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EXHIBIT 4.2.1

NUMBER A-[NUMBER]           OCCAM NETWORKS, INC.               *[SHARES]* SHARES
                           A DELAWARE CORPORATION           SERIES A CONVERTIBLE
                                                                 Preferred Stock

THIS CERTIFIES THAT [Stockholder] is the record holder of [SpelledOut]
([Shares]) fully paid and nonassessable shares of the Series A Convertible
Preferred Stock of Occam Networks, Inc., transferable only on the share register
of the corporation, in person or by duly authorized attorney, upon surrender of
this certificate properly endorsed or assigned.

This certificate and the shares represented hereby are issued and shall be held
subject to all the provisions of the Certificate of Incorporation, any
applicable Certificate of Designation, the Bylaws of the corporation and any
amendments thereto, to all of which the holder of this certificate, by
acceptance hereof, assents.

A statement of the number of shares constituting each class and/or series of
shares of stock of the corporation and the designation thereof, and a statement
of the rights, preferences, privileges, and restrictions granted to or imposed
upon such shares and the holders thereof, may be obtained by any stockholder at
the principal office of the corporation, upon request and without charge.

WITNESS the signatures of the corporation's duly authorized officers, dated
---------------------.


----------------------------------            ----------------------------------
Lee N. Hilbert, Vice President                       Howard M. Bailey, Secretary

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FOR VALUE RECEIVED, __________________ HEREBY SELL, ASSIGN, AND TRANSFER UNTO
____________________________________ SHARES OF CAPITAL STOCK REPRESENTED BY THE
WITHIN CERTIFICATE, AND DO HEREBY IRREVOCABLY CONSTITUTE AND APPOINT ___________
ATTORNEY TO TRANSFER SUCH STOCK ON THE SHARE REGISTER OF THE WITHIN-NAMED
CORPORATION WITH FULL POWER OF SUBSTITUTION IN THE PREMISES.

DATED _________________, ____

IN PRESENCE OF
               ------------------------------     ------------------------------
                          (Witness) (Stockholder)

                                                  ------------------------------
                                                                   (Stockholder)

NOTICE: THE SIGNATURE ON THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS
WRITTEN UPON THE FACE OF THIS CERTIFICATE, IN EVERY PARTICULAR, WITHOUT
ALTERATION OR ENLARGEMENT, OR ANY CHANGE WHATSOEVER.

THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES
ACT OF 1933 (THE "ACT") AND MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED,
PLEDGED OR HYPOTHECATED UNLESS AND UNTIL REGISTERED UNDER THE ACT OR, IN THE
OPINION OF COUNSEL SATISFACTORY TO THE ISSUER OF THESE SECURITIES, SUCH OFFER,
SALE OR TRANSFER, PLEDGE OR HYPOTHECATION OTHERWISE COMPLIES WITH THE ACT.

COPIES OF THE AGREEMENT COVERING THE PURCHASE OF THESE SHARES AND RESTRICTING
THEIR VOTING AND TRANSFER MAY BE OBTAINED AT NO COST BY WRITTEN REQUEST MADE BY
THE HOLDER OF RECORD OF THIS CERTIFICATE TO THE SECRETARY OF THE COMPANY AT THE
PRINCIPAL EXECUTIVE OFFICE OF THE COMPANY.