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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                  ------------

                                  SCHEDULE 13G

           INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO
              RULES 13d-1 (b), (c) AND (d) AND AMENDMENTS THERETO
                           FILED PURSUANT TO 13d-2 (b)

                       Cogent Communications Group, Inc.
--------------------------------------------------------------------------------
                                (Name of Issuer)

                                  Common Stock
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    19239V104
--------------------------------------------------------------------------------
                                 (CUSIP Number)

                                December 31, 2002
--------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)

Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

      |_|   Rule 13d-1(b)

      |_|   Rule 13d-1(c)

      |X|   Rule 13d-1(d)

                                 Page 1 of 22 pages
                      Exhibit Index Contained on Page 21.



CUSIP No.  19239V104                                          Page 2 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Worldview Technology Partners IV, L.P. ("WVTP IV")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Delaware
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        548,531 shares,  except that Worldview  Capital IV, L.P.
                        ("WVC IV"), the general partner of Worldview  Technology
                        Partners  IV,  L.P.  ("WVTP  IV"),  Worldview  Equity I,
                        L.L.C.  ("WVE I"),  the  general  partner of WVC IV, and
                        James Wei ("Wei"),  Michael  Orsak  ("Orsak") and Susumu
                        Tanaka  ("Tanaka"),  the members of WVE I, may be deemed
                        to have shared power to vote these shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              See response to row 5.
    EACH                --------------------------------------------------------
  REPORTING       7     SOLE DISPOSITIVE POWER
   PERSON
    WITH                548,531 shares,  except that WVC IV, the general partner
                        of WVTP IV,  WVE I, the  general  partner of WVC IV, and
                        Wei,  Orsak and  Tanaka,  the  members  of WVE I, may be
                        deemed to have shared power to dispose of these shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        See response to row 7.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      548,531 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      4.04%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                          Page 3 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Worldview Technology International IV, L.P. ("WVTI IV")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Delaware
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        89,115 shares,  except that WVC IV, the general  partner
                        of WVTI IV,  WVE I, the  general  partner of WVC IV, and
                        Wei,  Orsak and  Tanaka,  the  members  of WVE I, may be
                        deemed to have shared power to vote these shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              See response to row 5.
    EACH                --------------------------------------------------------
  REPORTING       7     SOLE DISPOSITIVE POWER
   PERSON
    WITH                89,115 shares,  except that WVC IV, the general  partner
                        of WVTI IV,  WVE I, the  general  partner of WVC IV, and
                        Wei,  Orsak and  Tanaka,  the  members  of WVE I, may be
                        deemed to have shared power to dispose of these shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        See response to row 7.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      89,115 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      Less than 1%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                          Page 4 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Worldview Strategic Partners IV, L.P. ("WVSP IV")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Delaware
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        4,048 shares, except that WVC IV, the general partner of
                        WVSP IV, WVE I, the general  partner of WVC IV, and Wei,
                        Orsak and Tanaka, the members of WVE I, may be deemed to
                        have shared voting power to vote these shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              See response to row 5.
    EACH                --------------------------------------------------------
  REPORTING       7     SOLE DISPOSITIVE POWER
   PERSON
    WITH                4,048 shares, except that WVC IV, the general partner of
                        WVSP IV, WVE I, the general  partner of WVC IV, and Wei,
                        Orsak and Tanaka, the members of WVE I, may be deemed to
                        have shared power to dispose of these shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        See response to row 7.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      4,048 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      Less than 1%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                          Page 5 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Worldview Capital IV, L.P. ("WVC IV")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Delaware
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        641,694  shares,  of which 548,531 are directly owned by
                        WVTP IV; 89,115 are directly owned by WVTI IV; and 4,048
                        are  directly  owned by WVSP  IV.  WVC IV,  the  general
                        partner  of WVTP IV,  WVTI IV and  WVSP  IV,  WVE I, the
                        general  partner of WVC IV, and Wei,  Orsak and  Tanaka,
                        the members of WVE I, may be deemed to have shared power
                        to vote these shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              See response to row 5.
    EACH                --------------------------------------------------------
  REPORTING       7     SOLE DISPOSITIVE POWER
   PERSON
    WITH                641,694  shares,  of which 548,531 are directly owned by
                        WVTP IV; 89,115 are directly owned by WVTI IV; and 4,048
                        are  directly  owned by WVSP  IV.  WVC IV,  the  general
                        partner  of WVTP IV,  WVTI IV and  WVSP  IV,  WVE I, the
                        general  partner of WVC IV, and Wei,  Orsak and  Tanaka,
                        the members of WVE I, may be deemed to have shared power
                        to dispose of these shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        See response to row 7.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      641,694 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      4.73%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                          Page 6 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Worldview Technology Partners III, L.P. ("WVTP III")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Delaware
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        1,294,289  shares,  except that  Worldview  Capital III,
                        L.P. ("WVC III"),  the general  partner of WVTP III, WVE
                        I, the general  partner of WVC III,  and Wei,  Orsak and
                        Tanaka,  the  members  of WVE I, may be  deemed  to have
                        shared power to vote these shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              See response to row 5.
    EACH                --------------------------------------------------------
  REPORTING       7     SOLE DISPOSITIVE POWER
   PERSON
    WITH                1,294,289  shares,  except  that  WVC III,  the  general
                        partner of WVTP III,  WVE I, the general  partner of WVC
                        III,  and Wei,  Orsak and Tanaka,  the members of WVE I,
                        may be deemed to have  shared  power to dispose of these
                        shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        See response to row 7.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      1,294,289 shares
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      9.53%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                          Page 7 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Worldview Technology International III, L.P. ("WVTI III")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Delaware
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        319,032 shares, except that WVC III, the general partner
                        of WVTI III, WVE I, the general  partner of WVC III, and
                        Wei,  Orsak and  Tanaka,  the  members  of WVE I, may be
                        deemed to have shared power to vote these shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              See response to row 5.
    EACH                --------------------------------------------------------
  REPORTING       7     SOLE DISPOSITIVE POWER
   PERSON
    WITH                319,032 shares, except that WVC III, the general partner
                        of WVTI III, WVE I, the general  partner of WVC III, and
                        Wei,  Orsak and  Tanaka,  the  members  of WVE I, may be
                        deemed to have shared power to dispose of these shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        See response to row 7.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      319,032 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      2.35%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                          Page 8 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Worldview Strategic Partners III, L.P. ("WVSP III")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Delaware
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        28,679 shares,  except that WVC III, the general partner
                        of WVSP III, WVE I, the general  partner of WVC III, and
                        Wei,  Orsak and  Tanaka,  the  members  of WVE I, may be
                        deemed to have shared voting power to vote these shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              See response to row 5.
    EACH                --------------------------------------------------------
  REPORTING       7     SOLE DISPOSITIVE POWER
   PERSON
    WITH                28,679 shares,  except that WVC III, the general partner
                        of WVSP III, WVE I, the general  partner of WVC III, and
                        Wei,  Orsak and  Tanaka,  the  members  of WVE I, may be
                        deemed to have shared power to dispose of these shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        See response to row 7.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      28,679 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      Less than 1%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                          Page 9 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Worldview III Carrier Fund, L.P. ("WVCF III")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Delaware
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        31,724 shares,  except that WVC III, the general partner
                        of WVCF III, WVE I, the general  partner of WVC III, and
                        Wei,  Orsak and  Tanaka,  the  members  of WVE I, may be
                        deemed to have shared voting power to vote these shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              See response to row 5.
    EACH                --------------------------------------------------------
  REPORTING       7     SOLE DISPOSITIVE POWER
   PERSON
    WITH                31,724 shares,  except that WVC III, the general partner
                        of WVCF III, WVE I, the general  partner of WVC III, and
                        Wei,  Orsak and  Tanaka,  the  members  of WVE I, may be
                        deemed to have shared power to dispose of these shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        See response to row 7.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      31,724 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      Less than 1%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                         Page 10 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Worldview Capital III, L.P. ("WVC III")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Delaware
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        1,673,724  shares, of which 1,294,289 are directly owned
                        by WVTP III;  319,032  are  directly  owned by WVTI III;
                        28,679 are  directly  owned by WVSP III;  and 31,724 are
                        directly owned by WVCF III. WVC III, the general partner
                        of WVTP III, WVTI III, WVSP II, and WVCF III, WVE I, the
                        general  partner of WVC III, and Wei,  Orsak and Tanaka,
                        the members of WVE I, may be deemed to have shared power
                        to vote these shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              See response to row 5.
    EACH                --------------------------------------------------------
  REPORTING       7     SOLE DISPOSITIVE POWER
   PERSON
    WITH                1,673,724  shares, of which 1,294,289 are directly owned
                        by WVTP III;  319,032  are  directly  owned by WVTI III;
                        28,679 are  directly  owned by WVSP III;  and 31,724 are
                        directly owned by WVCF III. WVC III, the general partner
                        of WVTP III, WVTI III, WVSP II, and WVCF III, WVE I, the
                        general  partner of WVC III, and Wei,  Orsak and Tanaka,
                        the members of WVE I, may be deemed to have shared power
                        to dispose of these shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        See response to row 7.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      1,673,724 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      12.33%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                         Page 11 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Worldview Equity I, L.L.C. ("WVE I")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Delaware
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        2,315,418 shares, of which 548,531 are directly owned by
                        WVTP IV; 89,115 are directly owned by WVTI IV; 4,048 are
                        directly owned by WVSP IV;  1,294,289 are directly owned
                        by WVTP III;  319,032  are  directly  owned by WVTI III;
                        28,679 are  directly  owned by WVSP III;  and 31,724 are
                        directly  owned by WVCF III. WVE I, the general  partner
                        of WVC IV and WVC III, the respective  general  partners
                        of WVTP IV, WVTI IV and WVSP IV, and WVTP III, WVTI III,
                        WVSP III and WVCF III,  and Wei,  Orsak and Tanaka,  the
                        members of WVE I, may be deemed to have shared  power to
                        vote these shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              See response to row 5.
    EACH                --------------------------------------------------------
  REPORTING       7     SOLE DISPOSITIVE POWER
   PERSON
    WITH                2,315,418 shares, of which 548,531 are directly owned by
                        WVTP IV; 89,115 are directly owned by WVTI IV; 4,048 are
                        directly owned by WVSP IV;  1,294,289 are directly owned
                        by WVTP III;  319,032  are  directly  owned by WVTI III;
                        28,679 are  directly  owned by WVSP III;  and 31,724 are
                        directly  owned by WVCF III. WVE I, the general  partner
                        of WVC IV and WVC III, the respective  general  partners
                        of WVTP IV, WVTI IV and WVSP IV, and WVTP III, WVTI III,
                        WVSP III and WVCF III,  and Wei,  Orsak and Tanaka,  the
                        members of WVE I, may be deemed to have shared  power to
                        dispose of these shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        See response to row 7.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      2,315,418 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      17.06%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      00
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                         Page 12 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      James Wei ("Wei")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Canadian Citizen
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        0 shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              2,315,418 shares, of which 548,531 are directly owned by
    EACH                WVTP IV; 89,115 are directly owned by WVTI IV; 4,048 are
  REPORTING             directly owned by WVSP IV;  1,294,289 are directly owned
   PERSON               by WVTP III;  319,032  are  directly  owned by WVTI III;
    WITH                28,679 are  directly  owned by WVSP III;  and 31,724 are
                        directly  owned  by  WVCF  III.  WVC IV is  the  general
                        partner of WVTP IV,  WVTI IV and WVSP IV; WVC III is the
                        general partner of WVTP III, WVTI III, WVSP III and WVCF
                        II; WVE I is the general  partner of WVC IV and WVC III;
                        and Wei, a member of WVE I may be deemed to have  shared
                        power to vote these shares.
                        --------------------------------------------------------
                  7     SOLE DISPOSITIVE POWER

                        O shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        2,315,418 shares, of which 548,531 are directly owned by
                        WVTP IV; 89,115 are directly owned by WVTI IV; 4,048 are
                        directly owned by WVSP IV;  1,294,289 are directly owned
                        by WVTP III;  319,032  are  directly  owned by WVTI III;
                        28,679 are  directly  owned by WVSP III;  and 31,724 are
                        directly  owned  by  WVCF  III.  WVC IV is  the  general
                        partner of WVTP IV,  WVTI IV and WVSP IV; WVC III is the
                        general partner of WVTP III, WVTI III, WVSP III and WVCF
                        II; WVE I is the general  partner of WVC IV and WVC III;
                        and Wei, a member of WVE I may be deemed to have  shared
                        power to dispose of these shares.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      2,315,418 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      17.06%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

        IN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                         Page 13 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Michael Orsak ("Orsak")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      U.S. Citizen
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        0 shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              2,315,418 shares, of which 548,531 are directly owned by
    EACH                WVTP IV; 89,115 are directly owned by WVTI IV; 4,048 are
  REPORTING             directly owned by WVSP IV;  1,294,289 are directly owned
   PERSON               by WVTP III;  319,032  are  directly  owned by WVTI III;
    WITH                28,679 are  directly  owned by WVSP III;  and 31,724 are
                        directly  owned  by  WVCF  III.  WVC IV is  the  general
                        partner of WVTP IV,  WVTI IV and WVSP IV; WVC III is the
                        general partner of WVTP III, WVTI III, WVSP III and WVCF
                        II; WVE I is the general  partner of WVC IV and WVC III;
                        and  Orsak,  a  member  of WVE I may be  deemed  to have
                        shared power to vote these shares.
                        --------------------------------------------------------
                  7     SOLE DISPOSITIVE POWER

                        0 shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        2,315,418 shares, of which 548,531 are directly owned by
                        WVTP IV; 89,115 are directly owned by WVTI IV; 4,048 are
                        directly owned by WVSP IV;  1,294,289 are directly owned
                        by WVTP III;  319,032  are  directly  owned by WVTI III;
                        28,679 are  directly  owned by WVSP III;  and 31,724 are
                        directly  owned  by  WVCF  III.  WVC IV is  the  general
                        partner of WVTP IV,  WVTI IV and WVSP IV; WVC III is the
                        general partner of WVTP III, WVTI III, WVSP III and WVCF
                        II; WVE I is the general  partner of WVC IV and WVC III;
                        and  Orsak,  a  member  of WVE I may be  deemed  to have
                        shared power to dispose of these shares.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      2,315,418 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      17.06%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      IN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                         Page 14 of 22 Pages
--------------------------------------------------------------------------------
1     NAMES OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

      Susumu Tanaka ("Tanaka")
--------------------------------------------------------------------------------
2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                        (a)  |_|
                                                                        (b)  |X|
--------------------------------------------------------------------------------
3     SEC USE ONLY

--------------------------------------------------------------------------------
4     CITIZENSHIP OR PLACE OF ORGANIZATION

      Japanese Citizen
--------------------------------------------------------------------------------
                  5     SOLE VOTING POWER

                        0 shares.
  NUMBER OF             --------------------------------------------------------
   SHARES         6     SHARED VOTING POWER
BENEFICIALLY
  OWNED BY              2,315,418 shares, of which 548,531 are directly owned by
    EACH                WVTP IV; 89,115 are directly owned by WVTI IV; 4,048 are
  REPORTING             directly owned by WVSP IV;  1,294,289 are directly owned
   PERSON               by WVTP III;  319,032  are  directly  owned by WVTI III;
    WITH                28,679 are  directly  owned by WVSP III;  and 31,724 are
                        directly  owned  by  WVCF  III.  WVC IV is  the  general
                        partner of WVTP IV,  WVTI IV and WVSP IV; WVC III is the
                        general partner of WVTP III, WVTI III, WVSP III and WVCF
                        II; WVE I is the general  partner of WVC IV and WVC III;
                        and  Tanaka,  a member  of WVE I may be  deemed  to have
                        shared power to vote these shares.
                        --------------------------------------------------------
                  7     SOLE DISPOSITIVE POWER

                        0 shares.
                        --------------------------------------------------------
                  8     SHARED DISPOSITIVE POWER

                        2,315,418 shares, of which 548,531 are directly owned by
                        WVTP IV; 89,115 are directly owned by WVTI IV; 4,048 are
                        directly owned by WVSP IV;  1,294,289 are directly owned
                        by WVTP III;  319,032  are  directly  owned by WVTI III;
                        28,679 are  directly  owned by WVSP III;  and 31,724 are
                        directly  owned  by  WVCF  III.  WVC IV is  the  general
                        partner of WVTP IV,  WVTI IV and WVSP IV; WVC III is the
                        general partner of WVTP III, WVTI III, WVSP III and WVCF
                        II; WVE I is the general  partner of WVC IV and WVC III;
                        and  Tanaka,  a member  of WVE I may be  deemed  to have
                        shared power to dispose of these shares.
--------------------------------------------------------------------------------
9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      2,315,418 shares.
--------------------------------------------------------------------------------
10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

      |_|
--------------------------------------------------------------------------------
11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      17.06%
--------------------------------------------------------------------------------
12    TYPE OF REPORTING PERSON*

      IN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!



CUSIP No.  19239V104                                         Page 15 of 22 Pages
--------------------------------------------------------------------------------

ITEM 1(a).    NAME OF ISSUER: Cogent Communications Group, Inc.

ITEM 1(b).    ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:

              1015 31st Street N.W., Suite 330
              Washington, DC 20007

ITEM 2(a).    NAME OF PERSON FILING:

              This statement is filed by Worldview Technology Partners IV, L.P.,
              a Delaware limited partnership ("WVTP IV"),  Worldview  Technology
              International  IV, L.P.,  a Delaware  limited  partnership  ("WVTI
              IV"),  Worldview  Strategic  Partners IV, L.P., a Delaware limited
              partnership  ("WVSP IV"),  Worldview  Capital IV, L.P., a Delaware
              limited  partnership  ("WVC IV"),  Worldview  Equity I, L.L.C.,  a
              Delaware limited liability company ("WVE I"), Worldview Technology
              Partners III, L.P., a Delaware limited  partnership  ("WVTP III"),
              Worldview  Technology  International III, L.P., a Delaware limited
              partnership ("WVTI III"),  Worldview Strategic Partners III, L.P.,
              a Delaware limited partnership ("WVSP III"), Worldview III Carrier
              Fund, L.P., a Delaware limited partnership ("WVCF III"), Worldview
              Capital III,  L.P.,  a Delaware  limited  partnership  ("WVC II"),
              James Wei  ("Wei"),  Michael  Orsak  ("Orsak")  and Susumu  Tanaka
              ("Tanaka").   The   foregoing   entities   and   individuals   are
              collectively referred to as the "Reporting Persons."

              WVC IV is the general partner of WVTP IV, WVTI IV and WVSP IV. WVE
              I is the general partner of WVC IV. WVC IV and WVE I may be deemed
              to have shared power to vote and shared power to dispose of shares
              of the issuer directly owned by WVTP IV, WVTI IV and WVSP IV. Wei,
              Orsak and  Tanaka  are the  managing  members of WVE I, and may be
              deemed to have shared power to vote and shared power to dispose of
              the shares of issuer  directly  owned by WVTP IV, WVTI IV and WVSP
              IV.

              WVC III is the general partner of WVTP III, WVTI III, WVSP III and
              WVCF III. WVE I is the general partner of WVC III. WVC III and WVE
              I may be deemed to have shared  power to vote and shared  power to
              dispose of shares of the issuer  directly  owned by WVTP III, WVTI
              III, WVSP III and WVCF III. Wei, Orsak and Tanaka are the managing
              members of WVE I, and may be deemed to have  shared  power to vote
              and shared power to dispose of the shares of issuer directly owned
              by WVTP III, WVTI III, WVSP III and WVCF III.

ITEM 2(b).    ADDRESS OF PRINCIPAL BUSINESS OFFICE, OR, IF NONE, RESIDENCE:

              The  address  of the  principal  business  office  for each of the
              Reporting Persons is:

              435 Tasso Street, Suite 120
              Palo Alto, California 94301


CUSIP No.  19239V104                                         Page 16 of 22 Pages
--------------------------------------------------------------------------------

ITEM 2(c)     CITIZENSHIP:

              WVC IV, WVTP IV, WVTI  IV,WVSP  IV, WVC III,  WVTP III,  WVTI III,
              WVSP III and WVCF III are Delaware limited partnerships.  WVE I is
              a Delaware limited liability  company.  Wei is a Canadian citizen.
              Orsak is a United States citizen. Tanaka is a Japanese citizen.

ITEM 2(d).    TITLE OF CLASS OF SECURITIES:

              Common Stock.

ITEM 2(e).    CUSIP NUMBER: 19239V104

ITEM 3.       Not Applicable.

ITEM 4.       OWNERSHIP:

              The approximate  percentages of shares of Common Stock reported as
              beneficially   owned  by  the  Reporting  Persons  is  based  upon
              3,483,898  shares of Common  Stock  outstanding  as of November 8,
              2002,  as reported in the Issuer's  Quarterly  Report on Form 10-Q
              for the fiscal  quarter ended  September 30, 2002,  plus 2,600,000
              shares of Common Stock  issuable  upon  conversion of the Issuer's
              issued and  outstanding  Series A Preferred  Stock (the  "Series A
              Preferred"),  2,514,046  shares  of  Common  Stock  issuable  upon
              conversion  of  the  Issuer's  issued  and  outstanding  Series  B
              Preferred Stock (the "Series B Preferred"),  and 4,977,340  shares
              of Common Stock  issuable upon  conversion of the Issuer's  issued
              and   outstanding   Series  C  Preferred   Stock  (the  "Series  C
              Preferred"),  all as reported in the Issuer's  Quarterly Report on
              Form 10-Q for the fiscal quarter ended September 30, 2002. For all
              computations  with respect to this  Schedule  13G, the  percentage
              beneficially  owned by each  reporting  person was calculated on a
              fully diluted,  as converted  basis of all of the Issuer's  issued
              and outstanding Series A Preferred,  Series B Preferred and Series
              C Preferred, including shares held by third parties.

              Amounts  shown as  beneficially  owned by each of WVTP IV, WVC IV,
              WVE I, Wei,  Orsak and Tanaka include the 548,531 shares of Common
              Stock into which the shares of Series C Preferred  held by WVTP IV
              may be converted.

              Amounts  shown as  beneficially  owned by each of WVTI IV, WVC IV,
              WVE I, Wei,  Orsak and Tanaka  include the 89,115 shares of Common
              Stock into which the shares of Series C Preferred  held by WVTP IV
              may be converted.

              Amounts  shown as  beneficially  owned by each of WVSP IV, WVC IV,
              WVE I, Wei,  Orsak and Tanaka  include the 4,048  shares of Common
              Stock into which the shares of Series C Preferred  held by WVTP IV
              may be converted.

              Amounts shown as beneficially  owned by each of WVTP III, WVC III,
              WVE I, Wei,  Orsak and Tanaka include (i) 729,094 shares of Common
              Stock into which the shares of Series A Preferred held by WVTP III
              may be converted,  (ii) 322,994  shares of Common Stock into which
              the  shares  of  Series  B  Preferred  held  by  WVTP  III  may be
              converted, and (iii) 242,200 shares of Common Stock into which the
              shares of Series C Preferred held by WVTP III may be converted.

              Amounts shown as beneficially  owned by each of WVTI III, WVC III,



CUSIP No.  19239V104                                         Page 17 of 22 Pages
--------------------------------------------------------------------------------

              WVE I, Wei,  Orsak and Tanaka include (i) 179,749 shares of Common
              Stock into which the shares of Series A Preferred held by WVTI III
              may be  converted,  (ii) 79,597  shares of Common Stock into which
              the  shares  of  Series  B  Preferred  held  by  WVTI  III  may be
              converted,  and (iii) 59,686 shares of Common Stock into which the
              shares of Series C Preferred held by WVTI III may be converted.

              Amounts shown as beneficially  owned by each of WVSP III, WVC III,
              WVE I, Wei,  Orsak and Tanaka  include (i) 16,157 shares of Common
              Stock into which the shares of Series A Preferred held by WVSP III
              may be converted, (ii) 7,156 shares of Common Stock into which the
              shares of Series B  Preferred  held by WVSP III may be  converted,
              and (iii)  5,366  shares of Common  Stock into which the shares of
              Series C Preferred held by WVSP III may be converted.

              Amounts shown as beneficially  owned by each of WVCF III, WVC III,
              WVE I, Wei,  Orsak and Tanaka  include (i) 18,130 shares of Common
              Stock into which the shares of Series B Preferred held by WVCF III
              may be converted and (ii) 13,595 shares of Common Stock into which
              the  shares  of  Series  C  Preferred  held  by  WVCF  III  may be
              converted.

              The  following  information  with respect to the  ownership of the
              Common Stock of the issuer by the persons filing this Statement is
              provided as of December 31, 2002:

                 (a) Amount beneficially owned:

                     See Row 9 of cover page for each Reporting Person.

                 (b) Percent of Class:

                     See Row 11 of cover page for each Reporting Person.

                 (c) Number of shares as to which such person has:

                    (i) Sole power to vote or to direct the vote:

                        See Row 5 of cover page for each Reporting Person.

                   (ii) Shared power to vote or to direct the vote:

                        See Row 6 of cover page for each Reporting Person.



CUSIP No.  19239V104                                         Page 18 of 22 Pages
--------------------------------------------------------------------------------

                  (iii) Sole power to dispose or to direct the disposition of:

                        See Row 7 of cover page for each Reporting Person.

                   (iv) Shared power to dispose or to direct the disposition of:

                        See Row 8 of cover page for each Reporting Person.

ITEM 5.       OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS:

              Not applicable.

ITEM 6.       OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON:

              Under certain  circumstances set forth in the limited  partnership
              agreements  of WVC IV, WVTP IV,  WVTI IV,  WVSP IV, WVC III,  WVTP
              III,  WVTI  III,  WVSP III and WVCF II and the  limited  liability
              company  agreement of WVE I, the general and limited  partners and
              members of each of such  entities  may be deemed to have the right
              to receive  dividends  from,  or the  proceeds  from,  the sale of
              shares of the issuer owned by each such entity of which they are a
              partner or member.

ITEM 7.       IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED
              THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY:

              Not applicable.

ITEM 8.       IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP:

              By making this filing, the Reporting Persons acknowledge that they
              may be deemed  to  constitute  a "group"  within  the  meaning  of
              Section  13(d)(3)  of the  Securities  Exchange  Act of  1934,  as
              amended,  in  connection  with the  securities  of the  Issuer  (a
              "Section  13  Group").   In  addition,   the   Reporting   Persons
              acknowledge  that they could be deemed to  constitute a Section 13
              Group with each other party to that  certain  Amended and Restated
              Stockholders  Agreement of the Company, dated October 16, 2001, as
              incorporated  by reference  from Exhibit 4.1 to the Company's Form
              S-4/A filed with the Securities and Exchange Commission on January
              7, 2002.  Each  Reporting  Person  disclaims  the  existence  of a
              Section 13 Group and disclaims  beneficial ownership of all shares
              of Common Stock or securities  convertible into or exercisable for
              Common  Stock other than any shares or other  securities  reported
              herein as being owned by it, him or her, as the case may be.



CUSIP No.  19239V104                                         Page 19 of 22 Pages
--------------------------------------------------------------------------------

ITEM 9.       NOTICE OF DISSOLUTION OF GROUP:

              Not applicable.

ITEM 10.      CERTIFICATION:

              Not applicable.



CUSIP No.  19239V104                                         Page 20 of 22 Pages
--------------------------------------------------------------------------------

                                   SIGNATURES

              After  reasonable  inquiry  and to the  best of my  knowledge  and
belief,  I certify  that the  information  set forth in this  statement is true,
complete and correct.

Date: February 14, 2003

                                   JAMES WEI


                                   By: /s/ James Wei
                                       -----------------------------------------

                                   James  Wei,  individually,  and on  behalf of
                                   WVTP IV, in his  capacity  as a member of WVE
                                   I, the general partner of WVC IV, the general
                                   partner  of WVTP IV, on behalf of WVTI IV, in
                                   his  capacity  as a  member  of  WVE  I,  the
                                   general   partner  of  WVC  IV,  the  general
                                   partner  of WVTI IV, on behalf of WVSP IV, in
                                   his  capacity  as a  member  of  WVE  I,  the
                                   general   partner  of  WVC  IV,  the  general
                                   partner  of WVSP IV,  on behalf of WVC IV, in
                                   his  capacity  as a  member  of  WVE  I,  the
                                   general  partner  of WVC I, and on  behalf of
                                   WVE I in his capacity as a member thereof; on
                                   behalf  of WVTP  III,  in his  capacity  as a
                                   member of WVE I, the  general  partner of WVC
                                   III,  the  general  partner  of WVTP III,  on
                                   behalf  of WVTI  III,  in his  capacity  as a
                                   member of WVE I, the  general  partner of WVC
                                   III,  the  general  partner  of WVTI III,  on
                                   behalf  of WVSP  III,  in his  capacity  as a
                                   member of WVE I, the  general  partner of WVC
                                   III,  the  general  partner  of WVSP III,  on
                                   behalf  of WVCF  III,  in his  capacity  as a
                                   member of WVE I, the  general  partner of WVC
                                   III,  the  general  partner  of WVCF III,  on
                                   behalf  of  WVC  III,  in his  capacity  as a
                                   member of WVE I, the  general  partner of WVC
                                   III,  and on behalf of WVE I in his  capacity
                                   as a member thereof.

                                   MICHAEL ORSAK


                                   By: /s/ Michael Orsak
                                       -----------------------------------------
                                       Michael Orsak

                                   SUSUMU TANAKA


                                   By: /s/ Susumu Tanaka
                                       -----------------------------------------
                                       Susumu Tanaka


CUSIP No.  19239V104                                         Page 21 of 22 Pages
--------------------------------------------------------------------------------

                                  EXHIBIT INDEX

                                                            Found on
                                                          Sequentially
Exhibit                                                   Numbered Page
-------                                                   -------------

Exhibit A:  Agreement of Joint Filing                          22


CUSIP No.  19239V104                                         Page 22 of 22 Pages
--------------------------------------------------------------------------------

                                    EXHIBIT A

                            Agreement of Joint Filing

              The  undersigned  hereby agree that a single  Schedule 13G (or any
amendment thereto) relating to the Common Stock of Cogent  Communications Group,
Inc. shall be filed on behalf of each of the undersigned and that this Agreement
shall be filed as an exhibit to such Schedule 13G.

Date: February 14, 2003

                                   JAMES WEI


                                   By:  /s/ James Wei
                                       -----------------------------------------

                                   James  Wei,  individually,  and on  behalf of
                                   WVTP IV, in his  capacity  as a member of WVE
                                   I, the general partner of WVC IV, the general
                                   partner  of WVTP IV, on behalf of WVTI IV, in
                                   his  capacity  as a  member  of  WVE  I,  the
                                   general   partner  of  WVC  IV,  the  general
                                   partner  of WVTI IV, on behalf of WVSP IV, in
                                   his  capacity  as a  member  of  WVE  I,  the
                                   general   partner  of  WVC  IV,  the  general
                                   partner  of WVSP IV,  on behalf of WVC IV, in
                                   his  capacity  as a  member  of  WVE  I,  the
                                   general  partner  of WVC I, and on  behalf of
                                   WVE I in his capacity as a member thereof; on
                                   behalf  of WVTP  III,  in his  capacity  as a
                                   member of WVE I, the  general  partner of WVC
                                   III,  the  general  partner  of WVTP III,  on
                                   behalf  of WVTI  III,  in his  capacity  as a
                                   member of WVE I, the  general  partner of WVC
                                   III,  the  general  partner  of WVTI III,  on
                                   behalf  of WVSP  III,  in his  capacity  as a
                                   member of WVE I, the  general  partner of WVC
                                   III,  the  general  partner  of WVSP III,  on
                                   behalf  of WVCF  III,  in his  capacity  as a
                                   member of WVE I, the  general  partner of WVC
                                   III,  the  general  partner  of WVCF III,  on
                                   behalf  of  WVC  III,  in his  capacity  as a
                                   member of WVE I, the  general  partner of WVC
                                   III,  and on behalf of WVE I in his  capacity
                                   as a member thereof.

                                   MICHAEL ORSAK


                                   By: /s/ Michael Orsak
                                       -----------------------------------------
                                       Michael Orsak

                                   SUSUMU TANAKA


                                   By: /s/ Susumu Tanaka
                                       -----------------------------------------
                                       Susumu Tanaka