AMENDED AND RESTATED 1997 NON-EMPLOYEE DIRECTOR STOCK OPTION PLAN

                                                                    EXHIBIT 10.2

                           EXCEL SWITCHING CORPORATION

                 AMENDED AND RESTATED 1997 NON-EMPLOYEE DIRECTOR
                                STOCK OPTION PLAN



         1. PURPOSE. This Non-Qualified Stock Option Plan, to be known as the
Amended and Restated 1997 Non-Employee Director Stock Option Plan (hereinafter,
the "Plan") is intended to promote the interests of Excel Switching Corporation
(hereinafter, the "Company") by providing an inducement to obtain and retain the
services of qualified persons who are not employees or officers of the Company
to serve as members of its Board of Directors (the "Board").

         2. AVAILABLE SHARES. The total number of shares of Common Stock, par
value $.01 per share, of the Company (the "Common Stock") for which options may
be granted under this Plan shall not exceed 225,000 shares, subject to
adjustment in accordance with paragraph 10 of this Plan. Shares subject to this
Plan are authorized but unissued shares or shares that were once issued and
subsequently reacquired by the Company. If any options granted under this Plan
are surrendered before exercise or lapse without exercise, in whole or in part,
the shares reserved therefor shall continue to be available under this Plan.

         3. ADMINISTRATION. This Plan shall be administered by the Board or by a
committee appointed by the Board (the "Committee"). In the event the Board fails
to appoint or refrains from appointing a Committee, the Board shall have all
power and authority to administer this Plan. In such event, the word "Committee"
wherever used herein shall be deemed to mean the Board. The Committee shall,
subject to the provisions of the Plan, have the power to construe this Plan, to
determine all questions hereunder, and to adopt and amend such rules and
regulations for the administration of this Plan as it may deem desirable. No
member of the Board or the Committee shall be liable for any action or
determination made in good faith with respect to this Plan or any option granted
under it.

         4. AUTOMATIC GRANT OF OPTIONS. Subject to the availability of shares
under this Plan and commencing on January 1, 2000, each person who is or becomes
a member of the Board and who is not an employee or officer of the Company (a
"Non-Employee Director") shall be automatically granted an option to purchase
1,250 shares of Common Stock of the Company on the first business day of
January, April, July and October of each fiscal year of the Company, provided
that such individual continues to be a Non-Employee Director on such date and
provided that as of such date, such individual has been a member of the Board
for at least one (1) year.



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The options to be granted under this paragraph 4 shall be the only options ever
to be granted at any time to such member under this Plan.

         5. OPTION PRICE. The purchase price of the stock covered by an option
granted pursuant to this Plan shall be 100% of the fair market value of such
shares on the day the option is granted. The option price will be subject to
adjustment in accordance with the provisions of paragraph 10 of this Plan. For
purposes of this Plan, if, at the time an option is granted under the Plan, the
Company's Common Stock is publicly traded, "fair market value" shall be
determined as of the last business day for which the prices or quotes discussed
in this sentence are available prior to the date such option is granted and
shall mean (i) the average (on that date) of the high and low prices of the
Common Stock on the principal national securities exchange on which the Common
Stock is traded, if the Common Stock is then traded on a national securities
exchange; or (ii) the last reported sale price (on that date) of the Common
Stock on the Nasdaq National Market, if the Common Stock is not then traded on a
national securities exchange; or (iii) the closing bid price (or average of bid
prices) last quoted (on that date) by an established quotation service for
over-the-counter securities, if the Common Stock is not reported on the Nasdaq
National Market List. If the Common Stock is not publicly traded at the time an
option is granted under the Plan, "fair market value" shall be deemed to be the
fair value of the Common Stock as determined by the Committee after taking into
consideration all factors which it deems appropriate, including, without
limitation, recent sale and offer prices of the Common Stock in private
transactions negotiated at arm's length. Notwithstanding the foregoing the fair
market value of the Common Stock for the grant of an option on the date of the
Company's Prospectus in connection with its initial public offering (the
"Offering") shall be equal to the price per share at which the Common Stock is
sold to the underwriters upon the Offering, without regard to any applicable
discounts or commissions provided to such underwriters.

         6. PERIOD OF OPTION. Unless sooner terminated in accordance with the
provisions of paragraph 8 of this Plan, an option granted hereunder shall expire
on the date which is ten (10) years after the date of grant of the option.

         7. VESTING OF SHARES AND NON-TRANSFERABILITY OF OPTIONS. (a) Options
granted under paragraph 4 of this Plan shall be fully vested and immediately
exercisable on the date such options are granted to the optionee.


         The number of shares as to which options may be exercised shall be
cumulative, so that once the option shall become exercisable as to any shares it
shall continue to be exercisable as to said shares, until expiration or
termination of the option as provided in this Plan.

                  (b) Notwithstanding subsection (a) of this paragraph 7, if an
optionee attends less than 75% of the Board meetings held in any fiscal year (a
"Default Year"), then the optionee shall forfeit his right to receive options in
the next fiscal year in 



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proportion to the percentage of Board meetings which the optionee actually
attended in the Default Year. If the optionee is required to forfeit his right
to receive future options, each successive quarterly option grant shall be
forfeited, in whole or in part, until the requisite number of options have been
forfeited. By way of illustration, if an optionee attends only 25% of the actual
meetings of the Board of Directors (whether regular or special) held in any
fiscal year, then the optionee shall forfeit the right to receive 75% of the
options to be granted in the next fiscal year (i.e., the grant of options on
January 1, April 1 and July 1 of the next fiscal year).

                  (c) TRANSFERABILITY. Any option granted pursuant to this Plan
shall be assignable or transferable by will, the laws of descent and
distribution, pursuant to a domestic relations order or in accordance with the
terms of the optionee's option agreement and only in compliance with the
provisions of the Securities Act of 1933, as amended.

         8.       TERMINATION OF OPTION RIGHTS.

                  (a) Subject to paragraph 8(c) below and except as may
otherwise be specified in the agreement relating to an option, in the event an
optionee ceases to be a member of the Board for any reason other than death or
permanent disability, any portion of an option which is then vested but has not
been exercised at the time the optionee so ceases to be a member of the Board
may be exercised, to the extent it is then vested, by the optionee at any time
prior to the scheduled expiration date of the option.

                  (b) Except as may otherwise be specified in the agreement
relating to an option, in the event that an optionee ceases to be a member of
the Board by reason of his or her death or permanent disability, any unexercised
options shall be exercisable by the optionee (or by the optionee's personal
representative, heir or legatee, in the event of death) at any time prior to the
scheduled expiration date of the option.

                  (c) Except as may otherwise be specified in the agreement
relating to an option, no portion of an option may be exercised if the optionee
is removed from the Board of Directors for any one of the following reasons: (i)
disloyalty, gross negligence, dishonesty or breach of fiduciary duty to the
Company; or (ii) the commission of an act of embezzlement, fraud or deliberate
disregard of the rules or policies of the Company; or (iii) the unauthorized
disclosure or misappropriation of any trade secret or confidential information
of the Company; or (iv) the commission of an act which constitutes unfair
competition with the Company or which induces any customer of the Company to
break a contract with the Company; or (v) the conduct of any activity on behalf
of any organization or entity which is a competitor of the Company (unless such
conduct is approved by a majority of the members of the Board of Directors).

         9. EXERCISE OF OPTION. Subject to the terms and conditions of this Plan
and the option agreements, an option granted hereunder shall, to the extent then
exercisable, 



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be exercisable in whole or in part by giving written notice to the Company by
mail, facsimile or in person addressed to Excel Switching Corporation, at its
principal executive offices, stating the number of shares with respect to which
the option is being exercised, accompanied by payment in full for such shares.
Payment may be (a) in United States dollars in cash or by check, (b) in whole or
in part in shares of the Common Stock of the Company already owned by the person
or persons exercising the option or shares subject to the option being exercised
(subject to such restrictions and guidelines as the Board may adopt from time to
time), valued at fair market value determined in accordance with the provisions
of paragraph 5 or (c) consistent with applicable law, through the delivery of an
assignment to the Company of a sufficient amount of the proceeds from the sale
of the Common Stock acquired upon exercise of the option and an authorization to
the broker or selling agent to pay that amount to the Company, which sale shall
be at the participant's direction at the time of exercise. There shall be no
such exercise at any one time as to fewer than one hundred (100) shares or all
of the remaining shares then purchasable by the person or persons exercising the
option if fewer than one hundred (100) shares. The Company's transfer agent
shall, on behalf of the Company, prepare a certificate or certificates
representing such shares acquired pursuant to exercise of the option, shall
register the optionee as the owner of such shares on the books of the Company
and shall cause the fully executed certificate(s) representing such shares to be
delivered to the optionee as soon as practicable after payment of the option
price in full. The holder of an option shall not have any rights of a
stockholder with respect to the shares covered by the option, except to the
extent that one or more certificates for such shares shall be delivered to him
or her upon the due exercise of the option.

         10. ADJUSTMENTS UPON CHANGES IN CAPITALIZATION AND OTHER EVENTS. Upon
the occurrence of any of the following events, an optionee's rights with respect
to options granted to him or her hereunder shall be adjusted as hereinafter
provided:

         (a) STOCK DIVIDENDS AND STOCK SPLITS. If the shares of Common Stock
      shall be subdivided or combined into a greater or smaller number of shares
      or if the Company shall issue any shares of Common Stock as a stock
      dividend on its outstanding Common Stock, the number of shares of Common
      Stock deliverable upon the exercise of options shall be appropriately
      increased or decreased proportionately, and appropriate adjustments shall
      be made in the purchase price per share to reflect such subdivision,
      combination or stock dividend.

         (b) RECAPITALIZATION ADJUSTMENTS. In the event of a reorganization,
      recapitalization, merger, consolidation, or any other change in the
      corporate structure or shares of the Company, to the extent permitted by
      Rule 16b-3 under the Securities Exchange Act of 1934, adjustments in the
      number and kind of shares authorized by this Plan and in the number and
      kind of shares covered by, and in the option price of outstanding options
      under this Plan necessary to maintain the proportionate interest of the
      optionee and preserve, without exceeding, the value of such option, shall
      be made. Notwithstanding the foregoing, no such adjustment shall be made
      which would, within the meaning of any applicable provisions of the
      Internal Revenue 



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      Code of 1986, as amended, constitute a modification, extension or renewal
      of any Option or a grant of additional benefits to the holder of an 
      Option.

         (c) ISSUANCES OF SECURITIES. Except as expressly provided herein, no
      issuance by the Company of shares of stock of any class, or securities
      convertible into shares of stock of any class, shall affect, and no
      adjustment by reason thereof shall be made with respect to, the number or
      price of shares subject to options. No adjustments shall be made for
      dividends paid in cash or in property other than securities of the
      Company.

         (d) ADJUSTMENTS. Upon the happening of any of the foregoing events, the
      class and aggregate number of shares set forth in paragraph 2 of this Plan
      that are subject to options which previously have been or subsequently may
      be granted under this Plan shall also be appropriately adjusted to reflect
      such events. The Board shall determine the specific adjustments to be made
      under this paragraph 10 and its determination shall be conclusive.

         11. RESTRICTIONS ON ISSUANCE OF SHARES. Notwithstanding the provisions
of paragraphs 4 and 9 of this Plan, the Company shall have no obligation to
deliver any certificate or certificates upon exercise of an option until one of
the following conditions shall be satisfied:

         (i) The issuance of shares with respect to which the option has been
      exercised is at the time of the issue of such shares effectively
      registered under applicable Federal and state securities laws as now in
      force or hereafter amended; or

         (ii) Counsel for the Company shall have given an opinion that the
      issuance of such shares is exempt from registration under Federal and
      state securities laws as now in force or hereafter amended; and the
      Company has complied with all applicable laws and regulations with respect
      thereto, including without limitation all regulations required by any
      stock exchange upon which the Company's outstanding Common Stock is then
      listed.

         12. LEGEND ON CERTIFICATES. The certificates representing shares issued
pursuant to the exercise of an option granted hereunder shall carry such
appropriate legend, and such written instructions shall be given to the
Company's transfer agent, as may be deemed necessary or advisable by counsel to
the Company in order to comply with the requirements of the Securities Act of
1933, as amended, or any state securities laws.

         13. REPRESENTATION OF OPTIONEE. If requested by the Company, the
optionee shall deliver to the Company written representations and warranties
upon exercise of the option that are necessary to show compliance with Federal
and state securities laws, including representations and warranties to the
effect that a purchase of shares under the 



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option is made for investment and not with a view to their distribution (as that
term is used in the Securities Act of 1933, as amended).

         14. OPTION AGREEMENT. Each option granted under the provisions of this
Plan shall be evidenced by an option agreement, which agreement shall be duly
executed and delivered on behalf of the Company and by the optionee to whom such
option is granted. The option agreement shall contain such terms, provisions and
conditions not inconsistent with this Plan as may be determined by the officer
executing it.

         15. TERMINATION AND AMENDMENT OF PLAN. Options may no longer be granted
under this Plan after September 15, 2007, and this Plan shall terminate when all
options granted or to be granted hereunder are no longer outstanding. The Board
may at any time terminate this Plan or make such modification or amendment
thereof as it deems advisable; PROVIDED, HOWEVER, that the Board may not,
without approval by the affirmative vote of the holders of a majority of the
shares of Common Stock present in person or by proxy and voting on such matter
at a meeting, (a) increase the maximum number of shares for which options may be
granted under this Plan (except by adjustment pursuant to Section 10), (b)
materially modify the requirements as to eligibility to participate in this
Plan, or (c) materially increase benefits accruing to option holders under this
Plan. Termination or any modification or amendment of this Plan shall not,
without consent of a participant, affect his or her rights under an option
previously granted to him or her.

         16. WITHHOLDING OF INCOME TAXES. Upon the exercise of an option, the
Company, in accordance with Section 3402(a) of the Internal Revenue Code, may
require the optionee to pay withholding taxes in respect of amounts considered
to be compensation includible in the optionee's gross income.

         17. COMPLIANCE WITH REGULATIONS. It is the Company's intent that the
Plan comply in all respects with Rule 16b-3 under the Securities Exchange Act of
1934 (or any successor or amended provision thereof) and any applicable
Securities and Exchange Commission interpretations thereof. If any provision of
this Plan is deemed not to be in compliance with Rule 16b-3, the provision shall
be null and void.

         18. GOVERNING LAW. The validity and construction of this Plan and the
instruments evidencing options shall be governed by the laws of the Commonwealth
of Massachusetts, without giving effect to the principles of conflicts of law
thereof.