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                                                                    EXHIBIT 10.2

            SIXTH AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT


         AGREEMENT made as of the 16th day of June, 2000, by and among Sitara
Networks, Inc., a Delaware corporation (the "Company"), Malik Z. Khan (the
"Founder") and each of the persons listed as Investors on Schedule RRA-1 hereto,
as amended (the "Investors").

         WHEREAS, the Company, certain of the Investors and the Founder entered
into a Fifth Amended and Restated Registration Rights Agreement dated January
14, 2000, as amended (the "Existing Registration Rights Agreement"), in
conjunction with the issuance by the Company to certain Investors of shares of
the Company's Series F Convertible Preferred Stock, $.00001 par value (the
"Series F Preferred Stock"), all of which are convertible into shares of the
Company's Common Stock, $.00001 par value (the "Common Stock");

         WHEREAS, the Company is this date issuing to certain of the Investors
up to 4,650,000 shares of the Company's Series G Convertible Preferred Stock,
$.00001 par value (the "Series G Preferred Stock"), all of which are convertible
into shares of Common Stock, pursuant to a Series G Convertible Preferred Stock
Purchase Agreement dated as of the date hereof (the "Series G Preferred Stock
Purchase Agreement"); and

         WHEREAS, the parties hereto, who hold sufficient Shares of Registrable
Stock (as hereinafter defined) to amend the Existing Registration Rights
Agreement, desire to amend and restate the Existing Registration Rights
Agreement in order to add the purchasers of the Series G Preferred Stock as
parties thereto, to grant such purchasers registration rights with respect to
the Common Stock issuable upon conversion of the Series G Preferred Stock, as
hereinafter provided and to amend certain other provisions of the Existing
Registration Rights Agreement.

         NOW, THEREFORE, in consideration of the mutual covenants herein
contained and other valuable consideration, the receipt and sufficiency of which
is hereby acknowledged, the parties hereto hereby agree as follows:

         1. Definitions. The following terms shall be used in this Agreement
with the following respective meanings:

         "Affiliate" means (i) any Person directly or indirectly controlling,
controlled by or under common control with another Person; (ii) any Person
owning or controlling ten (10%) percent or more of the outstanding voting
securities of such other Person; (iii) any officer, director or partner of such
Person; and (iv) if such Person is an officer, director or partner, any such
company for which such Person acts in such capacity.

         "Commission" means the Securities and Exchange Commission.

         "Common Stock" means and includes (a) the Company's Common Stock,
$.00001 par value per share, as authorized on the date of this Agreement and (b)
any other securities into which or for which the securities described in (a)
above may be converted or exchanged pursuant to a plan of recapitalization,
reorganization, merger, sale of assets or otherwise.
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         "Exchange Act" means the Securities Exchange Act of 1934, or any
successor Federal statute, and the rules and regulations of the Commission (or
of any other Federal agency then administering the Exchange Act) thereunder, all
as the same shall be in effect at the time.

         "Founder Registrable Stock" means (a) all Common Stock now or hereafter
owned by the Founder or any Affiliate of the Founder (other than the Company),
and (b) any other shares of Common Stock issued in respect of such shares by way
of a stock dividend, or stock split or in connection with a combination of
shares, recapitalization, merger or consolidation or reorganization; provided,
however, that shares of Common Stock shall only be treated as Founder
Registrable Stock if and so long as they have not been (i) sold to or through a
broker or dealer or underwriter in a public distribution or a public securities
transaction, or (ii) sold in a transaction exempt from the registration and
prospectus delivery requirements of the Securities Act under Section 4(l)
thereof so that all transfer restrictions and restrictive legends with respect
to such Common Stock are removed upon the consummation of such sale.

         "Holder" means any holder of Registrable Stock or Founder Registrable
Stock.

         "Initial Public Offering" means the effective date for the Company's
first registration statement covering a public offering of securities of the
Company under the Securities Act.

         "Investors" means the persons listed as Investors on Schedule RRA-1
hereto, as amended from time to time.

         "NASD" means the National Association of Securities Dealers, Inc.

         "Person" means any natural person, partnership, corporation or other
legal entity.

         "Registrable Stock" means (a) the Common Stock issued or issuable upon
conversion of the Series A Convertible Preferred Stock, $.00001 par value (the
"Series A Preferred Stock"), the Series B Convertible Preferred Stock, $.00001
par value (the "Series B Preferred Stock"), the Series C Convertible Preferred
Stock, $.00001 par value (the "Series C Preferred Stock"), the Series D
Convertible Preferred Stock, $.00001 par value (the "Series D Preferred Stock"),
the Series E Convertible Preferred Stock, $.00001 par value (the "Series E
Preferred Stock"), the Series F Preferred Stock, and the Series G Preferred
Stock, whether or not such Common Stock is owned by any Investors; (b) all
Common Stock now or hereafter owned by any Investor which is acquired otherwise
than upon conversion of the Series A Preferred Stock, the Series B Preferred
Stock, the Series C Preferred Stock, the Series D Preferred Stock, the Series E
Preferred Stock, the Series F Preferred Stock and the Series G Preferred Stock
so long as it is held by any Investor or an Affiliate of any Investor; (c) any
other shares of Common Stock issued in respect of such shares by way of a stock
dividend, or stock split or in connection with a combination of shares,
recapitalization, merger or consolidation or reorganization; provided, however,
that shares of Common Stock shall only be treated as Registrable Stock if and so
long as they have not been (i) sold to or through a broker or dealer or
underwriter in a public distribution or a public securities transaction, or (ii)
sold in a transaction exempt from the registration and prospectus delivery
requirements of the Securities Act under Section 4(l) thereof so that all
transfer restrictions and restrictive legends with respect to such Common Stock
are removed upon the consummation of such sale; (d) all shares of Common Stock
issued or issuable upon exercise of any warrant now or

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hereafter held by Lighthouse Capital Partners II, L.P. or Lighthouse Capital
Partners III, L.P.; and (e) all shares of Common Stock issued or issuable upon
exercise of any warrant now or hereafter held by Deutsche Banc Alex Brown
Incorporated.

         "Registration Statement" means a registration statement filed by the
Company with the Commission for a public offering and sale of securities of the
Company (other than a registration statement on Form S-8, Form S-4, or successor
forms, or any registration statement covering only securities proposed to be
issued in exchange for securities or assets of another corporation).

         "Securities Act" means the Securities Act of 1933, or any successor
Federal statute, and the rules and regulations of the Commission (or of any
other Federal agency then administering the Securities Act) thereunder, all as
the same shall be in effect at the time.

         2. Required Registration.

                  (a) At any time after the earlier of (i) 180 days after any
         Registration Statement covering a public offering of securities of the
         Company under the Securities Act having become effective and (ii) June
         30, 2002, the Holder or Holders of at least twenty-five (25%) percent
         of all Registrable Stock then outstanding (the "Initiating Holders")
         may by notice in writing to the Company request the Company to register
         under the Securities Act all or any portion of shares of Registrable
         Stock held by such Initiating Holder or Holders for sale in the manner
         specified in such notice, provided, that, (i) at least fifteen (15%)
         percent of the total amount of Registrable Stock shall be included in
         the Public Offering or (ii) the reasonably anticipated aggregate price
         to the public of such lesser number of shares of Registrable Stock and
         Founder Registrable Stock to be included in such public offering shall
         exceed $10,000,000. Notwithstanding anything to the contrary contained
         herein, the Company shall not be required to seek to cause a
         Registration Statement to become effective pursuant to this Section 2:
         (A) within a period of 90 days after the effective date of a
         Registration Statement 180 days if the Registration Statement is for
         the Initial Public Offering) filed by the Company (other than a
         Registration Statement on Forms S-4, S-8 or any successors thereto),
         provided that the Company shall use its best efforts to cause a
         registration requested hereunder to be declared effective promptly
         following such period if such request is made during such period; (B)
         if the Company shall furnish to the Holders a certificate signed by the
         President of the Company stating that in the good faith judgment of the
         Board of Directors it would be materially detrimental to the Company or
         its shareholders for a Registration Statement to be filed at such time,
         or that it would require disclosure of material non-public information
         relating to the Company which, in the reasonable opinion of the Board
         of Directors, should not be disclosed, then the Company's obligation to
         use all reasonable efforts to register, qualify or comply under this
         Section 2 shall be deferred for a period not to exceed ninety (90) days
         from the date of receipt of written request from such Holders;
         provided, however, that the Company may not utilize this deferral right
         more than once in any twelve-month period.

                  (b) Following receipt of any notice given under this Section 2
         by the Initiating Holders, the Company shall immediately notify in
         writing all Holders that such registration is to be effected and shall
         use its best efforts to register under the Securities

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         Act, for public sale in accordance with the method of disposition
         specified in such notice from requesting Holders, the number of shares
         of Registrable Stock and Founder Registrable Stock, specified in such
         notice (and in all notices received by the Company pursuant hereto).
         Holders, other than the Initiating Holders, shall notify the Company of
         their desire to participate in the Registration within twenty (20) days
         of the Company's notice to them. The Holders of a majority of the
         shares of Registrable Stock to be sold in such offering may designate
         the managing underwriter of such offering, subject to the approval of
         the Company, which approval shall not be unreasonably withheld or
         delayed. The Company shall be obligated to register Registrable Stock
         and Founder Registrable Stock pursuant to this Section 2 on two
         occasions only, provided, however, that such obligation shall be deemed
         satisfied only when a Registration Statement covering all shares of
         Registrable Stock, specified in notices received as aforesaid and which
         have not been withdrawn by the Holder thereof, for sale in accordance
         with the method of disposition specified by the Initiating Holders,
         shall have become effective. A registration which does not become
         effective after the Company has filed a Registration Statement with
         respect thereto solely by reason of the refusal of the Initiating
         Holders to proceed shall be deemed to have been effected by the Company
         at the request of such Initiating Holders unless such requesting
         Holders shall have elected to pay all the Company's reasonable expenses
         in connection with such registration.

                  (c) If the Registration Statement is to cover an underwritten
         distribution and in the good faith judgment of the managing underwriter
         of such public offering the inclusion of all of the Registrable Stock
         and Founder Registrable Stock, requested for inclusion pursuant to this
         Section 2 would interfere with the successful marketing of a smaller
         number of shares to be offered, then the number of shares of
         Registrable Stock and Founder Registrable Stock to be included in the
         Offering shall be reduced to the required level with the participation
         in such offering to be reduced pro rata among the Holders requesting
         such registration, based upon the number of shares of Registrable Stock
         and Founder Registrable Stock owned by such Holders. The Company shall
         be entitled to include in any Registration Statement referred to in
         this Section 2, for sale in accordance with the method of disposition
         specified by the Initiating Holders, shares of Common Stock for the
         Company's own account, except as and to the extent that, in the opinion
         of the managing underwriter, if any, such inclusion would adversely
         affect the marketing of the Registrable Stock and Founder Registrable
         Stock to be sold. Except for registration statements on Form S-4, S-8
         or any successors thereto, the Company will not file with the
         Commission any other registration statement with respect to its Common
         Stock, whether for its own account or that of other stockholders, from
         the date of receipt of a notice from the Initiating Holders pursuant to
         this Section 2 until the completion of the period of distribution of
         the registration contemplated thereby.

                  (d) So long as the Founder is the Chief Executive Officer or a
         director of the Company, Holders of Founder Registrable Stock shall not
         sell in the aggregate more than 675,000 shares of Common Stock (which
         amount shall be appropriately adjusted for any stock splits, stock
         dividends, recapitalizations or other changes affecting the Common
         Stock after the date of this Agreement) in any registration under this
         Section 2 or Section 4 hereof.

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         3. Incidental Registration. Each time the Company shall determine to
file a Registration Statement in connection with the proposed offer and sale for
money of any of its securities by it or any of its security holders, the Company
will give written notice thereof to all Holders. Upon the written request of one
or more Holder(s) given within twenty (20) days after the giving of any such
notice by the Company, the Company will use its best efforts to cause all such
shares of Registrable Stock and Founder Registrable Stock, the Holders of which
have so requested registration thereof, to be included in such Registration
Statement, all to the extent requisite to permit the sale or other disposition
by the prospective seller or sellers of the Registrable Stock and Founder
Registrable Stock to be so registered. If the Registration Statement is to cover
an underwritten distribution, the Company shall use its best efforts to cause
the Registrable Stock and Founder Registrable Stock requested for inclusion
pursuant to this Section 3 to be included in the underwriting on the same terms
and conditions as the securities otherwise being sold through the underwriters.
If, in the good faith judgment of the managing underwriter of such public
offering, the inclusion of all of the Registrable Stock and Founder Registrable
Stock requested for inclusion pursuant to this Section 3 would interfere with
the successful marketing of a smaller number of shares to be offered, then the
number of shares of Registrable Stock, Founder Registrable Stock and other
securities to be included in the offering (except for shares to be issued (i) by
the Company in an offering initiated by the Company or (ii) by any other party
in an offering initiated by such party pursuant to registration rights granted
to such party) shall be reduced to the required level by reducing (down to zero
if so required) the participation of the Holders in such offering (such
reduction to be pro rata among the Holders requesting such registration, based
upon the number of shares of Registrable Stock owned by such Holders); provided,
however, that (i) except in the Company's Initial Public Offering, in no event
shall the participation of the Holders of Registrable Stock and Founder
Registrable Stock be less than thirty-five (35%) percent of such offering, (ii)
so long as the Founder is either the Chief Executive Officer or a director of
the Company, in no event shall the Holders of the Founder Registrable Stock sell
in the aggregate more than 675,000 shares of Common Stock (which amount shall be
appropriately adjusted for any stock splits, stock dividends, recapitalization
or other changes affecting the Common Stock after the date of this Agreement) in
any single distribution and (iii) all shares that are not Registrable Stock or
Founder Registrable Stock and are held by any other person, including, without
limitation, any person who is an employee, officer or director of the Company or
any subsidiary of the Company (other than the Founder) shall first be excluded
from such registration and underwriting before any Registrable Stock or Founder
Registrable Stock are so excluded.

         4. Registration on Form S-3. If at any time after the date hereof (i) a
Holder or Holders request that the Company file a registration statement on Form
S-3 or any successor thereto for a public offering of all or any portion of the
shares of Registrable Stock held by such requesting Holder or Holders, the
reasonably anticipated aggregate proceeds of which would exceed $1,000,000, and
(ii) the Company is a registrant entitled to use Form S-3 or any successor
thereto to register such shares, then the Company shall use its best efforts to
register under the Securities Act on Form S-3 or any successor thereto, for
public sale in accordance with the method of disposition specified in such
notice, the number of shares of Registrable Stock and Founder Registrable Stock
specified in such notice. Whenever the Company is required by this Section 4 to
use its best efforts to effect the registration of Registrable Stock and Founder
Registrable Stock, each of the procedures, requirements and limitations of
Section 2 (including

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but not limited to the requirement that the Company notify all Holders from whom
notice has not been received and provide them with the opportunity to
participate in the offering and the requirement of subparagraph (b)) shall apply
to such registration; provided, however, that there shall be no limitation on
the number of registrations on Form S-3 which may be requested and obtained
under this Section 4; and provided, further, however, that the $10,000,000
minimum dollar amount set forth in the first sentence of Section 2(a) shall not
apply to any registration on Form S-3 which may be requested and obtained under
this Section 4.

         5. Registration Procedures. If and whenever the Company is required by
the provisions of Section 2, 3 or 4 hereof to effect the registration of shares
of Registrable Stock or Founder Registrable Stock under the Securities Act, the
Company will, at its expense, as expeditiously as possible:

                  (a) In accordance with the Securities Act and the rules and
         regulations of the Commission, prepare and file with the Commission a
         Registration Statement with respect to the Registrable Stock or Founder
         Registrable Stock and use its best efforts to cause such Registration
         Statement to become and remain effective until the Registrable Stock or
         Founder Registrable Stock covered by such Registration Statement has
         been sold, and prepare and file with the Commission such amendments to
         such Registration Statement and supplements to the prospectus contained
         therein as may be necessary to keep such Registration Statement
         effective and such Registration Statement and prospectus accurate and
         complete until the Registrable Stock or Founder Registrable Stock
         covered by such Registration Statement has been sold;

                  (b) If the offering is to be underwritten in whole or in part,
         enter into a written underwriting agreement in form and substance
         reasonably satisfactory to the managing underwriter, if any, of the
         public offering and the Holders participating in such offering;

                  (c) Furnish to the participating Holders and to the
         underwriters such reasonable number of copies of the Registration
         Statement, preliminary prospectus, final prospectus and such other
         documents as such underwriters and participating Holders may reasonably
         request in order to facilitate the public offering of such securities;

                  (d) Use its best efforts to register or qualify the
         Registrable Stock and Founder Registrable Stock covered by such
         Registration Statement under such state securities or blue sky laws of
         such jurisdictions (i) as shall be reasonably appropriate for the
         distribution of the Registrable Stock and Founder Registrable Stock
         covered by such Registration Statement or (ii) as such participating
         Holders and underwriters may reasonably request within twenty (20) days
         following the original filing of such Registration Statement, except
         that the Company shall not for any purpose be required to execute a
         general consent to service of process, to subject itself to taxation,
         or to qualify to do business as a foreign corporation in any
         jurisdiction where it is not so qualified;

                  (e) Notify the Holders participating in such registration,
         promptly after it shall receive notice thereof, of the date and time
         when such Registration Statement and each post-effective amendment
         thereto has become effective or a supplement to any prospectus forming
         a part of such Registration Statement has been filed;

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                  (f) Notify the Holders participating in such registration
         promptly of any request by the Commission or any state securities
         commission or agency for the amending or supplementing of such
         Registration Statement or prospectus or for additional information;

                  (g) Prepare and file with the Commission, promptly upon the
         request of any such participating Holders, any amendments or
         supplements to such Registration Statement or prospectus which, in the
         opinion of counsel representing the Company in such Registration (and
         which counsel is reasonably acceptable to such participating Holders),
         is required under the Securities Act or the rules and regulations
         thereunder in connection with the distribution of the Registrable Stock
         and Founder Registrable Stock by such participating Holders;

                  (h) Prepare and promptly file with the Commission, and
         promptly notify such participating Holders of the filing of, such
         amendments or supplements to such Registration Statement or prospectus
         as may be necessary to correct any statements or omissions if, at the
         time when a prospectus relating to such Registrable Stock and Founder
         Registrable Stock is required to be delivered under the Securities Act,
         any event has occurred as the result of which any such prospectus or
         any other prospectus as then in effect would include an untrue
         statement of a material fact or omit to state any material fact
         required to be stated therein or necessary to make the statements
         therein not misleading;

                  (i) In case any of such participating Holders or any
         underwriter for any such Holders is required to deliver a prospectus at
         a time when the prospectus then in circulation is not in compliance
         with the Securities Act or the rules and regulations of the Commission,
         prepare promptly upon request such amendments or supplements to such
         Registration Statement and such prospectus as may be necessary in order
         for such prospectus to comply with the requirements of the Securities
         Act and such rules and regulations;

                  (j) Advise such participating Holders, promptly after it shall
         receive notice or obtain knowledge of the issuance of any stop order by
         the Commission or any state securities commission or agency suspending
         the effectiveness of such Registration Statement or the initiation or
         threatening of any proceeding for that purpose and promptly use its
         best efforts to prevent the issuance of any stop order or to obtain its
         withdrawal if such stop order should be issued;

                  (k) At the request of any such participating Holder (i)
         furnish to such Holder on the effective date of the Registration
         Statement or, if such registration includes an underwritten public
         offering, at the closing provided for in the underwriting agreement, an
         opinion, dated such date, of the counsel representing the Company for
         the purposes of such registration, addressed to the underwriters, if
         any, and to the Holder or Holders making such request, covering such
         matters with respect to the registration statement, the prospectus and
         each amendment or supplement thereto, proceedings under state and
         Federal securities laws, other matters relating to the Company, the
         securities being registered and the offer and sale of such securities
         as are customarily the subject of

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         opinions of issuer's counsel provided to underwriters in underwritten
         public offerings and (ii) use its best efforts to furnish to such
         Holder letters dated each such effective date and such closing date,
         from the independent certified public accountants of the Company,
         addressed to the underwriters, if any, and to the Holder or Holders
         making such request, stating that they are independent certified public
         accountants within the meaning of the Securities Act and dealing with
         such matters as the underwriters may request, or, if the offering is
         not underwritten, that in the opinion of such accountants the financial
         statements and other financial data of the Company included in the
         Registration Statement or the prospectus or any amendment or supplement
         thereto comply in all material respects with the applicable accounting
         requirements of the Securities Act, and additionally covering such
         other financial matters, including information as to the period ending
         not more than five (5) business days prior to the date of such letter
         with respect to the Registration Statement and prospectus, as such
         requesting Holder or Holders may reasonably request; and

                  (l) Use its best efforts to ensure the obtaining of all
         necessary approvals from the NASD.

         6. Expenses.

                  (a) With respect to each registration effected pursuant to
         Section 2, 3 or 4 hereof, all fees, costs and expenses of and
         incidental to such registration and the public offering in connection
         therewith shall be borne by the Company; provided, however, (i) that
         Holders and other holders of the Company's stock participating in any
         such registration shall bear their pro rata share of the underwriting
         discounts and selling commissions, and (ii) any such fee, cost or
         expense which does not constitute a fee, cost or expense customary in
         such a registration and which is attributable solely to one (1) Holder
         or other holder of the Company's stock participating in any such
         registration shall be borne by that holder or Holder.

                  (b) The fees, costs and expenses of registration to be borne
         as provided in paragraph (a) above, shall include, without limitation,
         all registration, filing and NASD fees, printing expenses, fees and
         disbursements of counsel and accountants for the Company, fees and
         disbursements of counsel for the underwriter or underwriters of such
         securities (if the Company and/or selling security holders are
         otherwise required to bear such fees and disbursements), all legal fees
         and disbursements and other expenses of complying with state securities
         or blue sky laws of any jurisdictions in which the securities to be
         offered are to be registered or qualified, reasonable fees and
         disbursements of one counsel for the selling Holders and the other
         holders of the Company's stock and the premiums and other costs of
         policies of insurance insuring the Company against liability arising
         out of such public offering.

         7. Indemnification and Contribution.

                  (a) To the fullest extent permitted by law, the Company will
         indemnify and hold harmless each Holder, whether or not such Holder's
         shares of Registrable Stock are included in a Registration Statement
         pursuant to the provisions of this Agreement, and

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         any underwriter (as defined in the Securities Act) for such Holder, and
         any Person who controls such Holder or such underwriter within the
         meaning of the Securities Act, and each of their successors, from and
         against, and will reimburse such Holder and each such underwriter and
         controlling Person with respect to, any and all claims, actions,
         demands, losses, damages, liabilities, costs and expenses to which such
         Holder or any such underwriter or controlling Person may become subject
         under the Securities Act or otherwise, insofar as such claims, actions,
         demands, losses, damages, liabilities, costs or expenses arise out of
         or are based upon any untrue statement or allegedly untrue statement of
         any material fact contained in such Registration Statement, any
         prospectus contained therein or any amendment or supplement thereto, or
         arise out of or are based upon the omission or alleged omission to
         state therein a material fact required to be stated therein or
         necessary to make the statements therein not misleading or arise out of
         any violation by the Company of any rule or regulation under the
         Securities Act applicable to the Company and relating to action or
         inaction required of the Company in connection with such registration;
         provided, however, that the Company will not be liable in any such case
         to the extent that any such claim, action, demand, loss, damage,
         liability, cost or expense arises out of or is based upon an untrue
         statement or alleged untrue statement or omission or alleged omission
         so made in reliance upon and in conformity with information furnished
         by or on behalf of any such Holder, such underwriter or controlling
         Person in writing specifically for use in the preparation thereof, and
         provided, further, that this indemnity shall not be deemed to relieve
         any underwriter of any of its due diligence obligations; and provided,
         further, that if any claim, action, demand, loss, damage, liability,
         cost or expense arises out of or is based upon an untrue statement or
         alleged untrue statement or omission or alleged omission contained in
         any preliminary prospectus which did not appear in the final prospectus
         and if the Holder delivered a copy of the preliminary prospectus to the
         person alleging damage and failed to deliver a copy of the final
         prospectus to such persons, the Company shall not be liable with
         respect to the claims of such person.

                  (b) Each Holder of shares of Registrable Stock which are
         included in a Registration pursuant to the provisions of this Agreement
         will, severally and not jointly, indemnify and hold harmless the
         Company from and against, and will reimburse the Company with respect
         to, any and all losses, damages, liabilities, costs or expenses to
         which the Company may become subject under the Securities Act or
         otherwise, to the extent that any such loss, damage, liability, cost or
         expense arises out of or is based upon any untrue or alleged untrue
         statement of any material fact contained therein or any amendment or
         supplement thereto, or arises out of or is based upon any omission or
         alleged omission to state therein a material fact required to be stated
         therein or necessary to make the statements therein not misleading, in
         each case to the extent, but only to the extent that such untrue
         statement or alleged untrue statement or omission or alleged omission
         was so made in reliance upon and in conformity with written information
         furnished by or on behalf of such Holder for use in the preparation
         thereof, provided, that, the liability of each Holder hereunder shall
         not, in any event. exceed the proceeds received by such Holder from the
         sale of shares of Registrable Stock covered by a Registration
         Statement; and provided, further, that this indemnity shall not be
         deemed to relieve any underwriter of any of its due diligence
         obligations.

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                  (c) Promptly after receipt by a party to be indemnified
         pursuant to the provisions of paragraph (a) or (b) of this Section 7
         (an "indemnified party") of actual knowledge or notice of the
         commencement of any action involving the subject matter of the
         foregoing indemnity provisions, such indemnified party will, if a claim
         thereof is to be made against the indemnifying party pursuant to the
         provisions of paragraph (a) or (b), notify the indemnifying party of
         the commencement thereof; but the omission so to notify the
         indemnifying party will not relieve it from any liability which it may
         have to an indemnified party otherwise than under this Section 7 and
         shall not relieve the indemnifying party from liability under this
         Section 7 unless such indemnifying party is prejudiced by such
         omission. In case such action is brought against any indemnified party
         and it notifies the indemnifying party of the commencement thereof, the
         indemnifying party shall have the right to participate in, and, to the
         extent that it may wish, jointly with any other indemnifying party
         similarly notified, to assume the defense thereof, with counsel
         reasonably satisfactory to such indemnified party, and after notice
         from the indemnifying party to such indemnified party of its election
         so to assume the defense thereof, the indemnifying party will not be
         liable to such indemnified party pursuant to the provisions of such
         paragraph (a) and (b) for any legal or other expense subsequently
         incurred by such indemnified party in connection with the defense
         thereof other than reasonable costs of investigation. No indemnifying
         party shall be liable to an indemnified party for any settlement of any
         action or claim without the consent of the indemnifying party; no
         indemnifying party may unreasonably withhold its consent to any such
         settlement. No indemnifying party will consent to entry of any judgment
         or enter into any settlement which does not include as an unconditional
         term thereof the giving by the claimant or plaintiff to such
         indemnified party of a release from all liability in respect to such
         claim or litigation.

                  (d) In order to provide for just and equitable contribution to
         joint liability under the Securities Act in any case in which either
         (i) any Holder exercising rights under this Agreement, or any
         controlling person of any such Holder, makes a claim for
         indemnification pursuant to this Section 7 but it is judicially
         determined (by the entry of a final judgment or decree by a court of
         competent jurisdiction and the expiration of time to appeal or the
         denial of the last right of appeal) that such indemnification may not
         be enforced in such case notwithstanding the fact that this Section 7
         provides for indemnification in such case, or (ii) contribution under
         the Securities Act may be required on the part of any such selling
         Holder or any such controlling person in circumstances for which
         indemnification is provided under this Section 7; then, and in each
         such case, the Company and such Holder will contribute to the aggregate
         losses, claims, damages or liabilities to which they may be subject
         (after contribution from others) in such proportion as is appropriate
         to reflect the relative fault of the indemnifying party on the one hand
         and of the indemnified party on the other in connection with the
         violation(s) that resulted in such loss, claim, damage or liability, as
         well as any other relevant equitable considerations. The relative fault
         of the indemnifying party and of the indemnified party shall be
         determined by a court of law by reference to, among other things,
         whether the untrue or alleged untrue statement of a material fact or
         the omission to state a material fact relates to information supplied
         by the indemnifying party or by the indemnified party and the parties'
         relative intent, knowledge, access to information and

                                      -10-
<PAGE>   11
         opportunity to correct or prevent such statement or omission; provided,
         however, that, in any such case; (A) no such Holder will be required to
         contribute any amount in excess of the public offering price, less
         underwriting discounts and commissions, of all such Registrable Stock
         offered and sold by such Holder pursuant to such registration
         statement; and (B) no person or entity guilty of fraudulent
         misrepresentation (within the meaning of Section 11(f) of the
         Securities Act) will be entitled to contribution from any person or
         entity who was not guilty of such fraudulent misrepresentation.

                  (e) Survival. The obligations of the Company and Holders under
         this Section 7 shall survive until the fifth anniversary of the
         completion of any offering of Registrable Stock in a registration
         statement, regardless of the expiration of any statutes of limitation
         or extensions of such statutes.

         8. Reporting Requirements Under Securities Exchange Act of 1934. When
it is first legally required to do so, the Company shall register its Common
Stock under Section 12 of the Exchange Act and shall keep effective such
registration and shall timely file such information, documents and reports as
the Commission may require or prescribe under Section 13 of the Exchange Act.
From and after the effective date of the first Registration Statement filed by
the Company, the Company shall use its best efforts to (whether or not it shall
then be required to do so) timely file such information, documents and reports
as the Commission may require or prescribe under Section 13 or 15(d) (whichever
is applicable) of the Exchange Act. Immediately upon becoming subject to the
reporting requirements of either Section 13 or 15(d) of the Exchange Act, the
Company shall forthwith upon request furnish any Holder (i) a written statement
by the Company that it has complied with such reporting requirements, (ii) a
copy of the most recent annual or quarterly report of the Company, and (iii)
such other reports and documents filed by the Company with the Commission as
such Holder may reasonably request in availing itself of an exemption for the
sale of Registrable Stock without registration under the Securities Act. The
Company acknowledges and agrees that the purposes of the requirements contained
in this Section 8 are (a) to enable any such Holder to comply with the current
public information requirement contained in Paragraph (c) of Rule 144 under the
Securities Act should such Holder ever wish to dispose of any of the securities
of the Company acquired by it without registration under the Securities Act in
reliance upon Rule 144 (or any other similar or successor exemptive provision),
and (b) to qualify the Company for the use of Registration Statements on Form
S-3. In addition, the Company shall take such other measures and file such other
information, documents and reports, as shall hereafter be required by the
Commission as a condition to the availability of Rule 144 under the Securities
Act (or any similar or successor exemptive provision hereafter in effect) and
the use of Form S-3. The Company also covenants to use its best efforts, to the
extent that it is reasonably within its power to do so, to qualify for the use
of Form S-3. From and after the effective date of the first Registration
Statement filed by the Company, the Company agrees to use its best efforts to
facilitate and expedite transfers of Registrable Stock pursuant to Rule 144
under the Securities Act (or any similar or successor exemptive provision
hereafter in effect), which efforts shall include timely notice to its transfer
agent to expedite such transfers of Registrable Stock.

         9. Stockholder Information. The Company may require each Holder of
Registrable Stock as to which any registration is to be effected pursuant to
this Agreement to furnish the Company in a timely manner such information with
respect to such Holder and the distribution

                                      -11-
<PAGE>   12
of such Registrable Stock as the Company may from time to time reasonably
request in writing and as shall be required by law or by the Commission in
connection therewith.

         10. Lock-Up Agreements.

                  (a) Restrictions on Public Sale by the Company. The Company
         agrees not to effect any public sale or other distribution of its
         equity securities, or any securities convertible into or exchangeable
         or exercisable for such equity securities, during the period, not to
         exceed one hundred eighty (180) days (as requested by the managing
         underwriter), following the effective date of the Initial Public
         Offering, or ninety (90) days following the effective date of any other
         underwritten public offering of securities of the Company, except in
         connection with any such underwritten offering and except for equity
         securities issued pursuant to employee stock option or employee stock
         purchase plans or in conjunction with any merger or consolidation with,
         or acquisition of the stock or assets of, any other entity.

                  (b) Restrictions on Public Sale by the Holders. Each Holder
         agrees that it will not, to the extent requested by the Company and the
         managing underwriter of such offering, sell or otherwise dispose of any
         equity securities of the Company, including any sale pursuant to Rule
         144, during a period specified by the Company and such underwriter (not
         to exceed one hundred eighty (180) days after the effective date of the
         Initial Public Offering or ninety (90) days after any other
         underwritten offering), except in conjunction with such underwritten
         offering; provided, that, each officer and director of the Company
         shall enter into similar agreements.

         11. Notices. Any notice required or permitted to be given hereunder
shall be in writing and shall be deemed to be properly given when sent by
registered or certified mail, return receipt requested, by Federal Express, DHL
or other guaranteed overnight delivery service or by facsimile transmission,
addressed as follows:

             If to the Company:          Sitara Networks, Inc.
                                         60 Hickory Drive
                                         Waltham, MA 02154
                                         Attention:  President
                                         Telecopier:  (781) 890-8042

             with a copy to:             McDermott, Will & Emery
                                         28 State Street
                                         Boston, MA  02109
                                         Attention:  Arthur I. Anderson, P.C.
                                         Telecopier:  (617) 535-3800

             If to the Founder:          Malik Z. Khan
                                         240 Western Avenue
                                         Sherborn, MA 01770

                                      -12-
<PAGE>   13
             If to any Investor:         To the address of such Investor set
                                         forth on Schedule RRA-1 hereto

and if to any other Holder at such Holder's address for notice as set forth in
the register maintained by the Company, or, as to any of the foregoing, to such
other address as any such party may give the others notice of pursuant to this
Section, provided that a change of address shall only be effective upon receipt.

         All notices, requests, consents and other communications hereunder
shall be deemed to have been received (i) if by hand, at the time of delivery
thereof to the receiving party at the address of such party set forth above or
as so designated, (ii) if made by telecopy or facsimile transmission, at the
time that receipt thereof has been acknowledged by electronic confirmation or
otherwise, (iii) if sent by overnight courier, on the day such notice is
delivered by the courier service, or (iv) if sent by registered or certified
mail, on the fifth business day following the day such mailing is made.

         12. Governing Law. This Agreement shall be governed by, and construed
in accordance with, the substantive laws of the Commonwealth of Massachusetts
(without regard to conflict of laws provisions).

         13. Waivers; Amendments. No waiver of any right hereunder by any party
shall operate as a waiver of any other right, or of the same right with respect
to any subsequent occasion for its exercise, or of any right to damages. No
waiver by any party of any breach of this Agreement shall be held to constitute
a waiver of any other breach or a continuation of the same breach. All remedies
provided by this Agreement are in addition to all other remedies provided by
law. This Agreement may not be amended except by a writing executed by the
Company and (i) the Holders of at least sixty (60%) percent of the Registrable
Stock and the securities convertible into, exchangeable for or exercisable for
Registrable Stock (calculated on an as converted, exchanged or exercised basis),
and (ii) if the amendment affects adversely any of the rights of the Founder
hereunder, by the Founder as well.

         14. Other Registration Rights. The Company shall not grant to any third
party any registration rights more favorable than any of those contained herein,
or which would interfere with or delay the exercise by the Holders of their
registrations rights hereunder, so long as any of the registration rights under
this Agreement remains in effect, unless approved by Holders of at least sixty
(60%) percent of the shares of Registrable Stock, which approval may require
that such rights be granted only pursuant to an amendment or restatement of this
Agreement.

         15. Successors and Assigns. This Agreement shall be binding upon and
shall inure to the benefit of the respective legal representatives, successors
and assigns of the parties hereto; provided, however, that the registration
rights conferred herein shall only inure to the benefit of a transferee of
Registrable Stock if (i) there is transferred to such transferee at least ten
(10%) percent of the Registrable Stock originally issued by the Company to the
direct or indirect transferor of such transferee, (ii) such transferee is a
partner, shareholder, member or affiliate of a party hereto; and in each case
such transferee becomes a party to this Agreement by signing a counterpart
hereof, at which point such transferee shall become an "Investor" for the
purposes of this Agreement, or (iii) such transferee is a member of the family
(i.e., spouse, sibling, spouse's

                                      -13-
<PAGE>   14
sibling, child (natural or adopted), stepchild, grandchild, parent, grandparent
or any other lineal ancestor or descendent) of a party or partner, shareholder,
member or affiliate of a party hereto; provided, however, that no expansion of
the definition of Holders set forth above shall be effected by this Section 15.

         16. Counterparts. This Agreement 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.

         17. Prior Understandings. This Agreement represents the complete
agreement of the parties with respect to the transactions contemplated hereby
and supersedes all prior agreements and understandings.

         18. Headings. Headings in this Agreement are included for reference
only and shall have no effect upon the construction or interpretation of any
part of this Agreement.

         19. Severability. If any provision of this Agreement shall be held to
be illegal, invalid or unenforceable, such illegality, invalidity or
unenforceability shall attach only to such provision and shall not in any manner
affect or render illegal, invalid or unenforceable any other provision of this
Agreement, and this Agreement shall be carried out as if any such illegal,
invalid or unenforceable provision were not contained herein.



                  [Remainder of Page Intentionally Left Blank]



                                      -14-
<PAGE>   15
         IN WITNESS WHEREOF, the Company has caused this Agreement to be
executed by a duly authorized officer, and each Investor has duly executed this
Agreement (or has caused it to be executed by a duly authorized officer,
partner, trustee or agent, as the case may be), as of the date first above
recited.





ATTEST:                              COMPANY:

                                     SITARA NETWORKS, INC.



/s/ Arthur Anderson                  By: /s/ Malik Z. Khan
-------------------                      --------------------------
Secretary                                    Malik Z. Khan, President




                                     FOUNDER:



                                     /s/ Malik Z. Khan
                                     ------------------------------
                                         Malik Z. Khan



                                     INVESTORS:



                                     ONELIBERTY FUND III, L.P.

                                     By: One Liberty Partners III, L.P.,
                                     its general partner



                                     By: /s/ Edwin M. Kania
                                         --------------------------
                                         Edwin M. Kania, Jr.
                                         One Liberty Square
                                         Boston,  MA 02109
<PAGE>   16
                                     FW VENTURES IV L.P.


                                     By: /s/ David Brown
                                         --------------------------
                                     Name:  David Brown
                                     Title:
                                     201 Main Street, Suite 3100
                                     Fort Worth,  TX  76102


                                     ESSEX PRIVATE PLACEMENT FUND III-A,
                                     LIMITED PARTNERSHIP.

                                     By:  Essex Investment Management Company,
                                     LLC, its general partner


                                     By: /s/ Susan P. Stickells
                                         --------------------------
                                     Name:   Susan P. Stickells
                                     Title:  Principal
                                     125 High Street, 29th Floor
                                     Boston,  MA 02110


                                     ESSEX PRIVATE PLACEMENT FUND III-B,
                                     LIMITED PARTNERSHIP.

                                     By:  Essex Investment Management Company,
                                     LLC,its general partner


                                     By: /s/ Susan P. Stickells
                                         --------------------------
                                     Name:   Susan P. Stickells
                                     Title:  Principal
                                     125 High Street, 29th Floor
                                     Boston,  MA 02110



                                     ESSEX HIGH TECHNOLOGY FUND L.P.

                                     By:  Essex Investment Management Company,
                                     LLC, its general partner


                                     By: /s/ Susan P. Stickells
                                         --------------------------
                                     Name:   Susan P. Stickells
                                     Title:  Principal
                                     125 High Street, 29th Floor
                                     Boston,  MA 02110
<PAGE>   17
                                     TWP SITARA INVESTORS


                                     By: /s/ David A. Baylor
                                         --------------------------
                                     Name:  David A. Baylor
                                     Title: Managing Partner


                                     TAILWIND CAPITAL PARTNERS 2000, L.P.

                                     By:  Thomas Weisel Capital Partners LLC,
                                     General Partner


                                     By: /s/ David Baylor
                                         --------------------------
                                     Name:  David Baylor
                                     Title: General Counsel



                                     /s/ Barry Davis
                                     ------------------------------
                                         Barry Davis


                                     NEW ENTERPRISE ASSOCIATES VII, LP


                                     By: /s/ Arthur J. Marks
                                         --------------------------
                                     Name:   Arthur J. Marks


                                     NEA PRESIDENTS' FUND, L.P.


                                     By: /s/ Arthur J. Marks
                                         --------------------------
                                     Name:   Arthur J. Marks


                                     PRISM VENTURE PARTNERS I, L.P.

                                     By:  Prism Investment Partners, L.L.C.,
                                     its general partner


                                     By: /s/ Robert Fleming
                                         --------------------------
                                     Name:   Robert Fleming
                                     100 Lowder Brook Drive
                                     Suite 2500
                                     Westwood,  MA  02090
<PAGE>   18
                                     MFS SERIES TRUST I on behalf of
                                     MFS New Discovery Fund ("NDF")
                                     ($4,841,584.65; 743,715 shares)
                                     Nominee:  Clump & Co.
                                     Nominee ID:  04-3208074
                                     Tax ID:  04-3339400

                                     By: /s/ Ellen Moynihan
                                         --------------------------
                                     Name:   Ellen Moynihan
                                     Title:  Assistant Treasurer


                                     MFS/SUN LIFE SERIES TRUST on behalf
                                     of MFS New Discovery Series ("NWD")
                                     ($482,391; 74,100 shares)
                                     Nominee:  Inletbluff & Co.
                                     Nominee ID:  04-3409455
                                     Tax ID:  04-3417488

                                     By: /s/ Ellen Moynihan
                                         --------------------------
                                     Name:   Ellen Moynihan
                                     Title:  Assistant Treasurer


                                     MFS VARIABLE INSURANCE TRUST on
                                     behalf of MFS New Discovery Series ("VND")
                                     ($276,024; 42,400 shares)
                                     Nominee:  Newwind & Co.
                                     Nominee ID:  04-3409369
                                     Tax ID:  04-3417481

                                     By: /s/ Ellen Moynihan
                                         --------------------------
                                     Name:   Ellen Moynihan
                                     Title:  Assistant Treasurer
<PAGE>   19
                                     MFS SERIES TRUST I on behalf of
                                     MFS Technology Fund ("SCT")
                                     ($400,000.44; 61,444 shares)
                                     Nominee:  Distinguish & Co.
                                     Nominee ID:  04-3208197
                                     Tax ID:  04-3339406

                                     By: /s/ Ellen Moynihan
                                         --------------------------
                                     Name:   Ellen Moynihan
                                     Title:  Assistant Treasurer


                                     VAN WAGONER CAPITAL MANAGEMENT

                                     By: /s/ Audrey Lam
                                         --------------------------
                                     Name:   Audrey Lam
                                     Title:  Managing Director
                                     345 California Street, Suite 2450
                                     San Francisco,  CA  94104


                                     BT INVESTMENT PARTNERS, INC.

                                     By: /s/ Kristine Cicardo
                                         --------------------------
                                     Name:   Kristine Cicardo
                                     Title:  Director


                                     CHARLES RIVER PARTNERSHIP VII, L.P.

                                     By: /s/ Michael Zak
                                         --------------------------
                                     Name:   Michael Zak
                                     Title:  General Partner
                                     1000 Winter Street, Suite 3300
                                     Waltham,  MA  02154


                                     SIEMENS SERVICES, INC.

                                     By: /s/ Michael Rowan
                                         --------------------------
                                     Name:   Michael Rowan
                                     Title:  Vice President
                                     Chase Manhattan Center, Suite 1402
                                     1201 Market Street
                                     Wilmington, DE  19801
<PAGE>   20
                                     SIEMENS SERVICES, INC.

                                     By: /s/ Christine Krzyzarnski
                                         --------------------------
                                     Name:   Christine Krzyzarnski
                                     Title:  Vice President
                                     Chase Manhattan Center, Suite 1402
                                     1201 Market Street
                                     Wilmington, DE  19801


                                     /s/ Dipak Rastogi
                                     ------------------------------
                                         Dipak Rastogi


                                     /s/ Audrey M. Rastogi
                                     ------------------------------
                                         Audrey M. Rastogi


                                     /s/ John Halligan
                                     ------------------------------
                                         John Halligan


                                     /s/ Andy Fox
                                     ------------------------------
                                         Andy Fox


                                     /s/ Michael Bassinger
                                     ------------------------------
                                         Michael Bassinger


                                     /s/ Rhys Williams
                                     ------------------------------
                                         Rhys Williams
                                         General Partner, SIVO G.P.


                                     /s/ Manny Fernandez
                                     ------------------------------
                                         Manny Fernandez


                                     SI VENTURE FUND II, L.P.

                                     By: /s/ Manny Fernandez
                                         --------------------------
                                     Name:   Manny Fernandez
                                     Title:  Managing Director
<PAGE>   21
                                     ANGLO AMERICAN SECURITY FUND, L.P.

                                     By: /s/ John S. Grace
                                         --------------------------
                                     Name:   John S. Grace
                                     Title:  General Partner


                                     CABIN INTERIORS, LP
                                     By: Cabin Interiors, Inc., its general
                                     partner

                                     By: /s/ John S. Grace
                                         --------------------------
                                     Name:   John S. Grace
                                     Title:  President


                                     DIVERSIFIED LONG TERM GROWTH FUND, L.P.
                                     By: Associated Asset Management, Inc.
                                     its general partner

                                     By: /s/ John S. Grace
                                         --------------------------
                                     Name:   John S. Grace
                                     Title:  Co-Chairman


                                     DRAKE ASSOCIATES, L.P.
                                     By: Associated Asset Management, Inc.
                                     its general partner

                                     By: /s/ John S. Grace
                                         --------------------------
                                     Name:   John S. Grace
                                     Title:  Co-Chairman


                                     STERLING GRACE CAPITAL MANAGEMENT, LP.
                                     By: Sterling Grace Corporation,
                                     its general partner

                                     By: /s/ John S. Grace
                                         --------------------------
                                     Name:   John S. Grace
                                     Title:  President
<PAGE>   22
                                     GRACE-ARTEL INVESTORS, INC.


                                     By: /s/ Oliver R. Grace
                                         --------------------------
                                     Name:   Oliver R. Grace
                                     Title:  Chairman


                                     THE SOG FUND LP
                                     By: The Special Opportunities Group, LLC
                                     its managing general partner

                                     By: /s/ Christopher G. Miller
                                         --------------------------
                                     Name:   Christopher G. Miller
                                     Title:  Chief Executive Officer


                                     THE SOG FUND II LP
                                     By:  The Special Opportunities Group, LLC
                                     its managing general partner

                                     By: /s/ Christopher G. Miller
                                         --------------------------
                                     Name:   Christopher G. Miller
                                     Title:  Chief Executive Officer
<PAGE>   23
                                 SCHEDULE RRA-1

<TABLE>
<CAPTION>
    INVESTOR & ADDRESS                   NUMBER OF            NUMBER OF           NUMBER OF          NUMBER OF
    ------------------                  SHARES  OF             SHARES              SHARES             SHARES
                                         SERIES A            OF SERIES B         OF SERIES C       OF SERIES D
                                      PREFERRED STOCK      PREFERRED STOCK     PREFERRED STOCK    PREFERRED STOCK
                                      ---------------      ---------------     ---------------    ---------------
<S>                                   <C>                  <C>                 <C>                <C>
Charles River Partnership                 2,352,941              785,714            359,090              --
VII, L.P.
1000 Winter Street
Suite 3300
Waltham, MA 02154
Attn:  Michael Zak
Telecopier:  (617) 487-7005

OneLiberty Fund III, L.P.
One Liberty Square                        2,352,941              785,714            359,090              --
Boston, MA 02109
Attn:  Edward Kania
Telecopier: (617) 338-4362

New Enterprise Associates
VII, LP                                     958,824            1,785,715            318,710              --
1119 St. Paul Street
Baltimore, MD 21202
Attn:  Nancy Dorman
Telecopier:

Prism Venture Partners I, L.P.
100 Lowder Brook Drive                           --            1,428,571            163,441              --
Suite 2500
Westwood, MA 02090
Attn:  Robert Fleming
</TABLE>


<TABLE>
<CAPTION>
    INVESTOR & ADDRESS                    NUMBER OF               NUMBER OF              NUMBER OF
    ------------------                     SHARES                  SHARES                 SHARES
                                         OF SERIES E             OF SERIES F             OF SERIES G
                                       PREFERRED STOCK          PREFERRED STOCK        PREFERRED STOCK
                                       ---------------          ---------------        ---------------
<S>                                    <C>                      <C>                    <C>
Charles River Partnership                   142,144                   --
VII, L.P.
1000 Winter Street
Suite 3300
Waltham, MA 02154
Attn:  Michael Zak
Telecopier:  (617) 487-7005

OneLiberty Fund III, L.P.
One Liberty Square                          142,144                   --
Boston, MA 02109
Attn:  Edward Kania
Telecopier: (617) 338-4362

New Enterprise Associates
VII, LP                                     122,263                   --
1119 St. Paul Street
Baltimore, MD 21202
Attn:  Nancy Dorman
Telecopier:

Prism Venture Partners I, L.P.
100 Lowder Brook Drive                       64,697                   --
Suite 2500
Westwood, MA 02090
Attn:  Robert Fleming
</TABLE>
<PAGE>   24
                            SCHEDULE RRA-1 CONTINUED

<TABLE>
<CAPTION>
    INVESTOR & ADDRESS                     NUMBER OF           NUMBER OF          NUMBER OF           NUMBER OF
    ------------------                     SHARES OF           SHARES OF          SHARES OF           SHARES OF
                                           SERIES A             SERIES B           SERIES C            SERIES D
                                        PREFERRED STOCK      PREFERRED STOCK    PREFERRED STOCK    PREFERRED STOCK
                                        ---------------      ---------------     ---------------    ---------------
<S>                                     <C>                  <C>                <C>                <C>
NEA Presidents' Fund, L.P.                   41,176                   --                --                 --
1119 St. Paul Street
Baltimore, MD 21202
Attn:  Nancy Dorman

M/C Investors L.L.C                         588,235              178,572            87,729                 --
75 State Street
Boston, MA 02109
Attn: Jim Wade
Telecopier:

Sharon Sisskind                             117,647               17,857            15,503                 --
70 Barnstable Road
West Newton, MA 02165

K. Paul Singh                                58,825               17,857             8,773                 --
Primus Telecommunications
1700 Old Meadow Road
3rd Floor
McLean, VA 22102

Intel Corporation                                --                   --                --            787,402
2200 Mission College Blvd.
Santa Clara, CA 95052

FW Ventures IV L.P.                              --                   --                --                 --
201 Main Street, Suite 3100
Fort Worth, TX 76102

Essex High Technology Fund L.P.                  --                   --                --                 --
125 High Street, 29th Floor
Boston, MA 02110
Attn:  Susan Stickells
</TABLE>

<TABLE>
<CAPTION>
    INVESTOR & ADDRESS                     NUMBER OF             NUMBER OF          NUMBER OF
    ------------------                     SHARES OF             SHARES OF          SHARES OF
                                           SERIES E              SERIES F           SERIES G
                                        PREFERRED STOCK       PREFERRED STOCK     PREFERRED STOCK
                                        ---------------       ---------------     ---------------
<S>                                     <C>                   <C>                 <C>
NEA Presidents' Fund, L.P.                    3,896                   --
1119 St. Paul Street
Baltimore, MD 21202
Attn:  Nancy Dorman

M/C Investors L.L.C                           34,727                  --
75 State Street
Boston, MA 02109
Attn: Jim Wade
Telecopier:

Sharon Sisskind                                6,137                  --
70 Barnstable Road
West Newton, MA 02165

K. Paul Singh                                  3,473                  --
Primus Telecommunications
1700 Old Meadow Road
3rd Floor
McLean, VA 22102

Intel Corporation                                 --                  --
2200 Mission College Blvd.
Santa Clara, CA 95052

FW Ventures IV L.P.                        2,077,922                  --
201 Main Street, Suite 3100
Fort Worth, TX 76102

Essex High Technology Fund L.P.              181,818                 --
125 High Street, 29th Floor
Boston, MA 02110
Attn:  Susan Stickells
</TABLE>
<PAGE>   25
<TABLE>
<CAPTION>
    INVESTOR & ADDRESS                     NUMBER OF          NUMBER OF           NUMBER OF           NUMBER OF
    ------------------                     SHARES OF          SHARES OF           SHARES OF           SHARES OF
                                           SERIES A            SERIES B            SERIES C            SERIES D
                                        PREFERRED STOCK     PREFERRED STOCK     PREFERRED STOCK    PREFERRED STOCK
                                        ---------------     ---------------     ---------------    ---------------
<S>                                     <C>                 <C>                 <C>                <C>
Utility Competitive Advantage                  --                 --                   --                 --
Fund L.P.
2 Wisconsin Circle, Suite 620
Chevy Chase, MD 20815

ABS Employees Venture Fund L.P.                --                 --                   --                 --
1 South Street, 17th Floor
Baltimore, MD 21202

Van Wagoner Capital Management                 --                 --                   --                 --
345 California Street,
Suite 2450
San Francisco, CA 94104

Michael Murray                                 --                 --                   --                 --
D. Alex Brown
101 Federal Street
15th Floor
Boston, MA 02110


Gunjan Sinha                                   --                 --                   --                 --
e-gain
624 East Evelyn Ave
Sunnyvale, CA 94086


Valhalla Capital, LP                           --                 --                   --                 --
10863 Pleasant Hill
Potomac, MD 20854


America Online, Inc.                           --                 --                   --                 --
22000 AOL Way
Dulles, VA 20166
</TABLE>


<TABLE>
<CAPTION>
    INVESTOR & ADDRESS                    NUMBER OF           NUMBER OF           NUMBER OF
    ------------------                    SHARES OF           SHARES OF           SHARES OF
                                           SERIES E            SERIES F            SERIES G
                                        PREFERRED STOCK     PREFERRED STOCK     PREFERRED STOCK
                                        ---------------     ---------------     ---------------
<S>                                     <C>                 <C>                 <C>
Utility Competitive Advantage             779,221                 --
Fund L.P.
2 Wisconsin Circle, Suite 620
Chevy Chase, MD 20815

ABS Employees Venture Fund L.P.           148,874                 --
1 South Street, 17th Floor
Baltimore, MD 21202

Van Wagoner Capital Management            779,221                 --
345 California Street,
Suite 2450
San Francisco, CA 94104

Michael Murray                              2,600                 --
D. Alex Brown
101 Federal Street
15th Floor
Boston, MA 02110


Gunjan Sinha                              129,870                 --
e-gain
624 East Evelyn Ave
Sunnyvale, CA 94086


Valhalla Capital, LP                       64,935                 --
10863 Pleasant Hill
Potomac, MD 20854


America Online, Inc.                     1,038,961                --
22000 AOL Way
Dulles, VA 20166
</TABLE>
<PAGE>   26
<TABLE>
<CAPTION>
    INVESTOR & ADDRESS                     NUMBER OF          NUMBER OF           NUMBER OF           NUMBER OF
    ------------------                     SHARES OF          SHARES OF           SHARES OF           SHARES OF
                                           SERIES A            SERIES B            SERIES C            SERIES D
                                        PREFERRED STOCK     PREFERRED STOCK     PREFERRED STOCK    PREFERRED STOCK
                                        ---------------     ---------------     ---------------    ---------------
<S>                                     <C>                 <C>                 <C>                <C>
Primus Telecommunications Group                --                 --                   --                 --
Inc.
1700 Old Meadow Road
3rd Floor
McLean, VA 22102
Attn:  K. Paul Singh


Presidio Venture Partners, LLC                 --                 --                   --                 --
600 Third Avenue
New York, NY 10016-2001
Attn:  Mr. Seiji Sato


Kenneth W. Slutsky                             --                 --                   --                 --
Sepulveda Capital
920 Manhatten Beach Blvd.
Manhatten Beach, CA 90266


Checchi Family Trust                           --                 --                   --                 --
c/o Kenneth W. Slutsky
Sepulveda Capital
920 Manhatten Beach Blvd.
Manhatten Beach, CA 90266


Robert Kutnick                                 --                 --                   --                 --
3043 Durham-B
Century Village East
Deerfield Beach, Florida 33442


Robert A. Morris                               --                 --                   --                 --
1239 Hillsboro Mile, No. 409
Hillsboro Beach, Florida 33062


David Weiss                                    --                 --                   --                 --
20088 West Key Drive
Boca Raton, Florida 33498


Jeffrey Issac Krantz                           --                 --                   --                 --
21503 Sweetwater Lane South
Boca Raton, Florida 33428
</TABLE>


<TABLE>
<CAPTION>
    INVESTOR & ADDRESS                    NUMBER OF           NUMBER OF           NUMBER OF
    ------------------                    SHARES OF           SHARES OF           SHARES OF
                                           SERIES E            SERIES F            SERIES G
                                        PREFERRED STOCK     PREFERRED STOCK     PREFERRED STOCK
                                        ---------------     ---------------     ---------------
<S>                                     <C>                 <C>                 <C>
Primus Telecommunications Group               --               600,000
Inc.
1700 Old Meadow Road
3rd Floor
McLean, VA 22102
Attn:  K. Paul Singh


Presidio Venture Partners, LLC                --               200,000
600 Third Avenue
New York, NY 10016-2001
Attn:  Mr. Seiji Sato


Kenneth W. Slutsky                            --               100,000
Sepulveda Capital
920 Manhatten Beach Blvd.
Manhatten Beach, CA 90266


Checchi Family Trust                          --               100,000
c/o Kenneth W. Slutsky
Sepulveda Capital
920 Manhatten Beach Blvd.
Manhatten Beach, CA 90266


Robert Kutnick                                --                20,000
3043 Durham-B
Century Village East
Deerfield Beach, Florida 33442


Robert A. Morris                              --                10,000
1239 Hillsboro Mile, No. 409
Hillsboro Beach, Florida 33062


David Weiss                                   --                10,000
20088 West Key Drive
Boca Raton, Florida 33498


Jeffrey Issac Krantz                          --                10,000
21503 Sweetwater Lane South
Boca Raton, Florida 33428
</TABLE>
<PAGE>   27
<TABLE>
<CAPTION>
    INVESTOR & ADDRESS                     NUMBER OF          NUMBER OF           NUMBER OF           NUMBER OF
    ------------------                     SHARES OF          SHARES OF           SHARES OF           SHARES OF
                                           SERIES A            SERIES B            SERIES C            SERIES D
                                        PREFERRED STOCK     PREFERRED STOCK     PREFERRED STOCK    PREFERRED STOCK
                                        ---------------     ---------------     ---------------    ---------------
<S>                                     <C>                 <C>                 <C>                <C>
Andy Stergiades                               --                  --                  --                  --
4205 Intracoastal Drive
Highland Beach, Florida  33487


John P. Cunningham                            --                  --                  --                  --
121 Stonebridge Square
Chappaqua, New York  10515


Scott Broder                                  --                  --                  --                  --
923 NE 24th Street
Boca Raton, Florida  33431]


Ed Iacobucci                                  --                  --                  --                  --
901 South Ocean Blvd.
Delray Beach, FL 33483
</TABLE>

<TABLE>
<CAPTION>
    INVESTOR & ADDRESS                    NUMBER OF           NUMBER OF           NUMBER OF
    ------------------                    SHARES OF           SHARES OF           SHARES OF
                                           SERIES E            SERIES F            SERIES G
                                        PREFERRED STOCK     PREFERRED STOCK     PREFERRED STOCK
                                        ---------------     ---------------     ---------------
<S>                                     <C>                 <C>                 <C>
Andy Stergiades                               --                 10,000
4205 Intracoastal Drive
Highland Beach, Florida  33487


John P. Cunningham                            --                  5,000
121 Stonebridge Square
Chappaqua, New York  10515


Scott Broder                                  --                  5,000
923 NE 24th Street
Boca Raton, Florida  33431]


Ed Iacobucci                                  --                 40,000
901 South Ocean Blvd.
Delray Beach, FL 33483
</TABLE>
<PAGE>   28
                               AMENDMENT NO. 1 TO

                              SITARA NETWORKS, INC.
                      SERIES G CONVERTIBLE PREFERRED STOCK
                               PURCHASE AGREEMENT,

                           SIXTH AMENDED AND RESTATED
                             STOCKHOLDERS AGREEMENT

                                       AND

                           SIXTH AMENDED AND RESTATED
                          REGISTRATION RIGHTS AGREEMENT

                              SEPTEMBER ____, 2000

         WHEREAS, the undersigned, being (i) Sitara Networks, Inc., a Delaware
corporation (the "Company"), (ii) the holders (the "Required Holders") of at
least sixty (60%) percent of the issued and outstanding shares of Series A
Convertible Preferred Stock, $0.00001 par value per share, (the "Series A
Stock"), Series B Convertible Preferred Stock, $0.00001 par value per share (the
"Series B Stock"), Series C Convertible Preferred Stock, $0.00001 par value per
share (the "Series C Stock"), Series D Convertible Preferred Stock, $0.00001 par
value (the "Series D Stock"), Series E Convertible Preferred Stock, $0.00001 par
value per share (the "Series E Stock"), Series F Convertible Preferred Stock,
$0.00001 par value per share (the "Series F Stock"), and Series G Convertible
Preferred Stock, $0.00001 (the "Series G Stock" and together with the Series A
Stock, the Series B Stock, the Series C Stock, the Series D Stock, the Series E
Stock, and the Series F Stock the "Preferred Stock") of the Company, calculated
as a single class (treating all Preferred Stock for all purposes herein as if
converted to Common Stock, par value $.00001 per share ), and (iii) Malik Z.
Khan, in his capacity as the founder of the Company (the "Founder"), desire to
amend (1) that certain Series G Convertible Preferred Stock Purchase Agreement,
dated as of June 16, 2000, by and among the Company and the other parties
thereto (the "Series G Purchase Agreement"), (2) that certain Sixth Amended and
Restated Stockholders Agreement, dated as of June 16, 2000, by and among the
Company and the other parties thereto (the "Stockholders Agreement") and (3)
that certain Sixth Amended and Restated Registration Rights Agreement, dated as
of June 16, 2000 by and among the Company and the other parties thereto (the
"Registration Rights Agreement");

         WHEREAS, Section 6.02 of the Series G Purchase Agreement permits
amendments to such agreement upon the written consent of the Company and the
Required Holders;

         WHEREAS, Section 14 of the Stockholders Agreement permits amendments to
such agreement upon the written consent of the Company, the Required Holders and
the Founder; and

         WHEREAS, Section 13 of the Registration Rights Agreement permits
amendments to such agreement upon the written consent of the Company, the
Required Holders and the Founder;
<PAGE>   29
         NOW, THEREFORE, in consideration of the mutual covenants set forth
herein, the parties hereto agree as follows:

         A.       That, the Series G Purchase Agreement be amended to the extent
set forth below:

                  1. The second sentence of Section 2.03(b) of the Agreement is
         hereby amended and restated in its entirety to read as follows:

                  "Such purchase and sale shall take place at a closing or
                  series of closings (the "Subsequent Closings" and together
                  with the Initial Closing, the "Closing") to be held at the
                  office of Counsel to the Company, 28 State Street, Boston,
                  Massachusetts 02109, at any time or from time to time, through
                  and including October 15, 2000, as may be mutually agreed upon
                  by the Company and such Purchasers."

                  2. The Company is hereby empowered to amend and restate
         Exhibit 2.01A of the Series G Purchase Agreement to reflect any
         additional sales of Series G Stock in any Subsequent Closings.

         B.       That the Stockholders Agreement be amended (i) to the extent
necessary to add any persons who purchase any shares of Series G Stock at any
Subsequent Closing to the Stockholders Agreement as "Investors" thereunder and
(ii) to the extent set forth below:

                  1. The number of shares current issuable under the Company's
         Stock Incentive Program that are excluded from the pre-emptive rights
         set forth in Section 12 of the Stockholders Agreement shall be
         increased by replacing the number "7,200,000" in clause (E) of the
         first sentence of Section 12 of the Stockholders Agreement with the
         number "9,200,000".

         C.       That the Registration Rights Agreement be amended to the
extent necessary to add any persons who purchase any shares of Series G Stock at
any Subsequent Closing to the Registration Rights Agreement as "Investors"
thereunder and to accordingly amend and restate Schedule RRA-1 of the
Registration Rights Agreement.




                            [SIGNATURE PAGES FOLLOW]

                                       2
<PAGE>   30
         IN WITNESS WHEREOF, the undersigned have executed this Amendment No. 1
to the Sitara Networks, Inc. Series G Convertible Preferred Stock Purchase
Agreement, the Sixth Amended and Restated Stockholders Agreement and the Sixth
Amended and Restated Registration Rights Agreement as of the date first written
above.


                                          COMPANY:

                                          SITARA NETWORKS, INC.


                                          By:    /s/ Malik Khan
                                                 -----------------------------
                                          Name:  Malik Khan
                                          Title: President


                                          FOUNDER:

                                          /s/ Malik Khan
                                          Malik Z. Khan


                                          PREFERRED STOCKHOLDERS:

                                          CHARLES RIVER PARTNERSHIP VII, L.P.


                                          By:    /s/ Michael Zak
                                                 -----------------------------
                                                 Michael Zak, General Partner


                                          ONE LIBERTY FUND III, L.P.

                                          By:  OneLiberty Partners III, L.P.,
                                               its general partner


                                          By:    /s/ Edwin M. Kania, Jr.
                                                 -----------------------------
                                          Name:  Edwin M. Kania, Jr.
                                          Title: General Partner


<PAGE>   31
                                          NEW ENTERPRISE ASSOCIATES VII, LP


                                          By:    /s/ Arthur Marks
                                                 -----------------------------
                                          Name:  Arthur Marks
                                          Title: General Partner

                                          NEA PRESIDENTS' FUND, L.P.


                                          By:    /s/ Arthur Marks
                                                 -----------------------------
                                          Name:  Arthur Marks
                                          Title: General Partner


                                          FW VENTURES IV, L.P.

                                                 By:    /s/ David G. Brown
                                                        ------------------------
                                                 Name:  David G. Brown
                                                 Title: Vice President



                                          PRISM VENTURE PARTNERS I, L.P.

                                          By:    Prism Investment Partners,
                                                 L.P., its general partner

                                                 By:   Prism Venture Partners,
                                                       L.L.C., its general
                                                       partner


                                                 By:   /s/ Robert Fleming
                                                       -------------------------
                                                       Managing Director



<PAGE>   32
                               AMENDMENT NO. 2 TO

                              SITARA NETWORKS, INC.
                           SIXTH AMENDED AND RESTATED
                          REGISTRATION RIGHTS AGREEMENT

                               NOVEMBER 16, 2000

     WHEREAS, the undersigned, being (i) Sitara Networks, Inc., a Delaware
corporation (the "Company"), (ii) the holders (the "Required Holders") of at
least sixty (60%) percent of the issued and outstanding shares of Series A
Convertible Preferred Stock, $0.00001 par value per share, (the "Series A
Stock"), Series B Convertible Preferred Stock, $0.00001 par value per share (the
"Series B Stock"), Series C Convertible Preferred Stock, $0.00001 par value per
share (the "Series C Stock"), Series D Convertible Preferred Stock, $0.00001 par
value (the "Series D Stock"), Series E Convertible Preferred Stock, $0.00001 par
value per share (the "Series E Stock"), Series F Convertible Preferred Stock,
$0.00001 par value per share (the "Series F Stock"), and Series G Convertible
Preferred tock, $0.00001 (the "Series G Stock" and together with the Series A
Stock, the Series B Stock, the Series C Stock, the Series D Stock, the Series E
Stock, and the Series F Stock the "Preferred Stock") of the Company, calculated
as a single class (treating all Preferred Stock for all purposes herein as if
converted to Common Stock, par value $.00001 per share ), and (iii) Malik Z.
Khan, in his capacity as the founder of the Company (the "Founder"), desire to
amend that certain Sixth Amended and Restated Registration Rights Agreement,
dated as of June 16, 2000 by and among the Company and the other parties thereto
(the "Registration Rights Agreement");

     WHEREAS, Section 13 of the Registration Rights Agreement permits amendments
to such agreement upon the written consent of the Company, the Required Holders
and the Founder; and

     WHEREAS, the capitalized terms not defined herein shall have the meanings
ascribed to them in the Registration Rights Agreement;

     NOW, THEREFORE, in consideration of the mutual covenants set forth herein,
the parties hereto agree as follows:

     That the Registration Rights Agreement be amended to the extent necessary
to irrevocably waive (i) the right of each Holder to have any shares of
Registrable Securities or Founder Registrable Securities included on any
Registration Statement filed with respect to the Company's Initial Public
Offering (provided that the Company's Initial Public Offering is consummated on
or prior to June 30, 2001) and (ii) the right to receive notice of the filing of
any such Registration Statement.


                            [SIGNATURE PAGES FOLLOW]


<PAGE>   33



      IN WITNESS WHEREOF, the undersigned have executed this Amendment No. 2 to
the Sitara Networks, Inc. Sixth Amended and Restated Registration Rights
Agreement as of the date first written above.

                               COMPANY:

                               SITARA NETWORKS, INC.


                               By:   /s/ Malik Khan
                                     ------------------------
                               Name: Malik Khan
                               Title:President


                               FOUNDER:


                               Malik Z. Khan


                               PREFERRED STOCKHOLDERS:

                               CHARLES RIVER PARTNERSHIP VII, L.P.


                               By:   /s/ Michael J. Zak
                                     ---------------------------
                               Name: Michael J. Zak
                               Title:

                               ONE LIBERTY FUND III, L.P.

                               By:  OneLiberty Partners III, L.P.,
                                    its general partner


                               By:   /s/ Edwin M. Kania, Jr.
                                     ---------------------------
                               Name: Edwin M. Kania, Jr.
                               Title: General Partner


<PAGE>   34


                               NEW ENTERPRISE ASSOCIATES VII, LP


                               By:   /s/ Arthur Marks
                                     --------------------------
                               Name: Arthur Marks
                               Title: General Partner

                               NEA PRESIDENTS' FUND, L.P.


                               By:   /s/ Arthur Marks
                                     --------------------------
                               Name: Arthur Marks
                               Title: General Partner


                               FW VENTURES IV, L.P.


                               By:   /s/ John H. Fant
                                     --------------------------
                               Name: John H. Fant
                               Title: Vice President



                               PRISM VENTURE PARTNERS I, L.P.

                               By:   Prism Investment Partners, L.P., its
                                     general partner

                                     By:   Prism Venture Partners, L.L.C., its
                                           general partner


                                     By:   /s/ Robert Fleming
                                           -----------------------------------
                                           Managing Director