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                                                                   EHXIBIT 10.01

                                 FIRST AMENDMENT

This First Amendment to the Services Agreement No. 01-02-203 ("Amendment") made
by and between George Reyes and ONI Systems Corp. is entered into as of the 9th
day of April 2002 (the "Amendment Effective Date") by George Reyes
("Contractor") and ONI Systems Corp. ("ONI").

                                    RECITALS

A.      The parties have previously entered into the Services Agreement No.
        01-02-203 ("Agreement"), effective as of January 24, 2002.

B.      The parties desire to amend the Agreement in order to extend its Term as
        provided below.

Accordingly, the parties agree as follows:

        1.      The terms used in this Amendment shall have the same meanings as
                set out in the Agreement.

        2.      Section 1 of the Statement of Work is hereby deleted in its
                entirety and replaced with the following:

                Contractor shall, consistent with the terms of this Agreement,
                perform services for, and on behalf of ONI for the three (3)
                month period following the Effective Date ("Initial Term"),
                which shall be automatically renewed for successive one (1)
                month periods ("Renewal Period") unless either party provides
                thirty (30) days prior written notice of its intent not to renew
                (collectively, "Term").

        3.      Section 3 of the Statement of Work should be modified by the
                insertion of the following at the end of the provision:

                As consideration for Services rendered by Contractor during any
                Renewal Period following the Initial Term, ONI will pay
                Contractor twenty thousand dollars ($20,000) and grant
                Contractor a stock option to purchase eight thousand (8,000)
                shares of ONI's common stock with an exercise price equal to the
                fair market value on the date of grant. The stock option(s) must
                be approved by ONI's Board of Directors. The option(s) will vest
                and become exercisable upon the monthly anniversary of the
                Effective Date. Vesting will depend upon Contractor continuing
                to provide Services to ONI for each Renewal Period. Contractor
                will be able to exercise the option for a period of one (1) year
                following the date on which Contractor ceases to provide
                Services to ONI, provided that the option may not be exercised
                more than ten (10) years after the date of grant. The option
                will be subject to the terms of ONI's 2000 Equity Incentive Plan
                and a Stock Option Agreement between Contractor and ONI.

        4.      This Amendment shall prevail and control with respect to any
                inconsistency between the terms of this Amendment and the terms
                of the Agreement. Except as specifically provided by this
                Amendment, the Agreement shall continue in full force and effect
                in accordance with its terms. This Amendment shall be effective
                as of the Amendment Effective Date set forth above.

        In witness whereof, the parties have caused this Amendment to be
executed by their respective authorized representatives.


ONI SYSTEMS CORP.                       GEORGE REYES ("CONTRACTOR")



Signed Name: /s/ Stewart Grierson       Signed Name: /s/ George Reyes
            -------------------------               ----------------------------

Printed Name: Stewart Grierson
             ------------------------

Title: V.P. Corporate Controller
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Date: 4/17/02                           Date: 4/16/02
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