Document:

EX-4.3

 Exhibit 4.3 

XTERA COMMUNICATIONS, INC. 

PREFERRED STOCKHOLDER AGREEMENT 

This Preferred Stockholder Agreement (the “Agreement”) is made as of August 1, 2007, by and among Xtera
Communications, Inc., a Delaware corporation (the “Company”), 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 A attached to this Agreement (individually, an “Investor,” collectively, the “Investors”). 

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; 

To induce the Investors to enter into the Purchase Agreement and purchase shares of Series B-1 Preferred Stock thereunder, the Company,
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) “Offered Stock” means all Stock proposed to be Transferred by the
Seller. 
 (d) “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. 

(e) “Right of First Refusal” means the right of first refusal provided to the Company and the Investors in
Section 3 of this Agreement. 
 (f) “Seller” means any Series A-1 Stockholder proposing to Transfer
Stock. 
 (g) “Series A-1 Stockholders” means the holders of the Series A-1 Convertible Preferred Stock.

 (h) “Series B-1 Stockholders” means the holders of the Series B-1 Convertible Preferred Stock. 

(i) “Stock” means and includes all Common Stock and Preferred Stock of the Company (whether already issued or issuable
upon conversion of Preferred Stock). 
 (j) “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 Seller’s spouse, lineal descendant or antecedent, father, mother, brother or sister of the Seller, the
adopted child or adopted grandchild of the Seller, or the spouse of any child, adopted child, grandchild or adopted grandchild of the Seller, or to a trust or trusts for the exclusive benefit of the Seller or the Seller’s family members as
listed in this Section; or 
 (ii) any transfers of Stock to an Affiliate; 

provided that in each and all such cases, (A) the Seller shall inform the Company and each Investor 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 and each Investor with an executed counterpart copy of this Agreement and agree to become bound thereby as was the Seller. Such transferred
Stock shall remain “Stock” hereunder, and the transferee shall be treated as was the Seller of such Stock hereunder, and shall assume all rights and obligations of such Seller hereunder. 

2. Notice of Proposed Transfer. Before any Seller may effect any Transfer of Stock, the Seller must give at the same time to the
Company and to each Investor a written notice signed by the Seller (the “Seller’s Notice”) stating (a) the Seller’s bona fide intention to Transfer such Offered

  
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Stock and the name and address of the proposed transferee (the “Transferee”); (b) the number of shares of the Offered Stock; and (c) the bona fide cash price or,
in reasonable detail, other consideration, per share for which the Seller proposes to Transfer such Offered Stock (the “Offered Price”). Upon the request of the Company or any of such Investors, the Seller will promptly
furnish information to the Company and to the Investors as may be reasonably requested to establish that the offer and Transferee are bona fide. 

3. Right of First Refusal. 

(a) The Right. 
 (i)
Company’s Initial Right. The Company has the right of first refusal to purchase any or all of the Offered Stock, if the Company gives written notice of the exercise of such right to the Seller within fifteen (15) days after the date
of its receipt of the Seller’s Notice to the Company (the “Company’s Refusal Period”). If the Company does not desire to purchase all of the Offered Stock, within ten (10) days after expiration of the
Company’s Refusal Period, the Company will give written notice to each Investor, specifying the number of shares of Offered Stock not subscribed for by the Company through exercise of its Right of First Refusal (the “Company’s
Notice”). 
 (ii) Investors’ Right. If the Company does not desire to purchase any or all of the Offered Stock,
the Investors shall have the right of first refusal to purchase all or none of the Offered Stock; provided, that each such Investor gives written notice of the exercise of such right to the Seller within fifteen (15) days after the date of
mailing or other transmission of the Company’s Notice to such Investor (the “Investors’ Refusal Period”), which notice shall indicate the maximum number of shares of Stock that such Series B-1 Stockholder is
willing to purchase, including the number of shares of Stock it would purchase if one or more other Series B-1 Stockholders do not elect to purchase their Series B-1 Stockholder’s Share. To the extent the aggregate number of shares such
Investors desire to purchase exceeds the Offered Stock available, each such Investor will be entitled to purchase a fraction of the Offered Stock, the numerator of which is the number of shares of Stock (assuming the Conversion of Preferred Stock
into Common Stock) held by such Investor and the denominator of which is the number of shares of Stock (assuming the conversion of Preferred Stock into Common Stock) held by all Investors exercising their Right of First Refusal (and if any shares of
Offered Stock remain unallocated after application of the foregoing, such shares shall be allocated through successive applications thereof). 

Upon the expiration of the Investors’ Refusal Period, the number of shares of Stock to be purchased by each Investor who has elected to
participate in purchasing the Offered Stock (the “Participating Investors”) shall be determined as follows: (i) first, there shall be allocated to each Investor electing to purchase, a number of shares of Stock equal to
the lesser of (A) the number of shares of Stock as to which such Investor accepted as set forth in its respective acceptance notice or (B) such Investor’s Pro Rata Fraction, which shall be equal to the product obtained by multiplying
the total number of shares of Stock not purchased by the Company by a fraction, the numerator of which is the total number of shares of Preferred Stock owned by such Investor, and the denominator of which is the total number of shares of Preferred
Stock held by all Investors, in each case as of the date of the Seller’s Notice, and (ii) second, the balance, if any, not allocated under clause (i) above, shall be allocated to those Investors who within the Investors’

  
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Refusal Period delivered an acceptance notice that set forth a number of shares of Stock that exceeded their respective Pro Rata Fractions, in each case on a pro rata basis in proportion to the
number of shares of Stock held by each such Investor up to the amount of such excess. Within ten (10) days after expiration of the Investors’ Refusal Period (the “Confirmation Period”), the Seller will give written
notice to the Company and the Participating Investors, specifying the aggregate number of shares of Offered Stock that were subscribed for by the Investors (the “Subscribed Offered Stock”) exercising their Rights of First
Refusal (the “Confirmation Notice”). Should the Subscribed Offered Stock not equal or exceed the number of shares of Offered Stock, the Participating Investors may notify the Seller, within ten (10) days after expiration
of the Confirmation Period, of their intent to purchase an amount equal to the difference between (i) the Offered Stock and (ii) the Subscribed Offered Stock (such amount, the “Remaining Offered Stock”). Should the
Participating Investors collectively elect not to purchase an amount equal to the Remaining Offered Stock, the Right of First Refusal under this Agreement shall be deemed to have been waived with respect to the Offered Stock. 

(b) Purchase Price. The purchase price for the Offered Stock to be purchased by the Company or by any Investor exercising its Right of
First Refusal under this Agreement will be the Offered Price, and will be payable as set forth in Section 3(c) hereof. If the Offered Price includes consideration other than cash, the cash equivalent value of the non-cash consideration
will be the fair market value as determined by the Board of Directors of the Company, the holders of a majority the outstanding shares of Series A-1 Stock and the holders of a majority the outstanding shares of Series B-1 Stock, provided that if the
Company and such Investors are unable to reach agreement, then by independent appraisal by an investment banker hired and paid by the Company, but acceptable to such Investors. 

(c) Payment. Payment of the purchase price for the Offered Stock purchased by the Company or by an Investor exercising its Right of
First Refusal will be made within fifteen (15) days after the later of (i) the end of the Company’s Refusal Period, or (ii) the delivery of the Company’s Notice and the end of the Investors’ Refusal Period. Payment of
the purchase price will be made, at the option of the Company or the exercising Investor, (i) in cash (by check or wire transfer at the option of the purchaser), (ii) by cancellation of all or a portion of any outstanding indebtedness of
the Seller to the Company or the Investor, as the case may be, or (iii) by any combination of the foregoing. 
 (d) Rights as an
Investor. If the Company or any Investor exercises its Right of First Refusal to purchase the Offered Stock, then, upon the date the notice of such exercise is given by the Company or any Investor, the Seller will have no further rights as a
holder of the Offered Stock except the right to receive payment for the Offered Stock from the Company or the Investors in accordance with the terms of this Agreement, and the Seller will forthwith cause all certificate(s) evidencing such Offered
Stock to be surrendered for transfer to the Company or the Investor, as the case may be. 
 4. Multiple Series, Classes or Types of
Stock. If the Offered Stock consists of more than one series, class or type of Stock, the Seller has the right to Transfer hereunder each such series, class or type. 

  
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 5. Refusal to Transfer. Any attempt by any Seller to Transfer any Stock in
violation of any provision of this Agreement will be void. The Company will not be required (i) to transfer on its books any Stock that has been sold, gifted or otherwise Transferred in violation of this Agreement, or (ii) to treat as
owner of such Stock, or to accord the right to vote or pay dividends to any purchaser, donee or other Transferee to whom such Stock may have been so Transferred. 

6. Board of Directors; Voting. So long as at least 1,000,000 shares of Preferred Stock (as adjusted for any stock dividends,
combinations or splits with respect to such shares occurring after the date hereof) remain outstanding, each Investor hereby agrees to vote all shares of the Company’s capital stock now or hereafter directly or indirectly owned (of record or
beneficially) by such Investor and otherwise to take such action as shall be necessary to: 
 (a) elect and appoint to the Board of
Directors of the Company the following persons: 
 (i) two (2) individuals designated by the holders of a majority of the outstanding
shares of Series B-1 Preferred Stock (each, a “Series B-1 Director”), voting as a single class, one (1) of which shall be the designee of ARCH Venture Partners (“AVP”) for so long as AVP and its
Affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted for any stock dividends, combinations or splits with respect to such shares occurring after the date hereof), and one (1) of which shall be the
designee of New Enterprise Associates (“NEA”) for so long as NEA and its affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted for any stock dividends, combinations or splits with
respect to such shares occurring after the date hereof); and 
 (ii) three (3) individuals designated by the holders of a majority of
the outstanding shares of Series A-1 Preferred Stock (each, a “Series A-1 Director”), voting as a single class, one (1) of which shall be the designee of Sevin Rosen Fund VII, L.P. (“SRF”) for so
long as SRF and its Affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted for any stock dividends, combinations or splits with respect to such shares occurring after the date hereof), and one (1) of
which shall be the designee of Communications Ventures IV, L.P. (“ComVen”) for so long as ComVen and its affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted for any stock dividends,
combinations or splits with respect to such shares occurring after the date hereof); 
 (iii) one (1) individual designated by the
holders of a majority of the outstanding shares of Common Stock, voting as a class, one (1) of which shall be the then-current Chief Executive Officer of the Company (the “CEO Director”); and 

(iv) one (1) individual designated by mutual agreement of the Series B-1 Directors, the Series A-1 Directors and the CEO Director (the
“Outside Director”); 
 (b) ensure that in the event the number of authorized directors is increased beyond seven
(7), the persons filling any newly-created seats shall be approved by both the holders of a majority of the outstanding Common Stock, voting as a class, and the holders of a majority of the Preferred Stock, voting as a class; 

  
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 (c) allow for The Wellcome Trust (“TWT”) to have an observer attend all
meetings of the Board of Directors for so long as TWT and its Affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted for any stock dividends, combinations or splits with respect to such shares occurring after
the date hereof); and to receive all materials provided to the Board of Directors at the time as such directors; provided that such observer shall first enter into a standard nondisclosure agreement with the Company; 

(d) so long as at least 1,000,000 shares of Preferred Stock (as adjusted for any stock dividends, combinations or splits with respect to such
shares) remain issued and outstanding, each authorized committee of the Board of Directors shall include at least 1 Series B-1 Director; 

(e) ensure that the Board of Directors shall consist of the following persons immediately following the first closing of the Company’s Series B-1 Preferred financing pursuant to the Purchase Agreement: Clinton Bybee (Series B-1 Director), Jon Bayless, who shall be Chairman (SRF designee and Series A-1 Director), Cliff Higgerson
(ComVen designee and Series A-1 Director), Hayden Harris (Series A-1 Director), Jon Hopper (CEO Director) and Tingye Li (Outside Director); 

(f) elect the second Series B-1 Director upon designation of such director by NEA; and 

(g) ensure that the Company shall execute and deliver a Director Indemnification Agreement for the Series B-1 Director designated by NEA in
the form attached as Exhibit I to the Purchase Agreement. 
 7. Restrictive Legend and Stop Transfer Orders. 

(a) Legend. Each Investor understands and agrees that the Company may 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 Investor: 

“THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RIGHTS OF FIRST REFUSAL AND/OR VOTING AGREEMENTS AS SET FORTH IN AN
AMENDED AND RESTATED STOCKHOLDER 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 RIGHTS OF FIRST REFUSAL AND VOTING AGREEMENTS ARE BINDING ON
CERTAIN TRANSFEREES OF THESE SHARES.” 
 (b) Stop Transfer Instructions. Each Series A-1 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 the Series A-1 Stockholders 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 a counterpart to this
Agreement pursuant to which it or 

  
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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. 

8. Termination and Waiver. 

(a) Termination. The Right of First Refusal will not apply to and will terminate upon an IPO. The Voting Agreement set forth in
Section 7 hereof will also 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 with respect to any Investor, such waiver must include the holders of a majority of the shares of Series A-1 Stock
held by the Series A-1 Stockholders, and the holders of a majority of the shares of Series B-1 Stock held by the Series B-1 Stockholders. 

9. 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 an Investor who is required to become a party hereto
will be considered an “Investor” for purposes of this Agreement and any permitted Transferee of Stock held by the Seller will be considered a “Seller” for purposes of this Agreement. 

(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. 

  
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 (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 Series A-1 Stock held by the Series A-1 Stockholders, and (iii) the holders of a majority of the shares of Series B-1 Stock held by the Series B-1 Stockholders. 

(e) Continuity of Other Restrictions. Any Stock not purchased by the Company or any Investor under their Right of First Refusal
hereunder will continue to be subject to all other restrictions imposed upon such Stock by law or agreement, including any restrictions imposed under the Company’s Certificate of Incorporation or Bylaws or by agreement. 

(f) 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. 
 (g) Binding Nature of Exercise. Any exercise of
the Right of First Refusal will be binding upon the party so exercising, and may not be withdrawn without the written consent of the Company or the Investor as to whom it is given, as the case may be, except that such exercise may be withdrawn
unilaterally by the exercising party if there is any legal prohibition as to a party’s consummation of its purchase or sale hereunder. 

(h) Obligation of Company. The Company and the Series A-1 Stockholders agree to use their best efforts to enforce the terms of this
Agreement, to inform the Investors of any breach hereof (to the extent of the Company’s knowledge thereof) and to assist the Investors in the exercise of their rights thereunder. 

(i) 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. 
 (j) 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. 

(k) 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. Notwithstanding the foregoing, the Company and certain Investors are party to the Amended and Restated Stockholder Agreement dated as of August 12, 2003 by and between the Company
and certain holders of the Company’s capital stock (the “Series A-1 Stockholder Agreement”). Should a conflict arise between the terms of this Agreement and the Series A-1 Stockholder Agreement, the terms of this
Agreement shall govern. 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. 

  
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 (l) Conflict. In the event of any conflict between the terms of this Agreement and the
Company’s Certificate of Incorporation, or its Bylaws, the terms of the Company’s Certificate of Incorporation or Bylaws, as the case may be, will control. In the event of any conflict between the terms of this Agreement and any other
agreement to which the Investors are a party or by which such Investor 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. 
 (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. 

(n) Termination of Prior Agreement. The Prior Agreement is hereby amended and restated in its entirety and shall be of no further force
or effect. 
 (o) 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. 
 [Remainder of Page Intentionally Left Blank]

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

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

		 	Paul J. Colan
		 	Chief Financial Officer
		
	Address:	 	500 W. Bethany Drive, Suite 100
		 	Allen, TX 75013

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

							
	[signature block for entities]:	 		 	  

		 		 	 (print name of entity)

				
		 		 	By:	 	  

		 		 	Name:	 	  

		 		 	Title:	 	  

			
	[signature block for individuals]	 		 	 /s/ Clifford H. Higgerson

		 		 	 (signature)

				
		 		 	Print Name:	 	 Clifford H. Higgerson

  
 [PREFERRED
STOCKHOLDER 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 Member

			
	[signature block for individuals]	 		 	 /s/ John Teegen

		 		 	 (signature)

				
		 		 	Print Name:	 	 John Teegen

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

 
			
	INVESTORS:
	
	 THE WELLCOME TRUST LIMITED,

AS TRUSTEE OF THE WELLCOME TRUST

		
	By:	 	 /s/ Sandra Robertson

	Name:	 	 Sandra Robertson

	Title:	 	 Co-Head of Portfolio Management

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

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

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

	Name:	 	
		
	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/ NEA Partners 9, L.P.

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

	Name:	 	  

	Title:	 	  

		
	Address:	 	2490 Sand Hill Road
		 	Menlo Park, CA 94025

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

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

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

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

	Its:	 	Managing Director

  
 [PREFERRED
STOCKHOLDER 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

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

 
			
	INVESTORS:
	
	COMMUNICATIONS VENTURES 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
	
	COMMUNICATIONS VENTURES 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
	
	COMMUNICATIONS VENTURES 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

  
 [PREFERRED
STOCKHOLDER 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

  
 [PREFERRED
STOCKHOLDER 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

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

 
			
	INVESTORS:
	
	INTERWEST INVESTORS Q, VIII, LP
		
	By:	 	 /s/ Harvey B. Cash

	Name:	 	Harvey B. Cash
	Title:	 	Director
		
	Address:	 	2710 Sand Hill Road, Second Floor
		 	Menlo Park, CA 94025
	
	INTERWEST INVESTORS VII, LP
		
	By:	 	 /s/ Harvey B. Cash

	Name:	 	Harvey B. Cash
	Title:	 	Director
		
	Address:	 	2710 Sand Hill Road, Second Floor
		 	Menlo Park, CA 94025
	
	INTERWEST INVESTORS VIII, LP
		
	By:	 	 /s/ Harvey B. Cash

	Name:	 	Harvey B. Cash
	Title:	 	Director
		
	Address:	 	2710 Sand Hill Road, Second Floor
		 	Menlo Park, CA 94025
	
	INTERWEST PARTNERS VII, LP
		
	By:	 	 /s/ Harvey B. Cash

	Name:	 	Harvey B. Cash
	Title:	 	Director
		
	Address:	 	2710 Sand Hill Road, Second Floor
		 	Menlo Park, CA 94025
	
	INTERWEST PARTNERS VIII, LP
		
	By:	 	 /s/ Harvey B. Cash

	Name:	 	Harvey B. Cash
	Title:	 	Director
		
	Address:	 	2710 Sand Hill Road, Second Floor
		 	Menlo Park, CA 94025

  
 [PREFERRED
STOCKHOLDER 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:	 	  

	  

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

 
			
	INVESTORS:
	
	RHO VENTURES IV, L.P.
		
	By:	 	Rho Management Ventures IV, L.L.C.,
		 	Its General Partner
		
	By:	 	 /s/ Joshua Ruch

	Name:	 	Joshua Ruch
	Title:	 	Managing Member
		
	Address:	 	152 West 57th, 23rd Floor
		 	New York, NY 10019
	
	RHO VENTURES IV GMBH & CO. BETEILIGUNGS KG
		
	By:	 	Rho Capital Partners Verwaltungs GmbH,
		 	Its General Partner
		
	By:	 	 /s/ Joshua Ruch

	Name:	 	Joshua Ruch
	Title:	 	Managing Director
		
	Address:	 	152 West 57th, 23rd Floor
		 	New York, NY 10019
	
	RHO VENTURES IV (QP), L.P.
		
	By:	 	Rho Management Ventures IV, L.L.C.,
		 	Its General Partner
		
	By:	 	 /s/ Joshua Ruch

	Name:	 	Joshua Ruch
	Title:	 	Managing Director
		
	Address:	 	152 West 57th, 23rd Floor
		 	New York, NY 10019
	
	RHO MANAGEMENT TRUST I
		
	By:	 	Rho Capital Partners Inc.,
		 	as Investment Adviser
		
	By:	 	 /s/ Joshua Ruch

	Name:	 	Joshua Ruch
	Title:	 	Chief Executive Officer
		
	Address:	 	10 Almaden Blvd., Suite 988
		 	San Jose, CA 95113

  
 [PREFERRED
STOCKHOLDER 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

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

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

	Name:	 	Peter T. Mok
	Title:	 	Managing General Partner
		
	Address:	 	225 Santa Clara Street, Suite 968
		 	San Jose, CA 95113

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

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

	Name:	 	Dr. Meir Barel
	Title:	 	Managing Director
	Address:	 	Possartsrasse 9
		 	D-81679 Munich, Germany
	Fax No.:	 	+49-89-419-43030
	Attn:	 	Andreas Hofbauer
	
	SVE STAR VENTURES ENTERPRISES GMBH & CO. NO. IX KG
		
	By:	 	SVM Star Ventures Managementgesellschaft mbH Nr. 3
		 	Its Managing Partner
		
	By:	 	 /s/ Meir Barel

	Name:	 	Dr. Meir Barel
	Title:	 	Managing Director
	Address:	 	Possartsrasse 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:	 	Managing Director
	Address:	 	Galgaley Haplada Street
		 	Herzelia Pieisch 46733, Israel
	Fax No.:	 	+972-9-9617111
	Attn:	 	Tami Gilboa-Arbel
	
	SVM STAR VENTURES MANAGEMENTGESELLSCHAFT MBH NR. 3
		
	By:	 	 /s/ Meir Barel

	Name:	 	Dr. Meir Barel
	Title:	 	Managing Director
	Address:	 	Possartsrasse 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
		 	Its Managing Partner
		
	By:	 	 /s/ Meir Barel

	Name:	 	Dr. Meir Barel
	Title:	 	Managing Director
	Address:	 	Possartsrasse 9
		 	D-81679 Munich, Germany
	Fax No.:	 	+49-89-419-43030
	Attn:	 	Andreas Hofbauer

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

 
									
	INVESTORS:
	
	JP MORGAN PARTNERS (BHCA)
		
	By:	 	JPMP Master Fund Manager,
		 	its General Partner
			
		 	By:	 	JPMP Capital Corp,
		 		 	its General Partner
				
		 		 	By:	 	Panorama Capital, LLC,
		 		 		 	as Attorney-in-Fact
					
		 		 		 	By:	 	 /s/ Thomas Szymoniak

		 		 		 		 	Thomas Szymoniak,
		 		 		 		 	as Attorney-in-Fact

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

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

	Name:	 	Robert A. Cornman
	Title:	 	Director

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

 
			
	INVESTORS:
	
	JON W. BAYLESS, Personal Property
	
	 /s/ Jon W. Bayless

		
	Address:	 	  

	  

	  

	
	JON W. BAYLESS, JR.
	
	 /s/ By: Jon W. Bayless, Attorney-in-Fact

		
	Address:	 	  

	  

	  

	
	REBECCA L.R. BAYLESS,
	
	 /s/ By: Jon W. Bayless, Attorney-in-Fact

		
	Address:	 	  

	  

	  

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

 
			
	INVESTORS:
	
	REBECCA L.R. BAYLESS,
	Trustee for Christian A.R. Bayless Trust
	
	 /s/ By: Jon W. Bayless, Attorney-in-Fact

		
	Address:	 	  

	  

	  

	
	REBECCA L.R. BAYLESS,
	Trustee for W. Andrew Bayless Trust
	
	 /s/ By: Jon W. Bayless, Attorney-in-Fact

		
	Address:	 	  

	  

	  

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

 
			
	INVESTORS:
	
	CLIFFORD HIGGERSON
	
	 /s/ Clifford H. Higgerson

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

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

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

	Name:	 	Hayden Harris
	Title:	 	Trustee
		
	Address:	 	13875 Waters Rd.
		 	Chelsea, MI 48118

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

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

		
	Address:	 	5022 Jarvis Ave.
		 	La Cañada, CA 91011

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

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

		
	Address:	 	3639 River Pines Drive
		 	Ann Arbor, MI 48103

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

 
			
	INVESTORS:
	
	PATRICK ENNIS
	
	 /s/ Patrick Ennis

		
	Address:	 	4423 Phinney Avenue North #C
		 	Seattle, WA 98103

  
 [PREFERRED
STOCKHOLDER 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

  
 [PREFERRED
STOCKHOLDER AGREEMENT] 

 EXHIBIT A 

INVESTORS 
 Series A-1 Investors

 Clifford Higgerson 
 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. 

Trellis Partners II L.P. 
 NEA
Ventures 2000, L.P. 
 New Enterprise Associates 9 L.P. 

New Enterprise Associates 10 L.P. 

Sevin Rosen Fund VII L.P. 
 Sevin
Rosen VII Affiliates Fund L.P. 
 Sevin Rosen Bayless Management Company 

Communications Ventures IV, L.P. 

Communications Ventures IV CEO Fund, L.P. 

Communications Ventures IV Entrepreneur’s Fund, L.P. 

EDF Ventures I, Limited Partnership 

EDF Ventures II, Limited Partnership 

Beau D. Laskey 
 Jon W. Bayless,
Personal Property 
 Jon W. Bayless, Jr. 

Rebecca L.R. Bayless 
 Rebecca
L.R. Bayless, Trustee for Christian A.R. Bayless Trust 
 Rebecca L.R. Bayless, Trustee for Andrew Bayless Trust 

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

Patrick Ennis 
 InterWest
Investors Q, VIII, LP 
 InterWest Investors VII, LP 

InterWest Investors VIII, LP 

InterWest Partners VII, LP 

InterWest Partners VIII, LP 

James R. Adox 
 Thomas S. Porter
Restated Trust DTD 11-14-05 
 John Teegen 

Northgate Partners, a Delaware Multiple Series LLC 

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

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

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

SVM Star Ventures Managementgesellschaft mbH Nr. 3 

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

Current Ventures II Limited 

  
 1 

 Series B-1 Investors 

Patrick Ennis 
 Hayden H. Harris
Living Trust DTD 3-6-98 
 Beau D. Laskey 

London Pacific Assurance Ltd 
 UC
Berkeley Foundation 
 Clifford H. Higgerson 

The Wellcome Trust Limited, As Trustee of the Wellcome Trust 

Arch Venture Fund III, L.P. 
 Arch
Venture Fund VI, L.P. 
 Arch Venture Fund IV, L.P. 

Arch Entrepreneurs Fund, L.P. 

Arch Venture Fund IV A, L.P. 
 New
Enterprise Associates 9, L.P. 
 New Enterprise Associates 10, L.P. 

James R. Adox 
 Northgate
Partners, a Delaware Multiple Series LLC 
 EDF Ventures II, Limited Partnership 

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

Trellis Partners II L.P. 
 The
Infrastructure Fund, LP 
 The Infrastructure Co-Invest Fund, LP 

  
 2 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 1 TO 

PREFERRED STOCKHOLDER AGREEMENT 

THIS AMENDMENT NO. 1 TO PREFERRED STOCKHOLDER 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 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 and each of the holders of Series A-1 Preferred Stock and Series B-1 Preferred Stock previously entered into that
certain Preferred Stockholder Agreement, dated August 1, 2007 (the “Stockholders 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 Stockholders Agreement; 
 WHEREAS,
Section 9(d) of the Stockholders 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 the Series A-1 Preferred Stock, and 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 Stockholders Agreement, desire to amend the Stockholders 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 Stockholders 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
Stockholders Agreement as a Series B-1 Stockholder, and each New Investor shall be deemed an Investor and a Series B-1 Stockholder (as each such term is defined the Stockholders Agreement) for all purposes contained in the Stockholders 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 Stockholders
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. 

  
 39 

 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 PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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/ Cindy Crnkovich

	Name:	 	 Cindy Crnkovich

	Title:	 	 Vice President

		
	Address:	 	1119 St. Paul Street
		 	Baltimore, MD 21202

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO PREFERRED STOCKHOLDER AGREEMENT 

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

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

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

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

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

	Its:	 	Managing Director

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 
			
	COMMUNICATIONS VENTURES 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
	
	COMMUNICATIONS VENTURES 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
	
	COMMUNICATIONS VENTURES 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. 1 TO PREFERRED STOCKHOLDER 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
	Its:	 	Asst. Treasurer, Asst. Secretary and VP of Finance
	
	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
	Its:	 	Asst. Treasurer, Asst. Secretary and VP of Finance

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO PREFERRED STOCKHOLDER AGREEMENT 

 
	
	CLIFFORD H. HIGGERSON
	
	 /s/ Clifford H. Higgerson

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO PREFERRED STOCKHOLDER 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 Associates L.L.C.

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

  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 1 TO PREFERRED STOCKHOLDER 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/ Hirdmichi Tabata

	Name:	 	Hirdmichi 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. 1 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 2 TO 

PREFERRED STOCKHOLDER AGREEMENT 

THIS AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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 Series A-l 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 and each of the holders of Series A-l Preferred Stock and Series B-1 Preferred Stock previously entered into that certain Preferred Stockholder Agreement, dated August 1, 2007, as amended (the “Stockholders
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 Stockholders Agreement; 

WHEREAS, Section 9(d) of the Stockholders 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 the Series A-1 Preferred Stock, and the holders of a majority of the shares of the Series B-l Preferred Stock; and 

WHEREAS, the undersigned, holding the requisite amount of stock necessary to amend the Stockholders Agreement, desire to amend the
Stockholders 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 Stockholders 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
Stockholders Agreement as a Series B-1 Stockholder, and each New Investor shall be deemed an Investor and a Series B-l Stockholder (as each such term is defined the Stockholders Agreement) for all purposes contained in the Stockholders 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 Stockholders 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. 

  
 54 

 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 PREFERRED STOCKHOLDER 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, LP.
		
	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 PREFERRED STOCKHOLDER 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 FI, 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 PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	CONSENTING INVESTORS:
	
	THE WELLCOME TRUST LIMITED,
	AS TRUSTEE OF THE WELLCOME TRUST
		
	By:	 	 /s/ The Wellcome Trust Limited

	Name:	 	  

	Title:	 	  

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

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER AGREEMENT 

 
	
	CLIFFORD H. HIGGERSON
	
	 /s/ Clifford H. Higgerson

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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 PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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 PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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 PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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
	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

		 	Authorized Signatory
	CFO, Asst. Secretary and Asst. Treasurer

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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 Associates. L.L.C.

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

		
	By:	 	 /s/ Accel Europe Associates 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 PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER AGREEMENT 

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

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

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

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

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

	Its:	 	Managing Director

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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 PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	QUESTER VENTURE PARTNERSHIP
	acting by its general partner
	Quester Venture Managers 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:	 	Quester Capital Management Limited
		 	29 Queen Anne’s Gate
		 	London
		 	SW1H 9BU

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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 Vetnure 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 Vetnure 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 Vetnure Partners
		 		 	1001 Bayhill Drive, Suite 300
		 		 	San Bruno, CA 94066
		 	Facsimile:	 	

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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 PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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 PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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 PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	Witness	 		 		 	

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	Witness	 		 		 	Michael Pascoe

  
 COUNTERPART
SIGNATURE PAGE TO 
 AMENDMENT NO. 2 TO PREFERRED STOCKHOLDER 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	 		 	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, L.P.
	 		 	By:	 	 /s/ Jerusalem Venture Partners IV, (Israel) L.P.

	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 PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 3 TO 

PREFERRED STOCKHOLDER AGREEMENT 

THIS AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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 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 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 and holders of Series A-1 Preferred Stock and Series B-1 Preferred Stock previously entered into that certain
Preferred Stockholder Agreement, dated August 1, 2007, as amended (the “Stockholders Agreement”); 

WHEREAS, Section 9(d) of the Stockholders 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 the Series A-1 Preferred Stock, and 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 Stockholders Agreement; and 

WHEREAS, the undersigned, holding the requisite amount of stock necessary to amend the Stockholders Agreement, desire to amend the
Stockholders 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 Stockholders 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 Stockholders
Agreement as a Series C-2 Stockholder, and each New Investor shall be deemed an Investor and a Series C-2 Stockholder (as each such term is defined the Stockholders Agreement) for all purposes contained in the Stockholders Agreement. 

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

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

“This Preferred Stockholder Agreement (the “Agreement”) is made as of August 1, 2007, by and among Xtera
Communications, Inc., a Delaware corporation (the “Company”), and the holders of the Preferred Stock (as defined herein), of the Company set forth on Exhibit A attached to this Agreement (individually, an
“Investor,” collectively, the “Investors”).” 
 The Recitals are hereby replaced in their
entirety with the following: 
 “RECITALS 

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; 

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:” 
 The following definitions in Section 3 Certain Definitions are hereby replaced in their entirety
with the following: 
 “(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) with respect to which the Corporation receives
aggregate net proceeds (after deduction of underwriting discounts and commissions) of not less than $50,000,000 and (B) with respect to which such Common Stock is listed for trading on either the New York Stock Exchange or the NASDAQ National
Market.” 
 “(h) “Seller” means any Preferred Stockholder proposing to Transfer Stock.” 

  
 79 

 The following definitions are added to Section 3 Certain Definitions: 

“(e) “Preferred Stock” means the Series A-2 Convertible Preferred Stock, Series B-2 Convertible Preferred Stock
and Series C-2 Convertible Preferred Stock.” 
 “(f) “Preferred Stockholder” means a holder of the Series
A-2 Convertible Preferred Stock, Series B-2 Convertible Preferred Stock or Series C-2 Convertible Preferred Stock.” 
 “(k)
“Series C-2 Stockholders” means the holders of the Series C-2 Convertible Preferred Stock.” 
 Section 3 (a)(ii)
Investors’ Right is hereby replaced in its entirety with the following: 
 “(ii) Investors’ Right. If the
Company does not desire to purchase any or all of the Offered Stock, the Investors shall have the right of first refusal to purchase all or none of the Offered Stock; provided, that each such Investor gives written notice of the exercise of such
right to the Seller within fifteen (15) days after the date of mailing or other transmission of the Company’s Notice to such Investor (the “Investors’ Refusal Period”), which notice shall indicate the maximum
number of shares of Stock that such Preferred Stockholder is willing to purchase, including the number of shares of Stock it would purchase if one or more other Preferred Stockholders do not elect to purchase their Preferred Stockholder’s
Share. To the extent the aggregate number of shares such Investors desire to purchase exceeds the Offered Stock available, each such Investor will be entitled to purchase a fraction of the Offered Stock, the numerator of which is the number of
shares of Stock (assuming the Conversion of Preferred Stock into Common Stock) held by such Investor and the denominator of which is the number of shares of Stock (assuming the conversion of Preferred Stock into Common Stock) held by all Investors
exercising their Right of First Refusal (and if any shares of Offered Stock remain unallocated after application of the foregoing, such shares shall be allocated through successive applications thereof).” 

Section 3 (b) Purchase Price is hereby replaced in its entirety with the following: 

“(b) Purchase Price. The purchase price for the Offered Stock to be purchased by the Company or by any Investor exercising its
Right of First Refusal under this Agreement will be the Offered Price, and will be payable as set forth in Section 3(c) hereof. If the Offered Price includes consideration other than cash, the cash equivalent value of the non-cash
consideration will be the fair market value as determined by the Board of Directors of the Company, the holders of a majority the outstanding shares of Preferred Stock (voting together as a single class and not as separate series, and on an
as-converted basis), provided that if the Company and such Investors are unable to reach agreement, then by independent appraisal by an investment banker hired and paid by the Company, but acceptable to such Investors.” 

Section 6 (a)(iv) is hereby replaced in its entirety with the following: 

“four (4) individuals designated by mutual agreement of the Series B-1 Directors, the Series A-1 Directors and the CEO Director (the
“Outside Director”);” 
 Section 6 (b) is hereby replaced in its entirety with the following: 

“ensure that in the event the number of authorized directors is increased beyond ten (10), the persons filling any newly-created seats
shall be approved by both the holders of a majority of the outstanding Common Stock, voting as a class, and the holders of a majority of the Preferred Stock, voting as a class;” 

  
 80 

 Section 8 (b) Waiver is hereby replaced in its entirety with the following: 

“(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 with respect to any Investor, such waiver must include the holders of a majority of the shares of Preferred Stock (voting together as a single class and not as separate series, and
on an as-converted basis).” 
 Section 9 (d) Amendment is hereby replaced in its entirety with the following: 

“(d) Amendment. This Agreement may be amended only by a written instrument executed by (i) the Company and (ii) the
holders of a majority of the shares of Preferred Stock (voting together as a single class and not as separate series, and on an as-converted basis).” 

The reference to “Series A-1 Stockholders” in Section 9 (h) Obligation of the Company is hereby replaced with term
“Preferred Stockholders.” 
 Section 9 (k) Entire Agreement; Successors and Assigns is hereby replaced in its entirety
with the following: 
 “(k) 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. Notwithstanding the foregoing, the Company and certain Investors are party to the Amended and Restated Stockholder Agreement dated as of August 12,
2003 by and between the Company and certain holders of the Company’s capital stock (the “2003 Stockholder Agreement”). Should a conflict arise between the terms of this Agreement and the 2003 Stockholder Agreement, the
terms of this Agreement shall govern. 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.” 
 All other references to “Series A-1” not otherwise amended herein are hereby replaced with term
“Series A-2.” 
 All other references to “Series B-1” not otherwise amended herein are hereby replaced with term “Series B-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 Stockholders 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. 

  
 81 

 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 PREFERRED STOCKHOLDER 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. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	NEW ENTERPRISE ASSOCIATES 10, L.P.
		
	By:	 	NEA Partners 10, L.P.
		 	Its General Partner
		
	By:	 	 /s/ Charles W. Newhall, III

	Name:	 	 Charles W. Newhall, III

	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/ Charles W. Newhall, III

	Name:	 	 Charles W. Newhall, III

	Title:	 	 General Partner

	Address:	 	2490 Sand Hill Road
		 	Menlo Park, CA 94025

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

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

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

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

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

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

		 	Its:	 	Managing Director
			
		 	Address:	 	  

		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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. 3 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	CLIFFORD HIGGERSON
	
	 /s/ Clifford H. Higgerson

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

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

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

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	PATRICK ENNIS
	
	 /s/ Patrick Ennis

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

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

	Name:	 	  

	Title:	 	  

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

	Name:	 	  

	Title:	 	  

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

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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 Entrepreneurs Fund V, 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 IV-A, LP
	 		 	By:	 	 /s/ Jerusalem Venture Partners IV (Israel), LP

	Name:	 	  
	 		 		 	
	Title:	 	  
	 		 	Name:	 	  

	Address:	 	7 West 22nd Street 7th floor	 		 		 	
		 	NY, NY 10010	 		 	Title:	 	  

		 		 		 	Address:	 	24 Hebron Road
		 		 		 		 	Jerusalem, Israel 93542

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	LAGO VENTURES FUND ONE LIMITED
		
	By:	 	 /s/ Lago Ventures Fund One Limited

	Name:	 	  

	Title:	 	  

	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 PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 INVESTORS: 

 

			
	NEWBURY VENTURES III, LP
		
	By:	 	 /s/ Newbury Ventures III, LP

		
	Name:	 	  

		
	Title:	 	  

		
	Address*	 	
	
	NEWBURY VENTURES III GMBH & CO KG
		
	By:	 	 /s/ Newbury Ventures III GMBH & CO KG

		
	Name:	 	  

		
	Title:	 	  

		
	Address*	 	

 

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

		
	Name:	 	  

		
	Title:	 	  

		
	Address*	 	
	
	NEWBURY VENTURES EXECUTIVES III, LP
		
	By:	 	 /s/ Newbury Ventures Executives III, LP

		
	Name:	 	  

		
	Title:	 	  

		
	*Address:	 	  

		 	  

 
 

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

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

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

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

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

 INVESTORS: 
  

									
	RHO MANAGEMENT TRUST I	 		 	RHO VENTURES IV GMBH & CO. BETEILIGUNGS KG
					
	By:	 	RHO CAPITAL PARTNERS INC.	 		 	By:	 	RHO CAPITAL PARTNERS VERWALTUNGS GMBH
					
	By:	 	 /s/ RHO Capital Partners Inc.
	 		 	By:	 	 /s/ RHO Capital Partners Verwaltungs 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:	 	
					
	By:	 	 /s/ Rho Management Ventures, IV, LLC
	 		 	By:	 	 /s/ Rho Management Ventures IV, L.L.C.

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 		 	
		 		 		 	*Address:	 	  

		 		 		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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	 	
	
	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	 	
	
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	General Partner
	*Address:	 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	Name:	 	John J. Dibello	 	Mark G. Cipriano
		 	  

	Title:	 	 Managing Limited Partners

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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, L.L.C.
	 		 	By:	 	 /s/ VantagePoint Venture Associates IV, L.L.C.

					
	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, L.L.C.
	 		 		 	
					
	Name:	 	  
	 		 		 	
					
	Title:	 	  
	 		 		 	
	*Address	 		 		 		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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 Management III, L.L.C.

			
		 	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 Management III, L.L.C.

			
		 	Name:	 	  

			
		 	Title:	 	  

			
		 	Address:	 	  

		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

 
					
	INVESTORS:
	
	ANTHONY JEFFRIES
		
		 	 /s/ Anthony Jeffries

		 	Address:	 	  

		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	MOHR SEED CAPITAL II LP
		
	By:	 	 /s/ Mohr Seed Capital II LP

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	RELL FAMILY PARTNERS LIMITED
		
	By:	 	 /s/ Rell Family Partners Limited

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	DAVE SEGRE
	
	 /s/ Dave Segre

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	JOHN TEEGAN
	
	 /s/ John Teegan

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	UNIVERSITY OF ILLINOIS FOUNDATION
		
	By:	 	 /s/ University Of Illinois Foundation

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	WS INVESTMENT 99B
		
	By:	 	 /s/ WS Investment 99B

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	MIKE PASCOE
	
	 /s/ Mike Pascoe

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 3 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 4 TO 

PREFERRED STOCKHOLDER AGREEMENT 

THIS AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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 Preferred Stockholder Agreement, dated August 1, 2007, as
amended (the “Stockholders Agreement”); 
 WHEREAS, Section 9(d) of the Stockholders Agreement
provides that it may only be amended by a written instrument executed by the Company and the holders of a majority of the shares of the Preferred Stock (as defined in the Stockholders Agreement); 

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, 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 Stockholders Agreement; and 
 WHEREAS,
the undersigned, holding the requisite amount of stock necessary to amend the Stockholders Agreement, desire to amend the Stockholders 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 Stockholders 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 Stockholders Agreement as a Series C-2 Stockholder, and each New Investor shall be deemed an Investor and a Series C-2
Stockholder (as each such term is defined the Stockholders Agreement) for all purposes contained in the Stockholders 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 Stockholders 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. 

  
 124 

 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 PREFERRED STOCKHOLDER 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. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

			
	INVESTORS:
	
	NEW ENTERPRISE ASSOCIATES 10, L.P.
		
	By:	 	NEA Partners 10, L.P.
		 	Its General Partner
		
	By:	 	 /s/ Charles W. Newhall, III

	Name:	 	 Charles W. Newhall, III

	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/ Charles W. Newhall, III

	Name:	 	 Charles W. Newhall, III

	Title:	 	 General Partner

	Address:	 	2490 Sand Hill Road
		 	Menlo Park, CA 94025

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

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

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

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

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

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

		 	Its:	 	Managing Director
		
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	CLIFFORD HIGGERSON
	
	 /s/ Clifford Higgerson

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

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

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

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	PATRICK ENNIS
	
	 /s/ Patrick Ennis

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

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

	Name:	 	  

	Title:	 	  

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

	Name:	 	  

	Title:	 	  

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

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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 Entrepreneurs Fund V, 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 IV-A, LP
	 		 	By:	 	 /s/ Jerusalem Venture Partners Iv (Israel), LP

	Name:	 	  
	 		 	Name:	 	  

	Title:	 	  
	 		 	Title:	 	  

	Address:	 	 7 West 22nd Street 7th floor

NY, NY 10010
	 		 	Address:	 	 24 Hebron Road
 Jerusalem, Israel
93542

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	LAGO VENTURES FUND ONE LIMITED
		
	By:	 	 /s/ Lago Ventures Fund One Limited

	Name:	 	  

	Title:	 	  

	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 PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

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

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 INVESTORS: 
  

									
	STAR GROWTH ENTERPRISE	 		 	STAR VENTURES MANAGEMENTGESELLSCHAFT MBH NR. 3 & CO.
					
	By:	 	 /s/ Meir Barel
	 		 	By:	 	 /s/ Meir Barel

					
	Name:	 	 Dr. Meir Barel
	 		 	Name:	 	 Dr. Meir Barel

					
	Title:	 	 Managing Director
	 		 	Title:	 	 Managing Director

					
	Address*	 		 		 	Address*	 	
			
	STAR MANAGEMENT OF INVESTMENTS NO. II (2000) L.P.	 		 	SVE STAR VENTURES ENTERPRISES
					
	By:	 	 /s/ Meir Barel
	 		 	By:	 	 /s/ Meir Barel

					
	Name:	 	 Dr. Meir Barel
	 		 	Name:	 	 Dr. Meir Barel

					
	Title:	 	 Managing Director
	 		 	Title:	 	 Managing Director

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

		 		 		 		 	  

	By:	 	 /s/ Meir Barel
	 		 		 	
					
	Name:	 	 Dr. Meir Barel
	 		 		 	
					
	Title:	 	 Managing Director
	 		 		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 INVESTORS: 
  

											
	RHO MANAGEMENT TRUST I	 		 	RHO VENTURES IV GMBH & CO. BETEILIGUNGS KG
						
	By:	 	RHO CAPITAL PARTNERS INC.	 		 		 	By:	 	RHO CAPITAL PARTNERS VERWALTUNGS GMBH
					
	By:	 	 /s/ RHO Capital Partners Inc.
	 		 	By:	 	 /s/ RHO Capital Partners Verwaltungs 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, L.L.C.

					
	Name:	 	  
	 		 	Name:	 	  

					
	Title:	 	  
	 		 	Title:	 	  

					
	Address*	 		 		 	*Address:	 	  

		 		 		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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	 	
	
	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	 	
	
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	John V. Jaggers
	Title:	 	Vice President
	*Address:	 	
		
	*Address	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	TVM V INFORMATION TECHNOLOGY GMBH & CO. KG
		
	By:	 	 /s/ TVM V Information Technology GMBH & CO. KG

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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, L.L.C.
	 		 	By:	 	 /s/ VantagePoint Venture Associates IV, L.L.C.

					
	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, L.L.C.
	 		 		 	
					
	Name:	 	  
	 		 		 	
					
	Title:	 	  
	 		 		 	
	*Address	 		 		 		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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 Management III, L.L.C.

		
	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 Management III, L.L.C.

		
	Name:	 	  

		
	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 
					
	INVESTORS:
	
	ANTHONY JEFFRIES
		
		 	 /s/ Anthony Jeffries

		 	Address:	 	  

		 		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	MOHR SEED CAPITAL II LP
		
	By:	 	 /s/ Mohr Seed Capital II LP

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	RELL FAMILY PARTNERS LIMITED
		
	By:	 	 /s/ Rell Family Partners Limited

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	DAVE SEGRE
	
	 /s/ Dave Segre

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	JOHN TEEGAN
	
	 /s/ John Teegan

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	UNIVERSITY OF ILLINOIS FOUNDATION
		
	By:	 	 /s/ University Of Illinois Foundation

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	WS INVESTMENT 99B
		
	By:	 	 /s/ WS Investment 99B

	Name:	 	  

	Title:	 	  

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	MIKE PASCOE
	
	 /s/ Mike Pascoe

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER 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 PREFERRED STOCKHOLDER AGREEMENT 

 
			
	NEW INVESTORS:
	
	Timothy Russell Davison as Trustee under a Declaration of Trust dated 30 April 2010
	
	 /s/ Timothy Russell Davison

	Authorised Signatory,
	Timothy Russell Davison
	
	INDEPENDENT WEALTH MANAGEMENT CONSULTANTS LIMITED
		
	By:	 	 /s/ T.R. Davison

	Name:	 	 T.R. Davison

	Title:	 	  

	
	 /s/ Stuart Barnes

	Stuart Barnes
	
	 /s/ Michael Hamilton-Smith

	Michael Hamilton-Smith
	
	 /s/ Stuart Barnes

	Steve Webb acting by his duly authorised 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 authorised attorney Stuart Barnes
	
	 /s/ Stuart Barnes

	Russell Johnson acting by his duly authorised attorney Timothy Russell Davison
	
	 /s/ Stuart Barnes

	Scott White acting by his duly authorised attorney Stuart Barnes
	
	 /s/ Stuart Barnes

	Steve Desbrulais acting by his duly authorised attorney Stuart Barnes
	
	ASTON UNIVERSITY
		
	By:	 	 /s/ Gareth Evans

	Name:	 	 Gareth Evans

	Title:	 	 Deputy University Secretary

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 4 TO PREFERRED STOCKHOLDER AGREEMENT 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 5 TO 

PREFERRED STOCKHOLDER AGREEMENT 

THIS AMENDMENT NO. 5 TO PREFERRED STOCKHOLDER AGREEMENT (this “Amendment”) is made and entered into as of
April 21, 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”). 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-2 Preferred Stock, Series B-2 Preferred Stock and Series C-2 Preferred Stock previously entered into that certain Preferred Stockholder Agreement, dated August 1, 2007, as
amended (the “Stockholder Agreement”); 
 WHEREAS, Section 9(d) of the Stockholder Agreement
provides that it may only be amended by a written instrument executed by the Company and the holders of a majority of the shares of the Preferred Stock; 

WHEREAS, the holders of the requisite amount of stock necessary to amend the Stockholder Agreement approved this Amendment by written
consent dated on or about April 21, 2011. 
 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. Amended
Provisions. The Stockholder Agreement is hereby amended such that: 
 The following definitions in Section 1 Certain Definitions are
hereby replaced in their entirety with the following: 
 “(j) “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 Seller’s spouse, lineal descendant or antecedent, father, mother, brother or sister of
the Seller, the adopted child or adopted grandchild of the Seller, or the spouse of any child, adopted child, grandchild or adopted grandchild of the Seller, or to a trust or trusts for the exclusive benefit of the Seller or the Seller’s family
members as listed in this Section; 

 (ii) any transfers of Stock to an Affiliate, other than transfers or
distributions of Stock from a general partner to its limited partners, a corporation to its stockholders or other similar transfers from an entity to its equity owners; or 

(iii) any transfer of Stock to an Investor; 

provided that in each and all such cases, (A) the Seller shall inform the Company and each Investor by written notice prior to effecting
such permitted transfer of Stock, and (B) such transferee or Affiliate, as the case may be, if not an existing Investor under the Agreement, shall furnish the Company and each Investor with an executed counterpart copy of this Agreement and
agree to become bound thereby as was the Seller. Such transferred Stock shall remain “Stock” hereunder, and the transferee shall be treated as was the Seller of such Stock hereunder, and shall assume all rights and obligations of such
Seller hereunder.” 
 Section 3 (a)(ii) Investors’ Right is hereby replaced in its entirety with the following: 

“(ii) Investors’ Right. If the Company does not desire to purchase any or all of the Offered Stock, the Investors shall have
the right of first refusal to purchase all or none of the Offered Stock; provided, that each such Investor gives written notice of the exercise of such right to the Seller within fifteen (15) days after the date of mailing or other transmission
of the Company’s Notice to such Investor (the “Investors’ Refusal Period”), which notice shall indicate the maximum number of shares of Stock that such Preferred Stockholder is willing to purchase, including the
number of shares of Stock it would purchase if one or more other Preferred Stockholders do not elect to purchase their Preferred Stockholder’s Share. To the extent the aggregate number of shares such Investors desire to purchase exceeds the
Offered Stock available, each such Investor will be entitled to purchase a fraction of the Offered Stock, the numerator of which is the number of shares of Stock (assuming the Conversion of Preferred Stock into Common Stock) held by such Investor
and the denominator of which is the number of shares of Stock (assuming the conversion of Preferred Stock into Common Stock) held by all Investors exercising their Right of First Refusal (and if any shares of Offered Stock remain unallocated after
application of the foregoing, such shares shall be allocated through successive applications thereof). 
 Upon the expiration of the
Investors’ Refusal Period, the number of shares of Stock to be purchased by each Investor who has elected to participate in purchasing the Offered Stock (the “Participating Investors”) shall be determined as follows:
(i) first, there shall be allocated to each Investor electing to purchase, a number of shares of Stock equal to the lesser of (A) the number of shares of Stock as to which such Investor accepted as set forth in its respective acceptance
notice or (B) such Investor’s Pro Rata Fraction, which shall be equal to the product obtained by multiplying the total number of shares of Stock not purchased by the Company by a fraction, the numerator of which is the total number of
shares of Preferred Stock owned by such Investor, and the denominator of which is the total number of shares of Preferred Stock held by all Investors, in each case as of the date of the Seller’s Notice, and (ii) second, the balance, if
any, not allocated under clause (i) above, shall be allocated to those Investors who within the Investors’ Refusal Period delivered an acceptance notice that set forth a number of shares of Stock that exceeded their respective Pro Rata
Fractions, in each case on a pro rata basis in proportion to the number of shares of Stock held by each such Investor up to the amount of such excess. Within ten (10) days after expiration of the Investors’ Refusal Period (the
“Confirmation Period”), the Seller will give written notice to the Company and the Participating Investors, specifying the aggregate number of shares of Offered Stock that were subscribed for by the Investors (the
“Subscribed Offered Stock”) exercising their Rights of First Refusal (the “Confirmation Notice”). Should the Subscribed Offered Stock not equal or exceed the number

  
 168 

 
of shares of Offered Stock, the Participating Investors may notify the Seller, within ten (10) days after expiration of the Confirmation Period, of their intent to purchase an amount equal
to the difference between (i) the Offered Stock and (ii) the Subscribed Offered Stock (such amount, the “Remaining Offered Stock”). Should the Participating Investors collectively elect not to purchase an amount
equal to the Remaining Offered Stock, the Right of First Refusal under this Agreement shall be deemed to have been waived with respect to the Offered Stock.” 

2. 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. 
 3. Entire Agreement. The Stockholder 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. 

  
 169 

 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

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 6 TO 

PREFERRED STOCKHOLDER AGREEMENT 

THIS AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER 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”).
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-2 Preferred Stock, Series B-2 Preferred Stock and Series C-2 Preferred Stock previously entered into that certain Preferred Stockholder Agreement, dated August 1, 2007, as
amended (the “Stockholder Agreement”); 
 WHEREAS, Section 9(d) of the Stockholder Agreement
provides that it may only be amended by a written instrument executed by the Company and the holders of a majority of the shares of the 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 Stockholder Agreement; and 

WHEREAS, the holders of the requisite amount of stock necessary to amend the Stockholder Agreement, desire to amend the Stockholder
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 Stockholder 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 of the Stockholder
Agreement as a Series D-3 Stockholder, and each New Investor shall be deemed an Investor and a Series D-3 Stockholder (as each such term is defined in the Stockholders Agreement) for all purposes contained in the Stockholders Agreement. 

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

The following definitions in Section 1 Certain Definitions are hereby replaced in their entirety with the following: 

“(e) “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.” 
 “(f)
“Preferred Stockholder” means a holder of the Series A-3 Convertible Preferred Stock, Series B-3 Convertible Preferred Stock, Series C-3 Convertible Preferred Stock or Series D-3 Convertible Preferred Stock.” 

The following definition is 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: 
 “(l) “Series D-3 Stockholders” means the
holders of the Series D-3 Convertible Preferred Stock.” 
 Section 6(a) is hereby replaced in its entirety with the following: 

“(a) elect and appoint to the Board of Directors of the Company the following persons: 

(i) two individuals designated by the holders of a majority of the outstanding shares of Series B-3 Preferred Stock, Series C-3 Preferred Stock and Series D-3 Preferred Stock (each a “Preferred Director”), voting together as a single class, one of which shall be the designee of ARCH Venture Partners
(“AVP”) for so long as AVP and its Affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted for any stock dividends, combinations or splits with respect to such shares occurring after
the date hereof), and one of which shall be the designee of New Enterprise Associates (“NEA”) for so long as NEA and its affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted for any
stock dividends, combinations or splits with respect to such shares occurring after the date hereof); 
 (ii) three individuals designated by
the holders of a majority of the outstanding shares of Series A-3 Preferred Stock (each, a “Series A-3 Director”), voting as a single class, one of which shall be the designee of Sevin Rosen Fund VII, L.P.
(“SRF”) for so long as SRF and its Affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted for any stock dividends, combinations or splits with respect to such shares occurring after
the date hereof); 

  
 172 

 (iii) one individual designated by the holders of a majority of the outstanding shares of Common
Stock, voting as a class, who shall be the then-current Chief Executive Officer of the Company (the “CEO Director”); and 

(iv) four individuals designated by mutual agreement of the Preferred Directors and the Series A-3 Directors and the CEO Director (the
“Outside Directors”).” 
 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.” 
 All other references to “Series B-1 Director” not otherwise amended herein are hereby replaced with the term “Preferred
Director.” 
 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 Stockholder 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. 
 Signature Pages Follow 

  
 173 

 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. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	Name:	 	 Peter P. Gray

	Title:	 	 Managing Director, Investments

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

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

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

		 	Name:	 	  

		 	Title:	 	  

		 	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/ NEA Partners 9, L.P.

		 	Name:	 	  

		 	Title:	 	  

		 	Address:	 	2490 Sand Hill Road
		 		 	Menlo Park, CA 94025

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER 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. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	UC BERKELEY FOUNDATION
		
	By:	 	  

	Name:	 	Lina Wang
	Title:	 	  

		
	Address:	 	2080 Addison, Suite 4200
		 	Berkeley, CA 94720
		
	By:	 	  

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

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	CLIFFORD HIGGERSON
	
	 /s/ Clifford Higgerson

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

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER 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. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	Address:	 	
		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	PATRICK ENNIS
	
	 /s/ Patrick Ennis

	Address:	 	3150 139th Avenue SE
		 	Building 4
		 	Bellevue, WA 98005

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER 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. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	By:	 	 /s/ Accel Europe Associates L.L.C.

	Name:	 	  

	Title:	 	  

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

	Name:	 	  

	Title:	 	  

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

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	JON BAYLESS
	
	 /s/ Jon Bayless

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

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER 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 Entrepreneurs Fund V, 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 IV-A, 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. 6 TO PREFERRED STOCKHOLDER 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. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 INVESTORS: 
  

									
	NEWBURY VENTURES III, LP	 		 	NEWBURY VENTURES CAYMAN III, LP
					
	By:	 	 /s/ Joseph Kell
	 		 	By:	 	Newbury Venture Partners III, LLC
		 		 		 	Its General Partner
	Name:	 	 Joseph Kell
	 		 	By:	 	 /s/ Joseph Kell

					
	Title:	 	 CFO
	 		 	Name:	 	 Joseph Kell

					
	Address*	 		 		 	Title:	 	 CFO

					
		 		 		 	Address*	 	
			
	NEWBURY VENTURES III GMBH &CO KG	 		 	NEWBURY VENTURES EXECUTIVES III, LP
					
	By:	 	Newbury Venture Partners III, LLC	 		 	By:	 	Newbury Venture Partners III, LLC
	Its Managing Limited Partner	 		 	Its General Partner
					
	By:	 	 /s/ Joseph Kell
	 		 	By:	 	 /s/ Joseph Kell

					
	Name:	 	 Joseph Kell
	 		 	Name:	 	 Joseph Kell

					
	Title:	 	 CFO
	 		 	Title:	 	 CFO

					
	Address*	 		 		 	Address*	 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 INVESTORS: 
  

									
	STAR GROWTH ENTERPRISE	 		 	STAR VENTURES MANAGEMENTGESELLSCHAFT MBH NR. 3 & CO.
					
	By:	 	 /s/ Meir Barel
	 		 	By:	 	 /s/ Meir Barel

					
	Name:	 	 Meir Barel
	 		 	Name:	 	 Meir Barel

					
	Title:	 	 Managing Director
	 		 	Title:	 	 Managing Director

					
	Address*	 		 		 	Address*	 	
			
	STAR MANAGEMENT OF INVESTMENTS NO. II (2000) L.P.	 		 	SVE STAR VENTURES ENTERPRISES
					
	By:	 	 /s/ Meir Barel
	 		 	By:	 	 /s/ Meir Barel

					
	Name:	 	 Meir Barel
	 		 	Name:	 	 Meir Barel

					
	Title:	 	 Director
	 		 	Title:	 	 Managing Director

					
	Address*	 		 		 	Address*	 	
				
		 		 		 	
	 SVM STAR VENTURES

MANAGEMENTGESELLSCHAFT MBH NR. 3
	 		 	*Address:	 	  

		 		 		 	  

	By:	 	 /s/ Meir Barel
	 		 		 	
					
	Name:	 	 Meir Barel
	 		 		 	
					
	Title:	 	 Managing Director
	 		 		 	

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER 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. 6 TO PREFERRED STOCKHOLDER 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	 	
	
	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:	 	
	
	SEVIN ROSEN BAYLESS MANAGEMENT COMPANY
		
	By:	 	 /s/ John V. Jaggers

	Name:	 	 John V. Jaggers

	Title:	 	 Vice President

	*Address:	 	
		
	*Address	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	ANTHONY JEFFRIES
	
	 /s/ Anthony Jeffries

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	MOHR SEED CAPITAL II LP
		
	By:	 	 /s/ Robert Mohr

	Name:	 	 Robert Mohr

	Title:	 	  

		
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	RELL FAMILY PARTNERS LIMITED
		
	By:	 	 /s/ Rell Family Partners Limited

	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	DAVE SEGRE
	
	 /s/ Dave Segre

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	JOHN TEEGEN
	
	 /s/ John Teegen

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	THOMAS A. KELLEY & ASSOCIATES
	PROFIT SHARING PLAN
		
	By:	 	 /s/ Tom A. Kelley

	Name:	 	 Tom A. Kelley

	Title:	 	  

		
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	UNIVERSITY OF ILLINOIS FOUNDATION
		
	By:	 	 /s/ Laura A. Vossman

	Name:	 	 Laura A. Vossman

	Title:	 	  

		
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	WS INVESTMENT 99B
		
	By:	 	 /s/ WS Investment 99B

	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	ARTHUR TRUEGER
	
	 /s/ Arthur Trueger

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	STUART BARNES
	
	 /s/ Stuart Barnes

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	TIMOTHY RUSSELL DAVISON
	
	 /s/ Timothy Russell Davison

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	STEVEN DESBRUSLAIS
	
	 /s/ Steven Desbrulais

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	JOHN ELLISON
	
	 /s/ John Ellison

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

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

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	INDEPENDENT WEALTH MANAGEMENT CONSULTANTS LIMITED
		
	By:	 	 /s/ Timothy Davison

	Name:	 	 Timothy Davison

	Title:	 	 Director

		
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	RUSSELL JOHNSON
	
	 /s/ Russell Johnson

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER 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. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	STEPHEN WEBB
	
	 /s/ Stephen Webb

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	SCOTT WHITE
	
	 /s/ Scott White

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	DAVID WINTERBURN
	
	 /s/ David Winterburn

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	JEANNE ANN BAYLESS
	
	 /s/ Jeanne Ann Bayless

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	JON W. BAYLESS, JR.
	
	 /s/ Jon W. Bayless, Jr.

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	REBECCA L.R. BAYLESS
	
	 /s/ Rebecca L.R. Bayless

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	JON BAYLESS, SEPARATE PROPERTY
	
	 /s/ Jon Bayless

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	REBECCA BAYLESS, TRUSTEE FOR CHRISTIAN A.R. BAYLESS TRUST
	
	 /s/ Rebecca Bayless

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	REBECCA BAYLESS, TRUSTEE FOR W. ANDREW BAYLESS TRUST
	
	 /s/ Rebecca Bayless

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	HAYDEN HARRIS
	
	 /s/ Hayden Harris

	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER 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. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 
			
	INVESTORS:
	
	NORTHGATE PARTNERS LLC, a Delaware Multiple Series LLC
		
	By:	 	 /s/ Northgate Partners LLC

	Name:	 	  

	Title:	 	  

		
	Address:	 	  

		 	  

  
 COUNTERPART
SIGNATURE TO 
 AMENDMENT NO. 6 TO PREFERRED STOCKHOLDER AGREEMENT 

 XTERA COMMUNICATIONS, INC. 

AMENDMENT NO. 7 TO 

PREFERRED STOCKHOLDER AGREEMENT 

THIS AMENDMENT NO. 7 TO PREFERRED STOCKHOLDER 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 Series A-3 Preferred Stock, Series B-3 Preferred Stock, Series C-3 Preferred Stock and Series D-3 Preferred Stock previously entered into that certain Preferred Stockholder Agreement, dated August 1,
2007, as amended (the “Stockholder Agreement”); 
 WHEREAS, Section 9(d) of the Stockholder
Agreement provides that it may only be amended by a written instrument executed by the Company and the holders of a majority of the shares of the 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 Stockholder 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 Stockholder Agreement; and 

WHEREAS, the holders of the requisite amount of stock necessary to amend the Stockholder Agreement, desire to amend the Stockholder
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 Stockholder 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 of the Stockholder
Agreement as a Series E-3 Stockholder, and each New Investor shall be deemed an Investor and a Series E-3 Stockholder (as each such term is defined in the Stockholders Agreement) for all purposes contained in the Stockholders Agreement. Each holder
of Series E-3 Preferred Stock that is already party to the Voting Agreement shall also be added to Exhibit A to the Voting Agreement as a Series E-3 Investor. 

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

The following definitions in Section 1 Certain Definitions are hereby replaced in their entirety with the following: 

“(e) “Preferred Stock” means the Series A-3 Convertible Preferred Stock, Series B-3 Convertible Preferred Stock,
Series C-3 Convertible Preferred Stock, Series D-3 Convertible Preferred Stock and Series E-3 Convertible Preferred Stock.” 
 “(f)
“Preferred Stockholder” means a holder of the Series A-3 Convertible Preferred Stock, Series B-3 Convertible Preferred Stock, Series C-3 Convertible Preferred Stock, Series D-3 Convertible Preferred Stock or Series E-3
Convertible Preferred Stock.” 
 The following definition is 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: 
 “(l) “Series E-3
Stockholders” means the holders of the Series E-3 Convertible Preferred Stock.” 
 Section 6(a)(i) is hereby replaced in its
entirety with the following: 
 “(i) two individuals designated by the holders of a majority of the outstanding shares of Series B-3
Preferred Stock, Series C-3 Preferred Stock, Series D-3 Preferred Stock and Series E-3 Preferred Stock (each a “Preferred Director”), voting together as a single class, one of which shall be the designee of ARCH Venture
Partners (“AVP”) for so long as AVP and its Affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted for any stock dividends, combinations or splits with respect to such shares occurring
after the date hereof), and one of which shall be the designee of New Enterprise Associates (“NEA”) for so long as NEA and its affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted
for any stock dividends, combinations or splits with respect to such shares occurring after the date hereof); 
 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 Stockholder 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] 

  
 224 

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

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

	Paul J. Colan
	Chief Financial Officer

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

		
	Name:	 	 Nick Moakes

		
	Title:	 	 Director

 
			
	HOLDERS:
	
	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:	 	  

  

 
			
	HOLDERS:
	
	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

  

 
	
	HOLDER:
	
	 /s/ Clifford H. Higgerson

	Clifford H. Higgerson

 
	
	HOLDER:
	
	 /s/ Jon Bayless

	Jon Bayless

 
			
	HOLDER:
	
	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

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

	Name:	 	 David Quinlivan

	Title:	 	 Managing Member

 
	
	HOLDER:
	
	 /s/ Jon W. Bayless

	Jon W. Bayless, Separate Property

 
	
	HOLDER:
	
	 /s/ Jon Hopper

	Jon Hopper

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

	Name:	 	Jon Hopper
	Title:	 	ExecutorEX-4.4

 Exhibit 4.4 

XTERA COMMUNICATIONS, INC. 

AMENDED AND RESTATED STOCKHOLDER AGREEMENT 

This Amended and Restated Stockholder Agreement (the “Agreement”) is made as of August 12, 2003, by
and among Xtera Communications, Inc., a Delaware corporation (the “Company”), Mohammed Islam, an individual residing in the State of Texas and a holder of outstanding Common Stock of the Company (the “Initial
Stockholder”), the holders of Common Stock and Series A-1 Preferred Stock of the Company listed on Schedule I hereto (the “Investors”) and such other persons as may become stockholders of the Company
pursuant to a Transfer (as defined below) made in accordance with Sections 1(k) and 8(c) hereof (each a “Transferee” and collectively, the “Transferees”). The Investors and their Transferees are
collectively referred to herein as the “Investors” and each an “Investor”. 

RECITALS 
 A. The Company
and the Initial Stockholder desire for the Investors to purchase shares of the Company’s Series A-1 Preferred Stock pursuant to the Series A-1 Preferred Stock Purchase Agreement by and among the Company and certain of the Investors dated of
even date herewith (the “Purchase Agreement”). 
 B. The execution of this Agreement is a condition to the closing
of the transactions contemplated by the Purchase Agreement. 
 C. The Investors, the Initial Stockholder and the Company desire to enter
into this Agreement and grant the rights contained herein in order to fulfill such condition. 
 D. Certain of the Investors and the Initial
Stockholder have previously entered into an Amended and Restated Stockholder Agreement with the Company, dated January 10, 2001 (the “Prior Agreement”). 

E. All parties hereto wish to amend, restate and supersede the Prior Agreement by entering into this Agreement. 

NOW, THEREFORE, in consideration of the mutual promises herein contained, and other consideration, the receipt and adequacy of which hereby is
acknowledged, and intending to be bound, the parties hereto agree to amend, restate and supersede the Prior Agreement 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) “Investor’s Share” means, as to the Right of Co-Sale, the
percentage determined by dividing (A) the number of shares of Stock held by the Investor (calculated on an as-converted basis) by (B) the number of shares of Stock held by the Seller and all Investors participating in the Right of Co-Sale
(calculated on an as-converted basis). 
 (c) “IPO” means the first closing of a bona fide, firm commitment
underwritten public offering of the Company’s securities registered under the Securities Act of 1933, as amended, with aggregate proceeds to the Company of not less than $35,000,000 and a per share price to the public of not less than $2.168
(subject to proportionate adjustment in the event of a stock split, reverse stock split, recapitalization or stock dividend). 
 (d)
“Offered Stock” means all Stock proposed to be Transferred by the Seller. 
 (e) “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. 
 (f) “Right of Co-Sale” means the right of co-sale provided to the
Investors in Section 4 of this Agreement. 
 (g) “Preferred Stock” means the Series A-1 Preferred Stock of the
Company, par value $0.001 (the “Series A-1 Preferred”). 
 (h) “Right of First Refusal”
means the right of first refusal provided to the Company and the Investors in Section 3 of this Agreement. 
 (i)
“Seller” means any Initial Stockholder proposing to Transfer Stock. 
 (j) “Stock” means and
includes all Common Stock and Preferred Stock of the Company (whether already issued or issuable upon conversion of Preferred Stock). 
 (k)
“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 Seller’s spouse, lineal descendant or antecedent, father, mother, brother or sister of the Seller, the
adopted child or adopted grandchild of the Seller, or the spouse of any child, adopted child, grandchild or adopted grandchild of the Seller, or to a trust or trusts for the exclusive benefit of the Seller or the Seller’s family members as
listed in this Section; or 
 (ii) any transfers of Stock to an Affiliate; 

provided that in each and all such cases, (A) the Seller shall inform the Company and each Investor by written notice prior to effecting such permitted
transfer of Stock, and (B) such 

  
 -2- 

 
transferee or Affiliate, as the case may be, shall furnish the Company and each Investor with an executed counterpart copy of this Agreement and agree to become bound thereby as was the Seller.
Such transferred Stock shall remain “Stock” hereunder, and the transferee shall be treated as was the Seller of such Stock hereunder, and shall assume all rights and obligations of such Seller hereunder. 

2. Notice of Proposed Transfer. Before any Seller may effect any Transfer of Stock, the Seller must give at the same time to the
Company and to each Investor a written notice signed by the Seller (the “Seller’s Notice”) stating (a) the Seller’s bona fide intention to Transfer such Offered Stock and the name and address of the proposed
transferee (the “Transferee”); (b) the number of shares of the Offered Stock; and (c) the bona fide cash price or, in reasonable detail, other consideration, per share for which the Seller proposes to Transfer such
Offered Stock (the “Offered Price”). Upon the request of the Company or any of such Investors, the Seller will promptly furnish information to the Company and to the Investors as may be reasonably requested to establish that
the offer and Transferee are bona fide. 
 3. Right of First Refusal. 

(a) The Right. 
 (i)
Company’s Initial Right. The Company has the right of first refusal to purchase any or all of the Offered Stock, if the Company gives written notice of the exercise of such right to the Seller within fifteen (15) days after the date
of its receipt of the Seller’s Notice to the Company (the “Company’s Refusal Period”). If the Company does not desire to purchase all of the Offered Stock, within ten (10) days after expiration of the
Company’s Refusal Period, the Company will give written notice to each Investor, specifying the number of shares of Offered Stock not subscribed for by the Company through exercise of its Right of First Refusal (the “Company’s
Notice”). 
 (ii) Investors’ Right. If the Company does not desire to purchase any or all of the Offered Stock,
the Investors shall have the right of first refusal to purchase all or none of the Offered Stock; provided, that each such Investor gives written notice of the exercise of such right to the Seller within fifteen (15) days after the date of
mailing or other transmission of the Company’s Notice to such Investor (the “Investors’ Refusal Period”). To the extent the aggregate number of shares such Investors desire to purchase exceeds the Offered Stock
available, each such Investor will be entitled to purchase a fraction of the Offered Stock, the numerator of which is the number of shares of Stock (assuming the Conversion of Preferred Stock into Common Stock) held by such Investor and the
denominator of which is the number of shares of Stock (assuming the conversion of Preferred Stock into Common Stock) held by all Investors exercising their Right of First Refusal (and if any shares of Offered Stock remain unallocated after
application of the foregoing, such shares shall be allocated through successive applications thereof). Within ten (10) days after expiration of the Investors’ Refusal Period, the Seller will give written notice to the Company and each
Investor, specifying the number of shares of Offered Stock that were subscribed for by the Investors exercising their Rights of First Refusal (the “Confirmation Notice”). 

  
 -3- 

 (b) Purchase Price. The purchase price for the Offered Stock to be purchased by the
Company or by any Investor exercising its Right of First Refusal under this Agreement will be the Offered Price, and will be payable as set forth in Section 3(c) hereof. If the Offered Price includes consideration other than cash, the cash
equivalent value of the non-cash consideration will be determined by the Board of Directors of the Company in good faith, which determination will be binding upon the Company, each Investor and the Seller, absent fraud or error. 

(c) Payment. Payment of the purchase price for the Offered Stock purchased by the Company or by an Investor exercising its Right of
First Refusal will be made within fifteen (15) days after the later of (i) the end of the Company’s Refusal Period, or (ii) the delivery of the Company’s Notice and the end of the Investors’ Refusal Period. Payment of
the purchase price will be made, at the option of the Company or the exercising Investor, (i) in cash (by check or wire transfer at the option of the purchaser), (ii) by cancellation of all or a portion of any outstanding indebtedness of
the Seller to the Company or the Investor, as the case may be, or (iii) by any combination of the foregoing. 
 (d) Rights as an
Investor. If the Company or any Investor exercises its Right of First Refusal to purchase the Offered Stock, then, upon the date the notice of such exercise is given by the Company or any Investor, the Seller will have no further rights as a
holder of the Offered Stock except the right to receive payment for the Offered Stock from the Company or the Investors in accordance with the terms of this Agreement, and the Seller will forthwith cause all certificate(s) evidencing such Offered
Stock to be surrendered for transfer to the Company or the Investor, as the case may be. 
 4. Right of Co-Sale. 

(a) Right of Co-Sale. If the Company and the Investors have waived or failed to timely exercise their Rights of First Refusal under
paragraph 3 with respect to any portion of the Offered Stock, then, subject to the Investors’ Right of Co-Sale, the Seller may Transfer to the Transferee such remaining portion of the Offered Stock as was specified in the Seller’s Notice,
by giving written notice to each Investor within five (5) days after the date of the expiration of the Investors’ Refusal Period (the “Right of Co-Sale Notice”), specifying the date of the Transfer of the Offered
Stock to such Transferee which shall not occur earlier than fifteen (15) days nor later than thirty (30) days after the date of mailing or other transmission of the Right of Co-Sale Notice (the “Closing”), and the
number of shares and type of Stock that the Seller desires to Transfer to the Transferee. If the Seller desires to Transfer to the Transferee such Offered Stock, each Investor shall have the right to require, as a condition to such sale or transfer,
that the Transferee agree to purchase from such Investor, at the same price per share and on the same terms and conditions as involved in such sale or disposition by the Seller, a number of shares of such Investor’s Stock (regardless of the
class and series thereof) equal to a percentage of the Offered Stock equivalent to the Investor’s Share. The amount of Offered Stock the Seller may actually Transfer to the Transferee (after the application of this Section 4) shall be
reduced by the number of shares of Investors’ Stock that the Transferee purchases pursuant to this Section 4(a). This Right of Co-Sale shall not apply with respect to Offered Stock sold or to be sold to Investors or the Company under their
Right of First Refusal. 

  
 -4- 

 (b) Consummation of Co-Sale. An Investor may exercise the Right of Co-Sale by delivering
to the Seller five (5) days before the Closing, a notice (the “Co-Sale Confirmation Notice”) setting forth the number of shares, not to exceed such Investor’s Share, and one or more certificates, properly endorsed
for Transfer, representing a number of shares (not to exceed such Investor’s Share) of such Stock to be Transferred by the Seller on behalf of such Investor exercising his or her Right of Co-Sale. At the Closing, one or more certificates or
other instruments, properly endorsed for Transfer, representing the Stock listed on the Co-Sale Confirmation Notice, will be Transferred and delivered to the Transferee by the Seller as set forth in the Right of Co-Sale Notice, in consummation of
the Transfer of the Offered Stock pursuant to the terms and conditions specified in the Right of Co-Sale Notice, and the Seller will remit, or will cause to be remitted, to each participating Investor, within ten (10) days after such Closing,
that portion of the proceeds of the Transfer to which each participating Investor is entitled by reason of each Investor’s participation in such Transfer pursuant to the Right of Co-Sale. After the Closing, the Company shall promptly deliver a
certificate for the remaining balance of the securities held by each participating Investor, if any, to each such participating Investor. 

(c) Seller’s Right To Transfer. If the Company and each Investor have not elected to purchase all of the Offered Stock under their
Right of First Refusal, and to the extent that the Investors have not exercised their Right of Co-Sale, the Seller may Transfer that portion of the Offered Stock permitted to be sold, to any person named as a purchaser or other Transferee in the
Seller’s Notice, at the Offered Price, provided that such Transfer (i) is consummated within thirty (30) days after the date of the Right of Co-Sale Notice, (ii) is on terms no more favorable to the Seller than the terms proposed
in the Seller’s Notice and (iii) is in accordance with all the terms of this Agreement. If the Offered Stock is not so Transferred during such thirty (30) day period, then the Seller may not Transfer any of such Offered Stock without
complying again in full with the provisions of this Agreement. 
 5. Multiple Series, Classes or Types of Stock. If the
Offered Stock consists of more than one series, class or type of Stock, the Seller has the right to Transfer hereunder each such series, class or type; provided, however, that if an Investor exercising the Right of Co-Sale does not hold any of such
series class or type, or any other security convertible at the Investor’s option into shares of such series class or type, and the proposed Transferee is not willing, at the Closing, to purchase some other series, class or type of Stock from
such Investor, or is unwilling to purchase any Stock from such Investor at the Closing, then such Investor will have the put right (the “Put Right”) set forth in Section 6(b) hereof. 

6. Refusal to Transfer; Put Right. 

(a) Refusal to Transfer. Any attempt by any Seller to Transfer any Stock in violation of any provision of this Agreement will be void.
The Company will not be required (i) to transfer on its books any Stock that has been sold, gifted or otherwise Transferred in violation of this Agreement, or (ii) to treat as owner of such Stock, or to accord the right to vote or pay
dividends to any purchaser, donee or other Transferee to whom such Stock may have been so Transferred. 

  
 -5- 

 (b) Put Right. If a Seller Transfers any Stock in contravention of the Right of Co-Sale
under this Agreement (a “Prohibited Transfer”), or if the proposed Transferee of Offered Stock desires to purchase a class, series or type of stock offered by the Seller, and an Investor exercising the Right of Co-Sale does
not hold any shares of such class, series or type, or any other security convertible at the Investor’s option into shares of such series class or type, or the proposed Transferee is unwilling to purchase any Stock from an Investor, such
Investor may, by delivery of written notice to such Seller (a “Put Notice”) within ten (10) days after (i) the Closing as defined in subsection 4(a) above, or (ii) the date on which such Investor becomes aware
of the Prohibited Transfer or the terms thereof, require such Seller to purchase from such Investor, for cash or such other consideration as the Seller received in the Prohibited Transfer or at the Closing, a number of shares of Stock (of the same
class or type as transferred in the Prohibited Transfer or at the Closing if such Investor then owns Stock of such class or type; otherwise of Preferred Stock or Common Stock at the election of the Investor) having a purchase price equal to the
aggregate purchase price the Investor would have received in the closing of such Prohibited Transfer if such Investor had elected to exercise its Right of Co-Sale with respect thereto or in the Closing if the Transferee had been willing to purchase
the Stock of the Investor. The closing of such sale to the Seller will occur within ten (10) days after the date of such Investor’s Put Notice to such Seller. 

7. Board of Directors; Voting. So long as at least 1,000,000 shares of Preferred Stock (as adjusted for any stock dividends,
combinations or splits with respect to such shares occurring after the date hereof) remain outstanding, each Initial Stockholder and Investor hereby agrees to vote all shares of the Company’s capital stock now or hereafter directly or
indirectly owned (of record or beneficially) by such Initial Stockholder or Investor and otherwise to take such action as shall be necessary to: 

(a) elect and appoint to the Board of Directors of the Company the following persons: 

(i) three (3) individuals designated by the holders of a majority of the outstanding shares of Preferred Stock, voting as a single
class, one (1) of which shall be the designee of Sevin Rosen Fund VII, L.P. (“SRF”) for so long as SRF and its Affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted for any stock
dividends, combinations or splits with respect to such shares occurring after the date hereof), and one (1) of which shall be the designee of Communications Ventures IV, L.P. (“ComVen”) for so long as ComVen and its
affiliates hold not less than 2,000,000 shares of Preferred Stock in the aggregate (as adjusted for any stock dividends, combinations or splits with respect to such shares occurring after the date hereof); and 

(ii) two (2) individuals designated by the holders of a majority of the outstanding shares of Common Stock, voting as a class, one
(1) of which shall be the then-current Chief Executive Officer of the Company and one (1) of which shall be the designee of the holders of a majority of the outstanding shares of Common Stock held by persons and entities whose shares of
Common Stock were not issued by reason of the conversion of any series of the Company’s Preferred Stock, voting as a class; 

  
 -6- 

 (b) ensure that in the event the number of authorized directors is increased beyond five (5), the
persons filling any newly-created seats shall be approved by both the holders of a majority of the outstanding Common Stock, voting as a class, and the holders of a majority of the Preferred Stock, voting as a class; 

(c) allow for Enterprise Development Fund II, Limited Partnership (“EDF”) to have an observer attend all meetings of
the Board of Directors for so long as EDF and its Affiliates hold not less than 700,000 shares of Preferred Stock in the aggregate (as adjusted for any stock dividends, combinations or splits with respect to such shares occurring after the date
hereof); provided that such observer shall first enter into a standard nondisclosure agreement with the Company; 
 (d) allow for ARCH
Venture Fund IV, L.P. (“ARCH”) to have an observer attend all meetings of the Board of Directors for so long as ARCH and its Affiliates hold not less than 700,000 shares of Preferred Stock in the aggregate (as adjusted for
any stock dividends, combinations or splits with respect to such shares occurring after the date hereof); provided that such observer shall first enter into a standard nondisclosure agreement with the Company; and 

(e) ensure that the Board of Directors shall consist of the following persons immediately following the first closing of the Company’s
Series A-1 Preferred financing pursuant to the Purchase Agreement: Mohammed Islam, Jon Bayless (who shall be Chairman), Cliff Higgerson and Hayden Harris. 

8. Restrictive Legend and Stop Transfer Orders. 

(a) Legend. Each Initial Stockholder and Investor 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 Initial Stockholder or Investor: 

“THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN RIGHTS OF FIRST REFUSAL, RIGHTS OF CO-SALE AND/OR VOTING AGREEMENTS AS
SET FORTH IN AN AMENDED AND RESTATED STOCKHOLDER 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 RIGHTS OF FIRST REFUSAL, RIGHTS OF CO-SALE AND
VOTING AGREEMENTS ARE BINDING ON CERTAIN TRANSFEREES OF THESE SHARES.” 
 (b) Stop Transfer Instructions. Each Initial
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 the Initial
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 a counterpart to this Agreement pursuant to which it 

  
 -7- 

 
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. 

9. Termination and Waiver. 

(a) Termination. The Right of First Refusal and Right of Co-Sale will not apply to and will terminate upon an IPO. The Voting Agreement
set forth in Section 7 hereof will also 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. 

10. Miscellaneous Provisions. 

(a) 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 and or (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 an Investor who is required to become a party hereto
will be considered an “Investor” for purposes of this Agreement and any permitted Transferee of Stock held by the Seller will be considered a “Seller” for purposes of this Agreement. 

  
 -8- 

 (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 Initial Stockholders, and (iii) the holders of a majority 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. 
 (e) Continuity
of Other Restrictions. Any Stock not purchased by the Company or any Investor under their Right of First Refusal hereunder will continue to be subject to all other restrictions imposed upon such Stock by law or agreement, including any
restrictions imposed under the Company’s Certificate of Incorporation or Bylaws or by agreement. 
 (f) 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. 

(g) Binding Nature of Exercise. Any exercise of the Right of First Refusal or Right of Co-Sale will be binding upon the party so
exercising, and may not be withdrawn without the written consent of the Company or the Investor as to whom it is given, as the case may be, except that such exercise may be withdrawn unilaterally by the exercising party if there is any legal
prohibition as to a party’s consummation of its purchase or sale hereunder. 
 (h) Obligation of Company. The Company and the
Initial Stockholders agree to use their best efforts to enforce the terms of this Agreement, to inform the Investors of any breach hereof (to the extent of the Company’s knowledge thereof) and to assist the Investors in the exercise of their
rights thereunder. 
 (i) 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. 
 (j) 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. 

(k) 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 Investor 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. 

  
 -9- 

 (l) Conflict. In the event of any conflict between the terms of this Agreement and the
Company’s Certificate of Incorporation, or its Bylaws, the terms of the Company’s Certificate of Incorporation or Bylaws, as the case may be, will control. In the event of any conflict between the terms of this Agreement and any other
agreement to which the Initial Stockholder is a party or by which such Initial 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. 
 (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. 

(n) Termination of Prior Agreement. The Prior Agreement is hereby amended and restated in its entirety and shall be of no further force
or effect. 
 [Remainder of Page Intentionally Left Blank] 

  
 -10- 

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

							
	The Company:	 		 	XTERA COMMUNICATIONS, INC.
		 		 	a Delaware corporation
				
		 		 	By:	 	 /s/ Xtera Communications, Inc.

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	500 W. Bethany Drive
		 		 		 	Allen, TX 75013

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	NEW ENTERPRISE ASSOCIATES 10, L.P.
		 		 	By:	 	NEA Partners 10, L.P.
		 		 	Its General Partner
				
		 		 	By:	 	 /s/ Thomas C. McConnell

		 		 	Name:	 	Thomas C. McConnell
		 		 	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/ Thomas C. McConnell

		 		 	Name:	 	Thomas C. McConnell
		 		 	Address:	 	2490 Sand Hill Road
		 		 		 	Menlo Park, CA 94025
			
		 		 	NEA VENTURES 2000, L.P.
				
		 		 	By:	 	 /s/ NEA Ventures 2000, L.P.

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	2490 Sand Hill Road
		 		 		 	Menlo Park, CA 94025

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

									
	The 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 Road, Suite 1670
 Dallas, TX
75240

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	COMMUNICATIONS VENTURES IV, L.P.
				
		 		 	By:	 	 /s/ Clifford Higgerson

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

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

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

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	CHARLES M. AJOURI
			
		 		 	 /s/ Charles M. Ajouri

		 		 	Address:	 	  

		 		 		 	  

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	THOMAS A. KELLEY & ASSOCIATES PROFIT SHARING PLAN
				
		 		 	By:	 	 /s/ Thomas A. Kelley & Associates Profit Sharing Plan

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	  

		 		 		 	  

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	JON W. BAYLESS, Personal Property
			
		 		 	 /s/ Jon W. Bayless

		 		 	Address:	 	  

		 		 		 	  

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	JAMES R. ADOX
			
		 		 	 /s/ James R. Adox

		 		 	Address:	 	  

		 		 		 	  

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	BEAU D. LASKEY
			
		 		 	 /s/ Beau D. Laskey

		 		 	Address:	 	  

		 		 		 	  

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	THOMAS S. PORTER RESTATED TRUST
				
		 		 	By:	 	 /s/ Thomas S. Porter Restated Trust

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	  

		 		 		 	  

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

 
							
	The Investors:
		 	ARCH Venture Fund III, L.P.
		 		 	By:	 	ARCH Venture Partners, LLC
		 		 	Its:	 	General Partner
				
		 		 	By:	 	/s/ Arch Venture Partners, LLC
		 		 	Its:	 	Managing Director
			
		 		 	ARCH Venture Fund IV, L.P.
		 		 	By:	 	ARCH Venture Partners IV, LLC
		 		 	Its:	 	General Partner
				
		 		 	By:	 	/s/ Arch Venture Partners IV, LLC
		 		 	Its:	 	Managing Director
			
		 		 	ARCH Entrepreneurs Fund, L.P.
		 		 	By:	 	ARCH Venture Partners IV, LLC
		 		 	Its:	 	General Partner
				
		 		 	By:	 	/s/ Arch Venture Partners IV, LLC
		 		 	Its:	 	Managing Director

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	EDF VENTURES, LIMITED PARTNERSHIP
				
		 		 	By:	 	 /s/ Jim Adox

		 		 	Name:	 	Jim Adox
		 		 	Title:	 	Vice President of EDM III, Inc., General Partner of Enterprise Ventures III, Limited Partnership, which is the General Partner of EDF Ventures, Limited Partnership
		 		 	Address:	 	425 North Main Street
		 		 		 	Ann Arbor, MI 48104-1147
			
		 		 	ENTERPRISE DEVELOPMENT FUND II, LIMITED PARTNERSHIP
				
		 		 	By:	 	 /s/ Jim Adox

		 		 	Name:	 	Jim Adox
		 		 	Title:	 	Vice President of EDM, Inc., General Partner of Enterprise Ventures, Limited Partnership, which is the General Partner of Enterprise Development Fund II, Limited Partnership
		 		 	Address:	 	425 North Main Street
		 		 		 	Ann Arbor, MI 48104-1147

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	WS INVESTMENT COMPANY 99B,
				
		 		 	By:	 	 /s/ WS Investment Company 99B

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	650 Page Mill Road
		 		 		 	Palo Alto, CA 94304-1050

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	THOMAS E. SPARKS, JR.
				
		 		 	By:	 	 /s/ Thomas E. Sparks, Jr.

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	  

		 		 		 	  

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	UNIVERSITY OF ILLINOIS FOUNDATION
				
		 		 	By:	 	 /s/ University of Illinois Foundation

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	Harker Hall, 1305 West Green Street
		 		 		 	Urbana, Illinois 61801

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	UNIVERSITY OF CALIFORNIA, BERKELEY FOUNDATION
				
		 		 	By:	 	 /s/ University of California, Berkeley Foundation

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	2440 Bancroft Way #211
		 		 		 	Berkeley, California 94720-4200

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	CIENA CORPORATION
				
		 		 	By:	 	 /s/ Ciena Corporation

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	1201 Winterson Road
		 		 		 	Linthicum, MD 21090

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	HOOK PARTNERS III, LP
				
		 		 	By:	 	 /s/ Hook Partners III, LP

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	One Lincoln Centre, Suite 1550
		 		 		 	5400 LBJ Freeway
		 		 		 	Dallas, TX 75240
			
		 		 	HOOK COMMUNICATIONS PARTNERS, LP
				
		 		 	By:	 	 /s/ Hook Communications Partners, LP

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	One Lincoln Centre, Suite 1550
		 		 		 	5400 LBJ Freeway
		 		 		 	Dallas, TX 75240
			
		 		 	HOOK PARTNERS V, LP
				
		 		 	By:	 	 /s/ Hook Partners V, LP

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	One Lincoln Centre, Suite 1550
		 		 		 	5400 LBJ Freeway
		 		 		 	Dallas, TX 75240

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	RHO VENTURES IV, L.P.
		 		 	By:	 	Rho Management Ventures IV, L.L.C., General Partner
				
		 		 	By:	 	 /s/ Rho Management Ventures IV, L.L.C.

				
		 		 	Name:	 	  

				
		 		 	Title:	 	  

			
		 		 	RHO VENTURES IV GmbH & CO. BETEILIGUNGS KG
		 		 	By:	 	Rho Capital Partners Verwaltungs GmbH, General Partner
				
		 		 	By:	 	 /s/ Rho Capital Partners Verwaltungs GmbH

				
		 		 	Name:	 	  

				
		 		 	Title:	 	  

			
		 		 	RHO VENTURES IV (QP), L.P.
		 		 	By:	 	Rho Management Ventures IV, L.L.C., General Partner
				
		 		 	By:	 	 Rho Management Ventures IV, L.L.C.

				
		 		 	Name:	 	  

				
		 		 	Title:	 	  

			
		 		 	RHO MANAGEMENT TRUST I
		 		 	By:	 	Rho Management Company, Inc. as Investment Adviser
				
		 		 	By:	 	 /s/ Rho Management Company, Inc. as Investment Adviser

				
		 		 	Name:	 	  

				
		 		 	Title:	 	  

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	SVM Star Ventures Managementgesellschaft mbH Nr. 3 & Co. Beteiligungs KG Nr. 3
			
		 		 	By: SVM Star Ventures Managementgesellschaft mbH Nr. 3
				
		 		 	By:	 	 /s/ SVM Star Ventures Managementgesellschaft mbH Nr. 3

		 		 	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 GmbH & Co. Nr. IX KG
			
		 		 	By: SVM Star Ventures Managementgesellschaft mbH Nr. 3
				
		 		 	By:	 	 /s/ SVM Star Ventures Managementgesellschaft mbH Nr. 3

		 		 	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
				
		 		 	By:	 	 /s/ SVM Star Ventures Managementgesellschaft mbH Nr. 3

		 		 	Name:	 	Dr. Meir Barel
		 		 	Title:	 	Managing Director
		 		 	Address:	 	Possartstrasse 9
		 		 		 	D-81679 Munich, Germany
		 		 	Fax. No.:	 	+49-89-419-43030
		 		 	Attn:	 	Andreas Hofbauer

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	Star Management of Investments No. II (2000) L.P.
				
		 		 	By:	 	SVM Star Venture Capital Management Ltd.
				
		 		 	By:	 	 /s/ SVM Star Venture Capital Management Ltd.

		 		 	Name:	 	Dr. Meir Barel
		 		 	Title:	 	Director
		 		 	Address:	 	11 Galgaley Haplada Street
		 		 		 	P.O. Box 12600
		 		 		 	Herzelia Pituach 46733, Israel
		 		 	Fax. No.:	 	+972-9-951-2889
		 		 	Attn:	 	Yael Reznik Cramer
			
		 		 	Star Growth Enterprise, a German Civil Law Partnership (with limitation of liability)
			
		 		 	By: SVM Star Ventures Managementgesellschaft mbH Nr. 3
				
		 		 	By:	 	 /s/ SVM Star Ventures

		 		 	Name:	 	Dr. Meir Barel
		 		 	Title:	 	Managing Director
		 		 	Address:	 	Possartstrasse 9
		 		 		 	D-81679 Munich, Germany
		 		 	Fax No.:	 	+49-89-419-43030
		 		 	Attn:	 	Andreas Hofbauer

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

									
	The Investors:	 		 	ACCEPTED BY:
			
		 		 	CENTERPOINT VENTURE FUND III, L.P.
				
		 		 	BY:	 	CENTERPOINT ASSOCIATES III, L.P., Its General Partner
				
		 		 	BY:	 	CENTERPOINT ASSOCIATES MANAGEMENT III, L.L.C. Its General Partner
					
		 		 		 	BY:	 	 /s/ Centerpoint Associates Management III, L.L.C.

		 		 		 	Name:	 	Cam McMartin
		 		 		 	Title:	 	CFO

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	LONDON PACIFIC ASSURANCE LIMITED
				
		 		 	By:	 	 /s/ Ron Green

		 		 	Name:	 	Ron Green
		 		 	Address:	 	6 Minden Place,
		 		 		 	St. Helier, Jersey, Channel Islands
				
		 		 	Copy to:	 	 Berkeley International Capital
 Corporation 650
California Street,
 28th Floor San Francisco, CA 94108

Attn: Mr. A. I. Trueger

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL FOUNDATION INVESTMENT FUND, INC.
				
		 		 	By:	 	 /s/ Mark W. Yusko

		 		 	Name:	 	Mark W. Yusko
		 		 	Title:	 	Assistant Treasurer

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	THE INFRASTRUCTURE FUND, LP
				
		 		 	By:	 	IF MANAGEMENT COMPANY, LLC, its General Partner
				
		 		 	By:	 	 /s/ Peter Hankin

		 		 	Name:	 	Peter Hankin
		 		 	Title:	 	Managing Member
		 		 	Address:	 	3000 Sand Hill Road
		 		 		 	Building 3, Suite 255
		 		 		 	Menlo Park, CA 94025 USA
			
		 		 	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:	 	3000 Sand Hill Road
		 		 		 	Building 3, Suite 255
		 		 		 	Menlo Park, CA 94025 USA

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	DIETRICH R. ERDMANN
				
		 		 	By:	 	 /s/ Dietrich R. Erdmann

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	Renggstrasse 36 — P.O. Box
		 		 		 	6052 Hergiswil - Switzerland

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	Mohr Seed Capital II, L.P.
				
		 		 	By:	 	 /s/ Bob Mohr

		 		 	Name:	 	Bob Mohr
		 		 	Title:	 	Partner
		 		 	Address:	 	5400 LBJ Freeway, Suite 1325
		 		 		 	Dallas, TX 75240
		 		 	Tel. No.:	 	972-239-0394

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	University Technology Investors, LP
				
		 		 	By:	 	 /s/ Mark Harris

		 		 	Name:	 	Mark Harris
		 		 	Title:	 	General Partner
		 		 	Address:	 	173 Spring Street Suite 200
		 		 		 	Pleasanton, CA 94566

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	AETHER PARTNERS, LP
				
		 		 	By:	 	 /s/ Aether Partners, LP

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	7731 Chalkstone Street
		 		 		 	Dallas, TX 75248

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

					
	Initial Stockholder:	 		 	
			
		 		 	 /s/ Mohammed N. Islam

		 		 	Mohammed N. Islam

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	SCTI, L.P.
		 		 	A Delaware limited partnership
				
		 		 	By:	 	 /s/ Mark Masur

		 		 	Name:	 	Mark Masur
		 		 	Address:	 	5949 Sherry Lane, Suite 1450
		 		 		 	Dallas, TX 75225

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	DALI, HOOK PARTNERS ENTREPRENEURS FUND, L.P.
				
		 		 	By:	 	 /s/ Dali, Hook Partners Entrepreneurs Fund, L.P.

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	  

		 		 		 	  

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The Investors:	 		 	DALI HOOK PARTNERS L.P.
				
		 		 	By:	 	 /s/ Dali Hook Partners L.P.

		 		 	Name:	 	  

		 		 	Title:	 	  

		 		 	Address:	 	  

		 		 		 	  

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

							
	The 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:	 	  

		 		 		 	  

  
 ***AMENDED AND
RESTATED STOCKHOLDER AGREEMENT*** 

 SCHEDULE 1 

SCHEDULE OF INVESTORS 

Common Stockholders 

ARCH Venture Fund III, L.P. 

ARCH Venture Fund IV, L.P. 

ARCH Entrepreneurs Fund, L.P. 

Enterprise Development Fund II, L.P. 

EDF Ventures, Limited Partnership 

New Enterprise Associates 9, L.P. 

New Enterprise Associates 10, L.P. 

NEA Ventures 2000, L.P. 

ComVentures IV, L.P. 

ComVentures IV CEO Fund, L.P. 

ComVentures IV Entrepreneurs’ Fund, L.P. 

Sevin Rosen Fund VII L.P. 

Sevin Rosen VII Affiliates Fund L.P. 

Sevin Rosen Bayless Management Company 

WS Investment Company 99B 

Thomas E. Sparks, Jr. 

University of Illinois Foundation 

University of California Berkeley Foundation 

CIENA Corporation 
 Hook
Partners III, LP 
 Hook Partners IV, LP 

Hook Partners V, L.P. 

 Hook Communications Partners, LP 

Dietrich R. Erdmann 
 Rho
Ventures IV, L.P. 
 Rho Ventures IV GmbH & CO. Beteiligungs KG 

Rho Ventures IV (QP), L.P. 
 Rho
Management Trust I 
 SVM Star Ventures Managementgesellschaft mbH Nr. 3 & Co. Beteiligungs KG Nr. 3 

SVE Star Ventures Enterprises GmbH & Co. Nr. IX KG 

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

SVM Star Ventures Managementgesellschaft mbH Nr. 3 

Star Management of Investments No. 2 (2000) L.P. 

CenterPoint Venture Fund III, L.P. 

London Pacific Assurance Limited 

University of North Carolina at Chapel Hill Foundation Investment Fund, Inc. 

The Infrastructure Fund, LP 

The Infrastructure Co-Invest Fund, LP 

Mohr Seed Capital II, L.P. 

University Technology Investors, LP 

Aether Partners, LP 
 SCTI, L.P.

 Centerpoint Venture Fund III, L.P. 

Dali Hook Partners, L.P. 
 Dali
Hook Partners Entrepreneurs Fund L.P. 
 Trellis Partners II, L.P.

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"}]]