<PAGE>   1
                                                                    EXHIBIT 10.1

                           ACCELERATED NETWORKS, INC.

                     FOUNDER/EMPLOYEE SHAREHOLDER AGREEMENT


               This Agreement is made this 28th day of March, 1997, by and
between Accelerated Networks, Inc., a California corporation (the "Company"),
and Suresh Nihalani ("Purchaser").

               NOW THEREFORE, IT IS HEREBY AGREED:

               1. Sale of Stock. Subject to the terms hereof, the Company shall
sell to Purchaser and Purchaser shall purchase from the Company, Seven Million,
Seven Hundred Fifty Thousand (7,750,000) shares of common stock of the Company
(the "Stock") at a price of $.001 per share ("Purchase Price").

               2. Payment of Purchase Price. Purchaser has previously paid the
Purchase Price by delivering to the Company a check for Seven Thousand Seven
Hundred Fifty ($7,750).

               3. Issuance of Shares. Upon receipt by the Company of the
Purchase Price, the Company shall issue a duly executed certificate evidencing
the Stock in the name of Purchaser.

               4. Representations and Warranties of Purchaser.

                      a. Investment Intent. This Agreement is made with
Purchaser in reliance upon his representation to the Company, which by
Purchaser's acceptance hereof Purchaser confirms, that the Stock has been
acquired with Purchaser's own funds for investment for an indefinite period for
Purchaser's own account, not as a nominee or agent, and not with a view to the
sale or distribution of any part thereof, and that Purchaser has no present
intention of selling, granting participation in, or otherwise distributing the
same. By executing this Agreement, Purchaser further represents that Purchaser
does not have any contract, undertaking, agreement or arrangement with any
person to sell, transfer, or grant participations, to such person or to any
third person, with respect to any of the Stock.

                      b. Restricted Securities. Purchaser understands that the
Stock has not been registered under the Securities Act of 1934, as amended (the
"Act"), on the ground that the sale provided for in this Agreement is exempt
from the registration requirements of the Act, and that the Company's reliance
on such exemption is predicated on his representations set forth herein.

               Purchaser understands that if the Company does not register with
the Securities and Exchange Commission pursuant to sections 12 or 15 of the
Securities Exchange Act of 1934, as amended, or if a registration statement
covering the Stock (or a filing pursuant to the exemption from registration
under Regulation A of the Act) under the Act is not in effect when


<PAGE>   2
Purchaser desires to sell the Stock, Purchaser may be required to hold the Stock
for an indeterminate period. Purchaser also acknowledges that Purchaser
understands that any sale of the Stock that might be made by Purchaser in
reliance upon Rule 144 under the Act may be made only in limited amounts in
accordance with the terms and conditions of that rule and that Purchaser may not
be able to sell the Stock at the time or in the amount Purchaser so desires.
Purchaser is familiar with Rule 144 and understands that the Stock constitutes
"restricted securities" within the meaning of that Rule.

                      c. Investment Experience. In connection with the
investment representations made herein Purchaser represents that he is able to
fend for himself in the transactions contemplated by this Agreement, has such
knowledge and experience in financial and business matters as to be capable of
evaluating the merits and risks of his investment, has the ability to bear the
economic risks of his investment and has been furnished with and has had access
to such information as he has requested and deems appropriate to his investment
decision.

                      d. Limitations on Disposition. Purchaser agrees that in no
event will Purchaser make a disposition of any of the Stock, unless and until
(a) Purchaser shall have notified the Company of the proposed disposition and
shall have furnished the Company with a statement of the circumstances
surrounding the proposed disposition, and (b) Purchaser shall have furnished the
Company with an opinion of counsel satisfactory to the Company to the effect
that (i) such disposition will not require registration of such Stock under the
Act, or (ii) that appropriate action necessary for compliance with the Act has
been taken, or (c) the Company shall have waived, expressly and in writing, its
rights under clauses (a) and (b) of this subparagraph. In addition, prior to any
disposition of any of the Stock, the Company may require the transferee or
assignee to provide in writing investment representations in a form acceptable
to the Company.

               The Company shall not be required (i) to transfer on its books
any shares of Stock of the Company which shall have been sold or transferred in
violation of any of the provisions set forth in this Agreement, or (ii) to treat
as owner of such shares or to accord the right to vote as such owner or to pay
dividends to any transferee to whom such shares shall have been so transferred.

                      e. Legends. All certificates representing any shares of
Stock of the Company subject to the provisions of this Agreement shall have
endorsed thereon the following legends:

                           (i) "THE SECURITIES REPRESENTED BY THIS CERTIFICATE
HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. THEY MAY
NOT BE OFFERED, SOLD, OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED IN THE
ABSENCE OF A REGISTRATION STATEMENT IN EFFECT WITH RESPECT TO SUCH SECURITIES,
OR DELIVERY OF AN OPINION OF COUNSEL SATISFACTORY TO THE ISSUER OF SUCH
SECURITIES THAT SUCH OFFER, SALE, TRANSFER, PLEDGE OR HYPOTHECATION IS IN FULL
COMPLIANCE WITH THE SECURITIES ACT OF 1933, AS AMENDED, OR


                                       2.


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UNLESS SOLD IN COMPLIANCE WITH RULE 144 UNDER SUCH ACT."

                           (ii) Any legend required to be placed thereon by
applicable state laws.

               5. Miscellaneous.

                      a. Further Instruments and Actions. The parties agree to
execute such further instruments and to take such further action as may
reasonably be necessary to carry out the intent of this Agreement.

                      b. Notices. Any notice required or permitted hereunder
shall be given in writing and shall be deemed effectively given upon personal
delivery or upon deposit in the United States Post Office, by registered or
certified mail with postage and fees prepaid, addressed to the other party
hereto at the address hereinafter shown below that party's signature or at such
other address as such party may designate by ten (10) days' advance written
notice to the other party hereto.

                      c. Governing Law, Assignment and Enforcement. This
Agreement is governed by the internal law of California and shall inure to the
benefit of the successors and assigns of the Company and, subject to the
restrictions on transfer herein set forth, be binding upon Purchaser, his heirs,
executors, administrators, guardians, successors and assigns. The prevailing
party in any action to enforce this Agreement shall be entitled to attorneys'
fees and costs. The parties agree that damages are not an adequate remedy for
Purchaser's breach hereof and the Company shall accordingly be entitled to
specific performance of this Agreement.

                      d. Amendments and Waivers. This Agreement represents the
entire understanding of the parties with respect to the subject matter hereof
and supersedes all previous understandings, written or oral. This Agreement may
only be amended with the written consent of the parties hereto and the Company's
assignees pursuant to subsection 4(c) hereof, or the successors or assigns of
the foregoing, and no oral waiver or amendment shall be effective under any
circumstances whatsoever.

                      e. Cooperation. Purchaser agrees to cooperate
affirmatively with the Company, to the extent reasonably requested by the
Company, to enforce rights and obligations pursuant to this Agreement.


                                       3.


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               6. California Commissioner of Corporations. THE SALE OF THE
SECURITIES WHICH ARE THE SUBJECT OF THIS AGREEMENT HAS NOT BEEN QUALIFIED WITH
THE COMMISSIONER OF CORPORATIONS OF THE STATE OF CALIFORNIA, AND THE ISSUANCE OF
SUCH SECURITIES OR THE PAYMENT OR RECEIPT OF ANY PART OF THE CONSIDERATION
THEREFOR PRIOR TO SUCH QUALIFICATION IS UNLAWFUL UNLESS THE SALE OF SECURITIES
IS EXEMPT FROM QUALIFICATION BY SECTION 25100, 25102 OR 25105 OF THE CALIFORNIA
CORPORATIONS CODE. THE RIGHTS OF ALL PARTIES TO THIS AGREEMENT ARE EXPRESSLY
CONDITIONED UNLESS THE SALE IS SO EXEMPT.

               IN WITNESS WHEREOF, the parties hereto have executed this
Agreement as of the day and year first above written.


                                       ACCELERATED NETWORKS, INC.


                                       By: /s/ Suresh Nihalani
                                       -------------------------------
                                              Suresh Nihalani
                                              President

                            Address:   5743 Corsa Avenue, Suite 221
                                       Westlake Village, CA 91362



                                       PURCHASER:


                                       /s/ Suresh Nihalani
                                       -------------------------------


                            Address:   c/o Accelerated Networks, Inc.
                                       5743 Corsa Avenue, Suite 221
                                       Westlake Village, CA 91362


                                       4.


<PAGE>   5
                           RESTATED FIRST AMENDMENT TO
                     FOUNDER/EMPLOYEE SHAREHOLDER AGREEMENT


        THIS RESTATED FIRST AMENDMENT TO FOUNDER/EMPLOYEE SHAREHOLDER AGREEMENT
dated as of May 30, 1997 (the "Amendment") amends that certain Founder/Employee
Shareholder Agreement ("Founder Agreement") by and between Accelerated Networks,
Inc., a California corporation (the "Company"), and Suresh Nihalani
("Purchaser"). This Amendment replaces that certain First Amendment to
Founder/Employee Shareholder Agreement dated as of April 14, 1997 by and between
the Company and Purchaser ("Previous Amendment"), which Previous Amendment shall
be of no further force or effect.

        NOW, THEREFORE, for good and valuable consideration, the receipt,
adequacy and sufficiency of which are hereby acknowledged, the parties hereto
covenant and agree as follows:

               1. Defined Terms. Capitalized terms not otherwise defined in this
Amendment shall have the respective meanings assigned to them in the Founder
Agreement.

               2. References to Founder Agreement. All references in the Founder
Agreement to "this Agreement", and to all other words referring to the Founder
Agreement (such as "herein", "hereto", "herewith" and "hereunder"), shall be
deemed to mean and refer to the Founder Agreement, as amended by this Amendment.

               3. Amendments to Founder Agreement.

                      (a) The definition of "Stock" in the Founder Agreement
shall be deemed to include all shares of Common Stock of the Company owned by
Purchaser on the date hereof.

                      (b) Subsection 5.b shall be deleted in its entirety and
replaced with the following:

                      b. Except as otherwise provided, all notices and other
        communications required or permitted hereunder shall be in writing,
        shall be effective when given, and shall in any event be deemed to be
        given upon receipt or, if earlier, (i) five (5) days after deposit with
        the U.S. postal service or other applicable postal service, if delivered
        by first class mail, postage prepaid, (ii) upon delivery, if delivered
        by hand, (iii) one (1) business day after the day of deposit with
        Federal Express or similar overnight courier, freight prepaid, if
        delivered by overnight courier or (iv) one (1) business day after the
        day of facsimile transmission, if delivered by facsimile transmission
        with copy by first class mail, postage prepaid, and shall be addressed,
        (a) if to Purchaser, at Purchaser's address set forth below its
        signature, or at such other address as Purchaser shall have furnished
        the Company in writing, or (b) if to the Company, at its address as set
        forth below, or at such other address as the Company shall have
        furnished to Purchaser in writing.


                                       5.


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                      (c) A new Section 7 and Section 8 shall be added to the
Founder Agreement as follows:

               7. Purchase Option. The Stock shall be subject to the following
       option ("Purchase Option"):

                      a. In the event Purchaser ceases to be continuously
        employed by the Company, or a parent or subsidiary of the Company, as a
        result of Purchaser's Voluntary Termination (as defined below) or
        Termination for Cause (as defined below), the Company may exercise the
        Purchase Option. The date when Purchaser's continuous employment ceases
        as a result of Voluntary Termination or Termination for Cause is
        hereinafter referred to as the "Termination Date."

                      b. Voluntary Termination shall include any voluntary
        cessation of employment with the Company unless such cessation of
        employment occurs within twelve (12) months of any of the following
        actions (unless such action is consummated with Purchaser's written
        approval): (i) a material decrease in the salary paid or benefits
        provided by the Company to Purchaser from the salary paid or benefits
        provided at the time of such decrease, other than a decrease consistent
        with an overall decline in the Company's financial condition or
        prospects and consistent with executive officer salary reductions
        generally, (ii) a material diminution in Purchaser's level of job
        responsibilities or position with the Company, or (iii) the relocation
        of Purchaser's place of employment to a location which is not within
        fifty (50) miles of the Company's current offices or Purchaser's current
        residence. Notwithstanding the foregoing, Voluntary Termination shall
        not include a cessation of employment arising from Purchaser's death or
        Purchaser's inability to perform his duties to the Company by reason of
        any medically determinable physical or mental impairment.

                      c. Termination for Cause shall include only the following:
        (i) theft of the Company's intellectual or other property other than
        unintentional takings of immaterial property, (ii) any other wilful and
        wrongful act not done in good faith by Purchaser causing material harm
        to the reputation of the Company, or (iii) conviction of a felony that
        adversely affects the Company.

                      d. The Company shall have the right at any time within
        sixty (60) days after the Termination Date to purchase the Stock from
        Purchaser at the price per share paid by Purchaser pursuant to this
        Agreement ("Option Price"). Stock subject to the Purchase Option may not
        be transferred by Purchaser (except for transfers by operation of law or
        other involuntary transfers and transfers by gift, will or intestate
        succession of Purchaser to Purchaser's spouse or lineal descendants or
        ancestors or a trust for the benefit of such persons if the transferee
        agrees in writing in a form satisfactory to the Company to be subject to
        the terms of the Founder Agreement). The Purchase Option shall
        terminate, and cease to be exercisable, with respect to any and all
        Stock in which Purchaser acquires a vested interest. For purposes of
        this Agreement, Purchaser shall acquire a


                                       6.


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        vested interest in 50% of the Stock immediately. Purchaser shall acquire
        a vested interest in the remaining 50% of the stock in equal monthly
        installments over the 48 months beginning on April 30, 1997, such that
        Purchaser shall have a fully vested interest in all of the Stock on
        April 29, 2001. Notwithstanding the foregoing, Purchaser shall not
        acquire a vested interest in any shares of Stock after the Termination
        Date. Notwithstanding the foregoing, Purchaser shall acquire a vested
        interest in all unvested stock upon consummation of a merger,
        consolidation, tender offer or other transaction or series of
        transactions in which securities possessing more than fifty percent
        (50%) of the total combined voting power of the Company's outstanding
        securities are transferred to a person or persons different from the
        persons holding those securities immediately prior to such transaction,
        or the sale, transfer or other disposition of all or substantially all
        of the Company's assets in complete liquidation or dissolution of the
        Company.

                      e. The Purchase Option, if exercised by the Company, shall
        be exercised by written notice signed by an officer of the Company and
        delivered or mailed as provided in subsection 5.b. The Company may pay
        for the shares of Stock it has elected to repurchase (i) by delivery of
        a check in the amount of the repurchase price for the Stock being
        repurchased, (ii) by cancellation by the Company of an amount of
        Purchaser's indebtedness to the Company or (iii) by a combination of (i)
        and (ii) so that the combined payment and cancellation of indebtedness
        equals such repurchase price.

                      f. Nothing in this Agreement shall affect in any manner
        whatsoever the at will status of Purchaser's employment or the right or
        power of the Company, or a parent or subsidiary of the Company, to
        terminate Purchaser's employment at any time, for any reason, with or
        without cause.

               8. Escrow of Shares.

                      a. Escrow Holder. The Stock issued under this Agreement
        shall be held in escrow by the Secretary of the Company, as escrow
        holder ("Escrow Holder"), along with an Assignment Separate from
        Certificate executed by Purchaser in blank, until expiration of the
        Company's Purchase Option described in Section 7 above.

                      b. Instructions to Escrow Holder. The Escrow Holder is
        hereby directed to permit transfer of the Stock only in accordance with
        this Agreement or instructions signed by both parties. In the event that
        further instructions are desired by the Escrow Holder, he or she shall
        be entitled to rely upon directions executed by a majority of the
        authorized number of the Company's Board of Directors. Notwithstanding
        anything else herein, the Escrow Holder (including persons and entities
        acting on behalf of or under authority of Escrow Holder), (i) shall have
        no liability for any act or omission hereunder unless it is shown that
        such act or omission was intentional and in bad faith, (ii) may act in
        accordance with any advice of counsel or any order, judgment or decree
        of any court, whether or not final, (iii) in the event of any dispute,
        the Escrow Holder may, in his or her sole discretion, take the course of
        action it deems appropriate or take no action whatsoever, and (iv) shall
        in no event be required to seek legal counsel but may do so at the
        Company's expense.


                                       7.


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                      c. Transfer to Transferee. If the Company exercises its
        Purchase Option hereunder, then the Escrow Holder, upon receipt of
        written notice of such option exercise from the proposed transferee,
        shall take all steps necessary to accomplish such transfer.

                      d. Transfer to Purchaser. When the Purchase Option has
        been exercised or expires unexercised or a portion of the Stock has been
        released from the Purchase Option, upon Purchaser's request the Escrow
        Holder shall promptly cause a new certificate to be issued for such
        released Stock and shall deliver such certificate to Purchaser.

                      e. Rights of Purchaser. Subject to the terms hereof,
        Purchaser shall have all the rights of a shareholder with respect to
        such Stock while such shares are held in escrow, including without
        limitation the right to vote the Stock and receive any cash dividends
        declared thereon.

                      f. Adjustment of Stock and Option Price. If, at any time
        or from time to time, there is (i) a dividend of any security, stock
        split or other change in the character or amount of any of the
        outstanding securities of the Company, or (ii) any consolidation, merger
        or sale of all, or substantially all, of the assets of the Company,
        then, in such event, any and all new, substituted or additional
        securities or other property to which Purchaser is entitled by reason of
        his ownership of the Stock shall be immediately subject to the escrow
        referred to in this Section 8 (to the extent the Stock is then so
        subject), shall be deposited with the Escrow Holder, and shall be
        included in the word "Stock" for purposes of this Agreement, and shall
        be subject to the Purchase Option with the same force and effect as the
        shares of Stock presently subject to this Agreement and the Purchase
        Option. While the total Option Price shall remain the same after each
        such event, the Option Price per share of Stock upon exercise of the
        Purchase Option shall be appropriately adjusted as determined by the
        Board of Directors of the Company.

               4. Legends. Upon consummation of this Amendment, Purchaser's
certificate representing the shares of Stock shall have endorsed thereon the
following legend:

                      "THE SECURITIES REPRESENTED BY THIS CERTIFICATE ARE
        SUBJECT TO THE TERMS AND CONDITIONS OF A CERTAIN FOUNDER/EMPLOYEE
        SHAREHOLDER AGREEMENT WHICH INCLUDES A REPURCHASE RIGHT ON THE SALE OF
        THE SECURITIES. COPIES OF THE AGREEMENT MAY BE OBTAINED UPON WRITTEN
        REQUEST TO THE SECRETARY OF THE CORPORATION.

               5. Effect of Amendment. The Founder Agreement, as amended hereby,
shall remain in full force and effect.

               6. Governing Law. This Amendment shall be governed by and
construed in


                                       8.


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accordance with the laws of the State of California without regard to the
conflicts of law provisions thereof.


                                       9.


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               IN WITNESS WHEREOF, the parties hereto have executed this
Amendment to the Founder Agreement as of the day and year first above written.

                                        ACCELERATED NETWORKS, INC.


                                        By: /s/ SURESH NIHALANI
                                           -------------------------------
                                               Suresh Nihalani
                                               President

                              Address:  5743 Corsa Avenue, Suite 221
                                        Westlake Village, CA 91362



                                        PURCHASER:


                                        /s/ SURESH NIHALANI
                                        ----------------------------------



                              Address:  c/o Accelerated Networks, Inc.
                                        5743 Corsa Avenue, Suite 221


                                      10.