EXHIBIT 1

                                   EXHIBIT 1

                             JOINT FILING AGREEMENT

     This  Agreement is dated as of June 9, 2003 among Sierra  Ventures V, L.P.,
Sierra Ventures VI, L.P., SV Associates VI, L.P., Sierra Ventures VII, L.P., and
Sierra Ventures Associates VII LLC (collectively, the "Reporting Persons").

                                   WITNESSETH

     WHEREAS,  the  Reporting  Persons may be required to file a statement,  and
amendments thereto, containing the information required by Schedule 13D pursuant
to  Section  13(d) of the  Securities  Exchange  Act of 1934,  as  amended  (the
"Exchange Act"), and Rule 13d-1 promulgated  thereunder,  in connection with the
acquisition  of shares of  capital  stock of  Larscom  Incorporated,  a Delaware
corporation; and

     WHEREAS, pursuant to Paragraph (k) of Rule 13d-1, the undersigned desire to
satisfy any  Schedule 13D filing  obligation  under Rule 13d-1 by a single joint
filing.

     NOW, THEREFORE,  in consideration of the foregoing,  the undersigned hereto
agree as follows:

1. The  undersigned  agree  that any  Statement  on  Schedule  13D to which this
Agreement is attached, and any amendments to such Statement, are filed on behalf
of each one of them.

2. This Agreement may be executed in any number of counterparts  and all of such
counterparts  taken  together  shall be  deemed to  constitute  one and the same
instrument.

IN WITNESS  WHEREOF,  the  undersigned  have  caused this  Agreement  to be duly
executed and delivered on the date above indicated.

SIERRA VENTURES V, L.P.               SIERRA VENTURES VI, L.P.

   By: SV Associates V, L.P.             By: SV Associates VI, L.P.
       Its General Partner                   Its General Partner

       By: /s/ Xxxxxxx X. Xxxxxx             By: /s/ Xxxxxxx X. Xxxxxx
           ---------------------                 ---------------------
           Name:  Xxxxxxx X. Xxxxxx              Name:  Xxxxxxx X. Xxxxxx
             Title: General Partner              Title: General Partner


SV ASSOCIATES V, L.P.                 SV ASSOCIATES VI, L.P.


       By: /s/ Xxxxxxx X. Xxxxxx             By: /s/ Xxxxxxx X. Xxxxxx
           ---------------------                 ---------------------
           Name:  Xxxxxxx X. Xxxxxx              Name:  Xxxxxxx X. Xxxxxx
           Title: General Partner                Title: General Partner

SIERRA VENTURES ASSOCIATES VII LLC    SIERRA VENTURES VII, L.P.

                                         By: Sierra Ventures Associates VII LLC
       By: /s/ Xxxxxxx X. Xxxxxx          Its General Partner
           ---------------------
           Name:  Xxxxxxx X. Xxxxxx
             Title:  Managing Member
                                             By: /s/ Xxxxxxx X. Xxxxxx
                                                 Name:  Xxxxxxx X. Xxxxxx
                                                 Title:  Managing Member