
		 	Chief Financial Officer

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	THE WELLCOME TRUST LIMITED,
	AS TRUSTEE OF THE WELLCOME TRUST
		
	By:	 	 /s/ Peter Pereira Gray

	Name:	 	 Peter Pereira Gray

	Title:	 	 General Partner

		
	Address:	 	215 Euston Road,
		 	London NW1 2BE,
		 	United Kingdom

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	NEW ENTERPRISE ASSOCIATES 10, L.P.
		
	By:	 	NEA Partners 10, L.P.
		 	Its General Partner
		
	By:	 	 /s/ Louis S. Citron

	Name:	 	 Louis S. Citron

	Title:	 	 Attorney-in-Fact

	Address:	 	2490 Sand Hill Road
		 	Menlo Park, CA 94025
	
	NEW ENTERPRISE ASSOCIATES 9, L.P.
		
	By:	 	NEA Partners 9, L.P.
		 	Its General Partner
		
	By:	 	 /s/ Louis S. Citron

	Name:	 	 Louis S. Citron

	Title:	 	 Attorney-in-Fact

	Address:	 	2490 Sand Hill Road
		 	Menlo Park, CA 94025

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
		 	INVESTORS:
		
		 	ARCH VENTURE FUND III, L.P.
			
		 	By:	 	ARCH Venture Partners, LLC,
		 		 	Its General Partner
			
		 	By:	 	 /s/ Clinton W. Bybee

		 	Its:	 	Managing Director
		
		 	ARCH VENTURE FUND IV, L.P.
			
		 	By:	 	ARCH Venture Partners IV, LLC,
		 		 	Its General Partner
			
		 	By:	 	 /s/ Clinton W. Bybee

		 	Its:	 	Managing Director
		
		 	ARCH VENTURE FUND IVA, L.P.
			
		 	By:	 	ARCH Venture Partners IV, LLC,
		 		 	Its General Partner
			
		 	By:	 	 /s/ Clinton W. Bybee

		 	Its:	 	Managing Director
		
		 	ARCH ENTREPRENEURS FUND, L.P.
			
		 	By:	 	ARCH Venture Partners IV, LLC,
		 		 	Its General Partner
			
		 	By:	 	 /s/ Clinton W. Bybee

		 	Its:	 	Managing Director
		
		 	ARCH VENTURE FUND VI, L.P.
			
		 	By:	 	ARCH Venture Partners IV, LLC,
		 		 	Its General Partner
			
		 	By:	 	 /s/ Clinton W. Bybee

		 	Its:	 	Managing Director

  

					
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	THE INFRASTRUCTURE FUND, LP
		
	By:	 	IF MANAGEMENT COMPANY, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Peter Hankin

	Name:	 	Peter Hankin
	Title:	 	Managing Member
		
	Address:	 	2710 Sand Hill Road
		 	Building 3, Suite 255
		 	Menlo Park, CA 94025
	
	THE INFRASTRUCTURE CO-INVEST FUND, LP
		
	By:	 	IF MANAGEMENT COMPANY, LLC,
		 	Its General Partner
		
	By:	 	 /s/ Peter Hankin

	Name:	 	Peter Hankin
	Title:	 	Managing Member
		
	Address:	 	2710 Sand Hill Road
		 	Building 3, Suite 255
		 	Menlo Park, CA 94025

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	TRELLIS PARTNERS II, L.P.
		
	By:	 	Trellis Management II, L.P.,
		 	Its General Partner
		
	By:	 	 /s/ Alexander C. Broeker

	Name:	 	 Alexander C. Broeker

	Title:	 	 General Partner

		
	Address:	 	2600 Via Fortuna, Suite 150
		 	Austin, Texas 78746

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	UC BERKELEY FOUNDATION
		
	By:	 	 /s/ Lina Wang

	Name:	 	Lina Wang
	Title:	 	  

		
	Address:	 	2080 Addison, Suite 4200
		 	Berkeley, CA 94720
		
	By:	 	 /s/ Loraine Binion

	Name:	 	Loraine Binion
	Title:	 	Interim Treasurer
		
	Address:	 	2080 Addison, Suite 4200
		 	Berkeley, CA 94720

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	LONDON PACIFIC ASSURANCE LIMITED
		
	By:	 	 /s/ Robert A. Cornman

	Name:	 	Robert A. Cornman
	Title:	 	Director
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	CLIFFORD HIGGERSON
	
	 /s/ Clifford Higgerson

	Address:	 	361 Lytton Avenue, 2nd Floor
		 	Palo Alto, CA 94301

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	HAYDEN H. HARRIS LIVING TRUST DTD. 3-6-98
		
	By:	 	 /s/ Hayden Harris

	Name:	 	Hayden Harris
	Title:	 	Trustee
		
	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	BEAU D. LASKEY
	
	 /s/ Beau D. Laskey

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	JAMES R. ADOX
	
	 /s/ James R. Adox

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	PATRICK ENNIS
	
	 /s/ Patrick Ennis

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	THOMAS S. PORTER RESTATED TRUST DTD. 11-14-05
		
	By:	 	 /s/ Thomas S. Porter

	Name:	 	Thomas S. Porter
	Title:	 	Trustee
		
	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	ACCEL EUROPE L.P.
		
	By:	 	 /s/ Accel Europe L.P.

	Name:	 	 Accel Europe L.P.

	Title:	 	 Attorney-in-Fact

	Address:	 	428 University Ave.
		 	Palo Alto, CA 94301-1812
	
	ACCEL EUROPE INVESTORS 2003, L.P.
		
	By:	 	 /s/ Accel Europe Investors 2003, LP

	Name:	 	 Accel Europe Investors 2003, LP

	Title:	 	 Attorney-in-Fact

	Address:	 	428 University Ave.
		 	Palo Alto, CA 94301-1812

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	JON BAYLESS
	
	 /s/ Jon Bayless

	Address:	 	13455 Noel Road, Suite 1670
		 	Two Galleria Tower
		 	Dallas, TX 75240

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

									
		 		 	INVESTORS:
			
	JERUSALEM VENTURE PARTNERS IV, LP	 		 	JERUSALEM VENTURE PARTNERS ENTREPRENEURS FUND V, LP
					
	By:	 	 /s/ Jerusalem Venture Partners IV, LP
	 		 	By:	 	 /s/ Jerusalem Venture Partners IV-A, LP

	Name:	 	  
	 		 	Name:	 	  

	Title:	 	  
	 		 	Title:	 	  

	Address:	 	24 Hebron Road	 		 	Address:	 	7 West 22nd Street 7th floor
		 	Jerusalem, Israel 93542	 		 		 	NY, NY 10010

									
			
	JERUSALEM VENTURE PARTNERS IV-A, LP	 		 	JERUSALEM VENTURE PARTNERS IV (ISRAEL), LP
					
	By:	 	 /s/ Jerusalem Venture Partners Entrepreneurs Fund IV, LP
	 		 	By:	 	 /s/ Jerusalem Venture Partners IV (Israel), LP

	Name:	 	  
	 		 	Name:	 	  

	Title:	 	  
	 		 	Title:	 	  

	Address:	 	7 West 22nd Street 7th floor	 		 	Address:	 	24 Hebron Road
		 	NY, NY 10010	 		 		 	Jerusalem, Israel 93542

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	LAGO VENTURES FUND ONE LIMITED
		
	By:	 	 /s/ Arvind Gulati

	Name:	 	 Arvind Gulati

	Title:	 	 Director Representative

	Address:	 	c/o Tradeinvest Asset Management Ltd.
		 	Lyford Manor, West Building
		 	West Bay Street
		 	Lyford Cay, N. P., The Bahamas

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	DOW CHEMICAL COMPANY
		
	By:	 	 /s/ Dow Chemical Company

	Name:	 	  

	Title:	 	  

	Address:	 	2030 Dow Center
		 	Midland, Michigan 48674

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

									
		 		 	INVESTORS:
			
	NEWBURY VENTURES III, LP	 		 	NEWBURY VENTURES CAYMAN III, LP
					
	By:	 	 /s/ Newbury Ventures III, LP
	 		 	By:	 	 /s/ Newbury Ventures Cayman III, LP

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 	Address*	 	
			
	NEWBURY VENTURES III GMBH &CO KG	 		 	NEWBURY VENTURES EXECUTIVES III, LP
					
	By:	 	 /s/ Newbury Ventures III GMBH & CO KG
	 		 	By:	 	 /s/ Newbury Ventures Executives III, LP

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 	*Address:	 	  

		 		 		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	QUESTER VENTURE PARTNERSHIP
		
	By:	 	 /s/ Quester Venture Partnership

	Name:	 	  

	Title:	 	  

	Address:	 	33 Glasshouse Street
		 	London W1B 5DG
		 	United Kingdom

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	SPARK VCT 2 plc
		
	By:	 	 /s/ Spark VCT 2 plc

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

									
		 		 	INVESTORS:
			
	STAR GROWTH ENTERPRISE	 		 	STAR VENTURES MANAGEMENTGESELLSCHAFT MBH NR. 3 & CO.
		 		 		 	
	By:	 	 /s/ Dr. Meir Barel
	 		 	By:	 	 /s/ Dr. Meir Barel

					
	Name:	 	 Dr. Meir Barel
	 		 	Name:	 	 Dr. Meir Barel

					
	Title:	 	 Director
	 		 	Title:	 	 Director

					
	Address*	 		 		 	Address*	 	
			
	STAR MANAGEMENT OF INVESTMENTS NO. II (2000) L.P.	 		 	SVE STAR VENTURES ENTERPRISES
					
	By:	 	 /s/ Dr. Meir Barel
	 		 	By:	 	 /s/ Dr. Meir Barel

					
	Name:	 	 Dr. Meir Barel
	 		 	Name:	 	 Dr. Meir Barel

					
	Title:	 	 Director
	 		 	Title:	 	 Director

					
	Address*	 		 		 	Address*	 	
			
	SVM STAR VENTURES MANAGEMENTGESELLSCHAFT MBH NR. 3	 		 	*Address: c/o SVM Star Ventures Managementgesellschaft mbH Nr. 3 Possartstrasse 9; D-81679 Munich; Germany
					
	By:	 	 /s/ Dr. Meir Barel
	 		 		 	
					
	Name:	 	 Dr. Meir Barel
	 		 		 	
					
	Title:	 	 Director
	 		 		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	THE RAHN GROUP
		
	By:	 	 /s/ The Rahn Group

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

											
		 		 	INVESTORS:
			
	RHO MANAGEMENT TRUST I	 		 	RHO VENTURES IV GMBH & CO. BETEILIGUNGS KG
						
	By:	 	RHO CAPITAL PARTNERS INC.	 		 		 	By:	 	RHO CAPITAL PARTNERS VERWALTONGS GMBH
					
	By:	 	 /s/ Rho Capital Partners Inc.
	 		 	By:	 	 /s/ Rho Capital Partners Verwaltongs GMBH

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 	Address*	 	
			
	RHO VENTURES IV (QP) L.P.	 		 	RHO VENTURES IV L.P.
						
	By:	 	RHO MANAGEMENT VENTURES, IV, LLC	 		 		 	By:	 	RHO MANAGEMENT VENTURES IV, L.L.C.
					
	By:	 	 /s/ Rho Management Ventures, IV, LLC
	 		 	By:	 	 /s/ Rho Management Ventures IV, LLC

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 	*Address:	 	  

		 		 		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	SEVIN ROSEN FUND VII, L.P.
		
	By:	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
	
	SEVIN ROSEN VII AFFILIATES FUND, L.P.
		
	By:	 	SRB ASSOCIATES VII L.P.,
		 	Its General Partner
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
	
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
		
	*Address	 	13455 Noel Rd., Suite 1670
		 	Dallas, TX 75240

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	TVM V INFORMATION TECHNOLOGY GMBH & CO. KG
		
	By:	 	 /s/ Mark G. Cipriano

	Name:	 	 Mark G. Cipriano

	Title:	 	 Managing Limited Partner

	Address:	 	TVM Capital
		 	101 Arch Street, Suite 1950
		 	Boston, MA 02110

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

									
		 		 	INVESTORS:
			
	VANTAGEPOINT VENTURE PARTNERS IV, LP	 		 	VANTAGEPOINT VENTURE PARTNERS IV PRINCIPALS FUND, LP
					
	By:	 	VANTAGEPOINT VENTURE ASSOCIATES IV, L.L.C.	 		 	By:	 	VANTAGEPOINT VENTURE ASSOCIATES IV, L.L.C.
					
	By:	 	 /s/ VantagePoint Venture Associates IV, LLC
	 		 	By:	 	 /s/ VantagePoint Venture Associates IV, LLC

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

	*Address	 		 		 	*Address	 	
				
	VANTAGEPOINT VENTURE PARTNERS IV (Q), LP	 		 		 	

  

									
	By:	 	VANTAGEPOINT VENTURE ASSOCIATES IV, L.L.C.	 		 	*Address:	 	  

		 	 		 		 	  

					
	By:	 	 /s/ VantagePoint Venture Associates IV, LLC
	 		 		 	
					
	Name:	 	  
	 		 		 	
					
	Title:	 	  
	 		 		 	
	*Address	 		 		 		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	INVESTORS:
		
		 	CENTERPOINT VENTURE FUND III (Q), L.P.
			
		 	By:	 	CENTERPOINT ASSOCIATES III,
		 		 	L.P.
		 		 	CENTERPOINT ASSOCIATES MANAGEMENT III, L.L.C.
			
		 	By:	 	 /s/ CenterPoint Associates III, LP

			
		 	Name:	 	  

			
		 	Title:	 	  

			
		 	Address:	 	  

		 		 	  

		
		 	CENTERPOINT VENTURE FUND III, L.P.
			
		 	By:	 	CENTERPOINT ASSOCIATES III, L.P.
		 		 	CENTERPOINT ASSOCIATES MANAGEMENT III, L.L.C.
			
		 	By:	 	 /s/ CenterPoint Associates III, LP

			
		 	Name:	 	  

			
		 	Title:	 	  

		 	Address:	 	  

		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
	INVESTORS:
	
	ANTHONY JEFFRIES
		
		 	 /s/ Anthony Jeffries

		 	Address:	 	  

		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	MOHR SEED CAPITAL II LP
		
	By:	 	 /s/ Mohr Seed Capital II LP

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	RELL FAMILY PARTNERS LIMITED
		
	By:	 	 /s/ Rell Family Partners Limited

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	DAVE SEGRE
	
	 /s/ Dave Segre

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	JOHN TEEGAN
	
	 /s/ John Teegan

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	THOMAS A. KELLEY & ASSOCIATES PROFIT SHARING PLAN
		
	By:	 	 /s/ Thomas A. Kelley & Associates Profit Sharing Plan

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	UNIVERSITY OF ILLINOIS FOUNDATION
		
	By:	 	 /s/ University of Illinois Foundation

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	WS INVESTMENT 99B
		
	By:	 	 /s/ WS Investment 99B

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	NORTHGATE PARTNERS LLC,
	A DELAWARE MULTIPLE SERIES LLC
		
	By:	 	 /s/ Northgate Partners LLC

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	MARY L. CAMPBELL TRUST
		
	By:	 	EDF Ventures
		 	Its Managing Director
		
	By:	 	 /s/ EDF Ventures

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	MIKE PASCOE
	
	 /s/ Mike Pascoe

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	BERKELEY INTERNATIONAL CAPITAL
		
	By:	 	 /s/ Berkeley International Capital

	Name:	 	  

	Title:	 	  

		
	Address:	 	650 California Street, 26th Floor
		 	San Francisco, CA 94108

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	NEW INVESTORS:
	
	Timothy Russell Davison as Trustee under a Declaration of Trust dated 30 April 2010
	
	 /s/ Timothy Russell Davison

	Authorized Signatory,
	Timothy Russell Davison
	
	INDEPENDENT WEALTH MANAGEMENT CONSULTANTS LIMITED
		
	By:	 	 /s/ Timothy Russell Davison

	Name:	 	 T. R. Davison

	Title:	 	  

	
	 /s/ Stuart Barnes

	Stuart Barnes
	
	 /s/ Mike Smith

	Mike Smith
	
	 /s/ Stuart Barnes

	Steve Webb acting by his duly authorized attorney Stuart Barnes
	
	 /s/ Stuart Barnes

	Dave Winterburn acting by his duly authorized attorney Stuart Barnes
	
	 /s/ Stuart Barnes

	John Ellison acting by his duly authorized attorney Stuart Barnes
	
	 /s/ Timothy Russell Davison

	Russell Johnson acting by his duly authorized attorney Timothy Russell Davison
	
	 /s/ Stuart Barnes

	Scott White acting by his duly authorized attorney Stuart Barnes
	
	 /s/ Stuart Barnes

	Steve Desbrulais acting by his duly authorized attorney Stuart Barnes
	
	ASTON UNIVERSITY
		
	By:	 	 /s/ Gareth Evans

	Name:	 	 Gareth Evans

	Title:	 	 Deputy University Secretary

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO AMENDED AND RESTATED VOTING AGREEMENT 

 SCHEDULE B 

NEW INVESTORS 
 Timothy Russell Davison as
Trustee under a Declaration of Trust dated 30 April 2010 
 Timothy Russell Davison 

Independent Wealth Management Consultants Limited 
 Stuart Barnes

 Mike Hamilton-Smith 
 Steve Webb 

Dave Winterburn 
 John Ellison 

Russell Johnson 
 Scott White 

Steve Desbrulais 
 Aston University 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 5 TO 

AMENDED AND RESTATED VOTING AGREEMENT 

THIS AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT (this “Amendment”) is made and entered into as of
September 23, 2011 by and among Xtera Communications, Inc., a Delaware corporation (the “Company”), certain of the holders of the Company’s Series A-2 Convertible Preferred Stock, par value $0.001 per share
(“Series A-2 Preferred Stock”), certain of the holders of the Company’s Series B-2 Convertible Preferred Stock, par value $0.001 per share (“Series B-2 Preferred Stock”) and certain of the holders
of the Company’s Series C-2 Convertible Preferred Stock, par value $0.001 per share (“Series C-2 Preferred Stock”), all as set forth on Schedule A attached to this Amendment (collectively, the
“Consenting Investors”), and each of the persons set forth on Schedule B attached to this Amendment (each a “New Investor,” and collectively, the “New Investors”). 

RECITALS 
 WHEREAS,
the Company, certain of the holders of the Common Stock, Series A-2 Preferred Stock, Series B-2 Preferred Stock and Series C-2 Preferred Stock previously entered into that certain Amended and Restated Voting Agreement, dated August 1, 2007, as
amended (the “Voting Agreement”); 
 WHEREAS, Section 5(d) of the Voting Agreement provides that
it may only be amended by a written instrument executed by the Company, the holders of a majority of the shares of Common Stock, and the holders of a majority of the shares of the outstanding capital stock of the Company voting together as a single
class on an as converted basis (which majority must include the holders of a majority of the shares of the Series C-2 Preferred Stock); 

WHEREAS, pursuant to the terms of that certain Series D-3 Preferred Stock Purchase Agreement, by and among the Company and the
Investors purchasing shares of the Company’s Series D-3 Preferred Stock, par value $0.001 per share (the “Series D-3 Preferred Stock”) dated on or about the date hereof (the “Purchase Agreement”),
participating Investors exchanged their shares of Series A-2 Preferred Stock, Series B-2 Preferred Stock and Series C-2 Preferred Stock for shares of Series A-3 Preferred Stock, Series B-3 Preferred Stock and Series C-3 Preferred Stock; 

WHEREAS, pursuant to the Amended and Restated Certificate of Incorporation of the Company as filed with the Delaware Secretary of State
on September 22, 2011, each share of Series A-2 Preferred Stock, Series B-2 Preferred Stock and Series C-2 Preferred Stock outstanding on September 24, 2011 shall automatically convert into Common Stock; 

WHEREAS, pursuant to the Purchase Agreement, each New Investor shall receive shares of Series D-3 Preferred Stock (the “New
Shares”) 
 WHEREAS, as a condition to the closing of the transactions contemplated by the Purchase Agreement and the
issuance of the New Shares to the New Investors, each New Investor must execute this Amendment and become a party to the Voting Agreement; and 

WHEREAS, the undersigned, holding the requisite amount of stock necessary to amend the Voting Agreement, desire to amend the Voting
Agreement as provided herein. 

 AGREEMENT 

NOW, THEREFORE, in consideration of the foregoing, the mutual covenants herein contained and other good and valuable
consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows: 
 1. New Investors.
Each New Investor hereby agrees to become a party to the Voting Agreement and to be bound by each and every term thereof. Each of the New Investors listed on Schedule B attached hereto is hereby added to Exhibit A to the Voting Agreement as a
Series D-3 Investor, and each New Investor shall be deemed an Investor (as such term is defined the Voting Agreement) for all purposes contained in the Voting Agreement. 

2. Amendment Provisions. The Voting Agreement is hereby amended such that: 

Section 1(d) Preferred Stock is hereby replaced in its entirety with the following: 

“(d) “Preferred Stock” means the Series A-3 Convertible Preferred Stock, Series B-3 Convertible Preferred Stock,
Series C-3 Convertible Preferred Stock and Series D-3 Convertible Preferred Stock.” 
 The reference to “Series C-2” in clause (iii) of
Section 5(d) Amendment is hereby replaced with the term “Series D-3.” 
 All other references to “Series A-2” not
otherwise amended herein are hereby replaced with the term “Series A-3.” 
 All other references to “Series B-2” not otherwise amended
herein are hereby replaced with the term “Series B-3.” 
 All other references to “Series C-2” not otherwise amended herein are hereby
replaced with the term “Series C-3.” 
 3. Counterparts. This Amendment may be executed in two or more counterparts, each
of which shall be deemed an original, but all of which together shall constitute one and the same instrument. 
 4. Titles and
Subtitles. The titles and subtitles used in this Amendment are used for convenience only and are not to be considered in construing or interpreting this Amendment. 

5. Entire Agreement. The Voting Agreement, as modified by this Amendment, and the documents referred to herein and therein constitute
the entire agreement among the parties in respect of the subject matter hereof and thereof and no party shall be liable or bound to any other party in any manner by any warranties, representations or covenants except as specifically set forth herein
or therein. 

  
 160 

 IN WITNESS WHEREOF, the undersigned has executed this Amendment as of the date first set
forth above. 
 COMPANY: 
  

			
	XTERA COMMUNICATIONS, INC.
		
	By:	 	/s/ Paul J. Colan
		 	  Paul J. Colan
		 	  Chief Financial Officer

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	THE WELLCOME TRUST LIMITED,
	AS TRUSTEE OF THE WELLCOME TRUST
		
	By:	 	/s/ Peter Pereira Gray
	Name:	 	Peter Pereira Gray
	Title:	 	Managing Director
		
	Address:	 	215 Euston Road
		 	London NW1 2BE
		 	United Kingdom

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
					
		 	INVESTORS:
		
		 	NEW ENTERPRISE ASSOCIATES 10, L.P.
		
	By:	 	NEA Partners 10, L.P.
		 	Its General Partner
			
		 	By:	 	/s/ Louis S. Citron
		 	Name:	 	Louis S. Citron
		 	Title:	 	Attorney-in-Fact
		 	Address:	 	2490 Sand Hill Road
		 		 	Menlo Park, CA 94025
		
		 	NEW ENTERPRISE ASSOCIATES 9, L.P.
		
	By:	 	NEA Partners 9, L.P.
		 	Its General Partner
			
		 	By:	 	/s/ Louis S. Citron
		 	Name:	 	Louis S. Citron
		 	Title:	 	Attorney-in-Fact
		 	Address:	 	2490 Sand Hill Road
		 		 	Menlo Park, CA 94025

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	ARCH VENTURE FUND III, L.P.
		
	By:	 	ARCH Venture Partners, LLC,
		 	Its General Partner
		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director
	
	ARCH VENTURE FUND IV, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director
	
	ARCH VENTURE FUND IV A, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director
	
	ARCH ENTREPRENEURS FUND, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director
	
	ARCH VENTURE FUND VI, L.P.
		
	By:	 	ARCH Venture Partners IV, LLC,
		 	Its General Partner
		
	By:	 	/s/ Clinton W. Bybee
	Its:	 	Managing Director
		
	Address:	 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	TRELLIS PARTNERS II, L.P.
		
	By:	 	Trellis Management II, L.P.,
		 	Its General Partner
		
	By:	 	/s/ Trellis Management II, L.P.
	Name:	 	 
	Title:	 	 
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	UC BERKELEY FOUNDATION
		
	By:	 	 /s/ Lina Wang

	Name:	 	 Lina Wang

	Title:	 	 
		
	Address:	 	 2080 Addison, Suite 4200

		 	 Berkeley, CA 94720

		
	By:	 	 /s/ Loraine Binion

	Name:	 	 Loraine Binion

	Title:	 	 Interim Treasurer

		
	Address:	 	 2080 Addison, Suite 4200

		 	 Berkeley, CA 94720

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	CLIFFORD HIGGERSON
	
	/s/ Clifford H. Higgerson
	Address:	 	 361 Lytton Avenue, 2nd Floor

		 	 Palo Alto, CA 94301

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	HAYDEN H. HARRIS LIVING TRUST
	DTD. 3-6-98
		
	By:	 	/s/ Hayden Harris
	Name:	 	Hayden Harris
	Title:	 	Trustee
		
	Address:	 	
		 	

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	
	INVESTORS:
	
	BEAU D. LASKEY
	
	/s/ Beau Laskey
	Address:	 	 
		 	

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	
	INVESTORS:
	
	JAMES R. ADOX
	
	/s/ James R. Adox
	Address:	 	
		 	

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	
	INVESTORS:
	
	PATRICK ENNIS
	
	/s/ Patrick Ennis
		
	Address:	 	3150 139th Avenue SE
		 	Building 4
		 	Bellevue, WA 98005

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	
	INVESTORS:
	
	THOMAS S. PORTER RESTATED TRUST
	DTD. 11-14-05
		
	By:	 	/s/ Thomas S. Porter
	Name:	 	Thomas S. Porter
	Title:	 	Trustee
		
	Address:	 	
		 	

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	
	INVESTORS:
	
	ACCEL EUROPE L.P.
		
	By:	 	Accel Europe Associates L.P.
		 	its General Partner
	By:	 	Accel Europe Associates L.L.C.
		 	its General Partner
		
	By:	 	/s/ Accel Europe L.P.
	Name:	 	Accel Europe L.P.
	Title:	 	Attorney in Fact
		
	Address:	 	428 University Ave.
		 	Palo Alto, CA 94301-1812
	
	ACCEL EUROPE INVESTORS 2003, L.P.
		
	By:	 	Accel Europe Investors 2003 L.P.
		 	its General Partner
	By:	 	Accel Europe Associates L.L.C.
		 	its General Partner
		
	By:	 	/s/ Accel Europe Investors 2003 L.P.
	Name:	 	Accel Europe Investors 2003 L.P.
	Title:	 	Attorney in Fact
		
	Address:	 	428 University Ave.
		 	Palo Alto, CA 94301-1812

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	
	INVESTORS:
	
	JON BAYLESS
	
	/s/ Jon Bayless
	Address:	 	13455 Noel Road, Suite 1670
		 	Two Galleria Tower
		 	Dallas, TX 75240

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 INVESTORS: 

 

			
	 JERUSALEM VENTURE PARTNERS IV, LP

 

		
	By:	 	/s/ Jerusalem Venture Partners IV, LP
	Name:	 	 
	Title:	 	 
	Address:	 	24 Hebron Road
		 	Jerusalem, Israel 93542

 

			
	JERUSALEM VENTURE PARTNERS ENTREPRENEURS FUND V, LP
		
	By:	 	/s/ Jerusalem Venture Partners Entrepreneurs Fund V, LP
	Name:	 	 
	Title:	 	 
	Address:	 	7 West 22nd Street 7th floor
	    NY, NY 10010

 
 

 

			
	JERUSALEM VENTURE PARTNERS IV-A, LP
		
	By:	 	/s/ Jerusalem Venture Partners IV-A, LP
	Name:	 	 
	Title:	 	 
	Address:	 	7 West 22nd Street 7th floor
		 	NY, NY 10010

 

			
	JERUSALEM VENTURE PARTNERS IV (ISRAEL), LP
		
	By:	 	/s/ Jerusalem Venture Partners IV (Israel), LP
	Name:	 	 
	Title:	 	 
	Address:	 	24 Hebron Road
	    Jerusalem, Israel 93542

 
 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	
	INVESTORS:
	
	LAGO VENTURES FUND ONE LIMITED
		
	By:	 	/s/ Arvind Gulati
	Name:	 	Arvind Gulati
	Title:	 	Director Representative
	Address:	 	c/o Cayside Trust Company Limited
		 	Lyford Cay House, 6th Floor
		 	Western Road
		 	P.O. Box N-7776 (Slot 193)
		 	Lyford Cay, New Providence
		 	The Bahamas

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 INVESTORS: 

 

			
	
	NEWBURY VENTURES III, LP *
		
	By:	 	/s/ Joseph Kell
		
	Name:	 	Joseph Kell
		
	Title:	 	CFO
		
	Address:	 	255 Shoreline Drive, # 520
		 	Redwood Shores, CA 94065
	
	NEWBURY VENTURES III GMBH &CO, KG **
		
	By:	 	/s/ Joseph Kell
		
	Name:	 	Joseph Kell
		
	Title:	 	CFO
		
	Address:	 	Same

			
	
	NEWBURY VENTURES CAYMAN III, LP *
		
	By:	 	/s/ Joseph Kell
		
	Name:	 	Joseph Kell
		
	Title:	 	CFO
		
	Address:	 	Same
	
	NEWBURY VENTURES EXECUTIVES III, LP *
		
	By:	 	/s/ Joseph Kell
		
	Name:	 	Joseph Kell
		
	Title:	 	CFO
		
	Address:	 	Same

 
 

  

			
		
	*	 	By:         Newbury Venture Partners III, LLC
	  
	 	Its:         General Partner
		
	**	 	By:         Newbury Venture Partners III, LLC
	  
	 	Its:         Managing Limited Partner

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 INVESTORS: 
  

					
	
	Star Growth Enterprise, a German Civil Law Partnership (with limitation of liability)
	By:	 	SVM Star Ventures Managementgesellschaft mbH Nr. 3
	Title:	 	Managing Partner	 	
		
	/s/ Meir Barel	 	
	By:	 	Dr. Meir Barel	 	
	Title:	 	Managing Director	 	
	
	SVM Star Ventures Managementgesellschaft mbH Nr. 3 and Co. Beteiligungs KG Nr. 3
	By:	 	SVM Star Ventures Managementgesellschaft mbH Nr. 3
	Title:	 	Managing Partner	 	
		
	/s/ Meir Barel	 	
	By:	 	Dr. Meir Barel	 	
	Title:	 	Managing Director	 	
	
	SVM Star Ventures Managementgesellschaft mbH Nr. 3
		
	/s/ Meir Barel	 	
	By:	 	Dr. Meir Barel	 	
	Title:	 	Managing Director	 	
	
	SVE Star Ventures Enterprises GmbH & Co. No. IX KG
	By:	 	SVM Star Ventures Managementgesellschaft mbH Nr. 3
	Title:	 	Managing Partner	 	
		
	/s/ Meir Barel	 	
	By:	 	Dr. Meir Barel	 	
	Title:	 	Managing Director	 	
	
	Star Management of Investments No. II (2000) L.P.
	By:	 	SVM STAR Venture Capital Management Ltd.
	Title:	 	Managing Partner	 	
		
	/s/ Meir Barel	 	
	By:	 	Dr. Meir Barel	 	
	Title:	 	Director	 	

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	THE RAHN GROUP
		
	By:	 	/s/ The Rahn Group
	Name:	 	 
	Title:	 	 
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 INVESTORS: 

 

			
	
	RHO MANAGEMENT TRUST I
		
	By:	 	RHO CAPITAL PARTNERS INC.
		
	By:	 	/s/ Jeffrey Martin
		
	Name:	 	Jeffrey Martin
		
	Title:	 	Attorney-in-fact
		
	Address*	 	
	
	RHO VENTURES IV (QP) L.P.
		
	By:	 	RHO MANAGEMENT VENTURES, IV, LLC
		
	By:	 	/s/ Jeffrey Martin
		
	Name:	 	Jeffrey Martin
		
	Title:	 	Attorney-in-fact
		
	Address*	 	

			
	
	RHO VENTURES IV GMBH & CO. BETEILIGUNGS KG
		
	By:	 	RHO CAPITAL PARTNERS VERWALTONGS GMBH
		
	By:	 	/s/ Jeffrey Martin
		
	Name:	 	Jeffrey Martin
		
	Title:	 	Attorney-in-fact
		
	Address*	 	
	
	RHO VENTURES IV L.P.
		
	By:	 	RHO MANAGEMENT VENTURES IV, L.L.C.
		
	By:	 	/s/ Jeffrey Martin
		
	Name:	 	Jeffrey Martin
		
	Title:	 	Attorney-in-fact
		
	*Address:	 	 
		 	 

 
 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	
	INVESTORS:
	
	SEVIN ROSEN FUND VII, L.P.
	
	SRB ASSOCIATES VII L.P.
	Its General Partner
		
	By:	 	/s/ John V. Jaggers
	Name:	 	John V. Jaggers
	Title:	 	General Partner
	Address:	 	    c/o Sevin Rosen Funds
		 	    13455 Noel Road, Suite 1670
		 	    Dallas, TX 75240
	
	SEVIN ROSEN VII AFFILIATES FUND, L.P.
		
	By:	 	SRB ASSOCIATES VII L.P..
		 	Its General Partner
		
	By:	 	/s/ John V. Jaggers
	Name:	 	John V. Jaggers
	Title:	 	General Partner
	Address:	 	    c/o Sevin Rosen Funds
		 	    13455 Noel Road, Suite 1670
		 	    Dallas, TX 75240
	
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	/s/ John V. Jaggers
	Name:	 	John V. Jaggers
	Title:	 	Vice President
	Address:	 	    c/o Sevin Rosen Funds
		 	    13455 Noel Road, Suite 1670
		 	    Dallas, TX 75240

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 INVESTORS: 

 

			
	VANTAGEPOINT VENTURE PARTNERS
IV, LP
		
	By:	 	VANTAGEPOINT VENTURE ASSOCIATES IV, L.L.C.
		
	By:	 	/s/ Vantagepoint Venture Associates IV, L.L.C.
		
	Name:	 	 
		
	Title:	 	 
	*Address
	
	VANTAGEPOINT VENTURE PARTNERS
IV (Q), LP
		
	By:	 	VANTAGEPOINT VENTURE ASSOCIATES IV, L.L.C.
		
	By:	 	/s/ Vantagepoint Venture Associates IV, L.L.C.
		
	Name:	 	 
		
	Title:	 	 
	*Address

 

			
	VANTAGEPOINT VENTURE PARTNERS
IV PRINCIPALS FUND, LP
		
	By:	 	VANTAGEPOINT VENTURE ASSOCIATES IV, L.L.C.
		
	By:	 	/s/ Vantagepoint Venture Associates IV, L.L.C.
		
	Name:	 	 
		
	Title:	 	 
	*Address
	
	
	
		
	  
 *Address:
	 	 
		 	 

 
 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	ANTHONY JEFFRIES
	
	 /s/ Anthony Jeffries

	 Address:
	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	MOHR SEED CAPITAL II LP
		
	By:	 	/s/ Robert Mohr
	Name:	 	Robert Mohr
	Title:	 	Owner
		
	Address:	 	14643 Dallas Parkway, Suite 1000
		 	Dallas, TX 75254

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	RELL FAMILY PARTNERS LIMITED
		
	By:	 	/s/ Rell Family Partners Limited
	Name:	 	 
	Title:	 	 
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	DAVE SEGRE
	
	 /s/ Dave Segre

	 Address:
	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	JOHN TEEGEN
	
	 /s/ John Teegen

	 Address:
	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	THOMAS A. KELLEY & ASSOCIATES
	PROFIT SHARING PLAN
		
	By:	 	/s/ Tom A. Kelley
	Name:	 	Tom A. Kelley
	Title:	 	Trustee of Plan
		
	Address:	 	5 Franciscan Ridge
		 	Portola Valley, California
		 	94028-8043

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	 UNIVERSITY OF ILLINOIS

FOUNDATION

		
	By:	 	/s/ Laura A. Vossman
	Name:	 	Laura A. Vossman
	Title:	 	Assistant Treasurer
		
	Address:	 	1305 W. Green St.
		 	Urbana, IL 61801

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	WS INVESTMENT 99B
		
	By:	 	/s/ WS Investment 99B
	Name:	 	 
	Title:	 	 
		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	ARTHUR TRUEGER
	
	/s/ Arthur Trueger
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	 INVESTORS:
  

STUART BARNES

	
	 /s/ Stuart Barnes

		
	Address:	 	 
		 	 
		 	 
		 	 
		 	 
		 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	 INVESTORS:
  

TIMOTHY RUSSELL DAVISON

	
	 /s/ Timothy Russell Davison

		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	 INVESTORS:
  

STEVEN DESBRUSLAIS

	
	 /s/ Steven Desbruslais

		
	Address:	 	 
		 	 
		 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	 INVESTORS:
  

JOHN ELLISON

	
	 /s/ J. Ellison

		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	 INVESTORS:
  

MICHAEL HAMILTON-SMITH

	
	 /s/ Michael Hamilton-Smith

		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	 INVESTORS:
  

INDEPENDENT WEALTH MANAGEMENT CONSULTANTS LIMITED

		
	By:	 	/s/ Timothy Davison
	Name:	 	Timothy Davison
	Title:	 	Director
		
	Address:	 	14 Exchange Street
		 	Retford DN22 6BL

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	 INVESTORS:
  

RUSSELL JOHNSON

	
	 /s/ Russell Johnson

		
	Address:	 	 
		 	 

  
 COUNTERPART SIGNATURE
TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	TIMOTHY RUSSELL DAVISON AS TRUSTEE UNDER A DECLARATION OF TRUST DATED 30 APRIL 2010
		
	By:	 	/s/ Timothy Davison
	Name:	 	Timothy Davison
	Title:	 	Trustee
		
	Address:	 	14 Exchange Street
		 	Retford DN22 6BL

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	STEPHEN WEBB
	
	/s/ S.M. Webb
	Address:	 	 
		 	 
		 	 

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	SCOTT WHITE
	
	/s/ Scott White
	Address:	 	 
		 	 

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	DAVID WINTERBURN
	
	/s/ David Winterburn
	Address:	 	 
		 	 
		 	 
		 	 
		 	 

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	JEANNE ANN BAYLESS
	
	/s/ Jeanne Ann Bayless
	Address:	 	 
		 	 

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	JON W. BAYLESS, JR.
	
	/s/ Jon W. Bayless, Jr.
	Address:	 	 
		 	 

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	REBECCA L.R. BAYLESS
	
	/s/ Rebecca L.R. Bayless
	Address:	 	 
		 	 

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	JON BAYLESS, SEPARATE PROPERTY
	
	/s/ Jon Bayless
	Address:	 	13455 Noel Road, Suite 1670
		 	Two Galleria Tower
		 	Dallas, TX 75240

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	 REBECCA BAYLESS, TRUSTEE FOR

CHRISTIAN A.R. BAYLESS TRUST

	
	/s/ Rebecca Bayless
	Address:	 	 
		 	 

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	 REBECCA BAYLESS, TRUSTEE FOR

W. ANDREW BAYLESS TRUST

	
	/s/ Rebecca Bayless
	Address:	 	 
		 	 

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	HAYDEN HARRIS
	
	/s/ Hayden Harris
	Address:	 	 
		 	 

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT 

 
			
	INVESTORS:
	
	THOMAS S. PORTER RESTATED TRUST
	DTD. 7-31-98
		
	By:	 	/s/ Thomas S. Porter
	Name:	 	Thomas S. Porter
	Title:	 	Trustee
		
	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 5 TO AMENDED AND RESTATED VOTING AGREEMENT

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00250-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00250-of-00352.parquet"}]]