Document:

<PAGE>   1
                                                                    Exhibit 10.1

                            UNISPHERE NETWORKS, INC.
                 AMENDED AND RESTATED 1999 STOCK INCENTIVE PLAN

1.   PURPOSE

     The purpose of this Amended and Restated 1999 Stock Incentive Plan (the
"Plan") of Unisphere Networks, Inc. ("Unisphere"), a Delaware corporation (the
"Company"), is to advance the interests of the Company's stockholders by
enhancing the Company's ability to attract, retain and motivate persons who make
(or are expected to make) important contributions to the Company by providing
such persons with equity ownership opportunities and performance-based
incentives and thereby better aligning the interest of such persons with those
of the Company's stockholders. Except where the context otherwise requires (but
in no event for purposes of Section 3), the term "Company" shall include any
present or future "subsidiary" corporations of Unisphere Solutions, Inc. as
defined in Section 424(f) of the Internal Revenue Code of 1986, as amended, and
any regulations promulgated thereunder (the "Code").

2.   ELIGIBILITY

     All of the Company's employees, officers, directors, secunded employees,
consultants and advisors are eligible to be granted options, restricted stock,
or other stock-based awards (each, an "Award") under the Plan. Any person who
has been granted an Award under the Plan shall be deemed a "Participant."

3.   ADMINISTRATION, DELEGATION

     (a) ADMINISTRATION BY BOARD OF DIRECTORS. The Plan will be administered by
the Board of Directors of the Company (the "Board"). The Board shall have
authority to grant Awards and to adopt, amend and repeal such administrative
rules, guidelines and practices relating to the Plan as it shall deem advisable.
The Board may correct any defect, supply any omission or reconcile any
inconsistency in the Plan or any Award. The Board may interpret the Plan and the
Awards, as well as any rules, guidelines and practices, with such interpretation
to be accorded the maximum deference permitted by law. All decisions by the
Board shall be made in the Board's sole discretion and shall be final and
binding on all persons having or claiming any interest in the Plan or in any
Award. No director or person acting pursuant to the authority delegated by the
Board shall be liable for any action or determination relating to or under the
Plan made in good faith.

     (b) RECOMMENDATIONS OF CHIEF EXECUTIVE OFFICER. The Chief Executive Officer
of the Company may make recommendations to the Board with respect to the grant
of Awards, and the Board shall give due consideration to such recommendations.
The express provisions of this Section 3(b) shall be of no force or effect at
such times as the Company has a class of equity securities which is registered
pursuant to Section 12 of the Exchange Act (as hereinafter defined).

     (c) APPOINTMENT OF COMMITTEES. To the extent permitted by applicable law,
the Board may delegate any or all of its powers under the Plan to one or more
committees or subcommittees of the Board (a "Committee"). If and when the
Company has a class of equity securities which is registered under the
Securities Exchange Act of 1934, as amended (the "Exchange Act"), any such
Committee shall consist of not less than two members, each member of which shall
be a "non-employee director" as defined in Rule 16b-3 promulgated under the
Exchange Act and shall (to the extent relief from the limitation of Section
162(m) of the Code is sought with respect to Awards) qualify as "outside
directors" for purposes of Section 162(m) of the Code. All references in the
Plan to the "Board" shall mean (i) the Board or (ii) a Committee to the extent
that the Board's powers or authority under the Plan have been delegated to such
Committee under this Section 3(c).

<PAGE>   2

4.   STOCK AVAILABLE FOR AWARDS

     (a) NUMBER OF SHARES. Subject to adjustment under Section 8(e) or 8(f),
Awards may be made under the Plan for an initial issuance of up to 19,690,839
shares of common stock, $0.01 par value per share ("Common Stock") of the
Company, to be increased annually on April 1st of each year, beginning in 2001,
by a number equal to the lesser of (i) 5% of the outstanding shares of Common
Stock on the last trading day in March of such year, (ii) 7,000,000 shares of
Common Stock, or (iii) such amount as is determined by the Board , all of which
may be available for Awards of Options (as hereinafter defined).The aggregate
number of shares available for grant under the Plan, subject to adjustment under
Section 8(e) or 8(f), shall be 34,690,839 shares. If any Award expires or is
terminated, surrendered or canceled without having been fully exercised or is
forfeited in whole or in part or results in any Common Stock not being issued,
the unused Common Stock covered by such Award shall again be available for the
grant of Awards under the Plan, subject, however, in the case of Incentive Stock
Options (as hereinafter defined), to any limitation required under the Code.
Shares issued under the Plan may consist in whole or in part of authorized but
unissued shares of treasury shares.

     (b) PER-PARTICIPANT LIMIT. Subject to adjustment under Section 8(e) or
8(f), for Awards granted at or after such time as the Company is subject to
Section 162(m) of the Code, the maximum number of shares with respect to which
an Award may be granted to any Participant under the Plan shall be 2,720,000 per
calendar year. The per-Participant limit described in this Section 4(b) shall be
construed and applied consistently with Section 162(m) of the Code.

5.   STOCK OPTIONS

     (a) GENERAL. The Board may grant options to purchase Common Stock (each, an
"Option") and determine the number of shares of Common Stock to be covered by
each Option, the exercise price of each Option and the conditions and
limitations applicable to the exercise of each Option, including conditions
relating to applicable federal or state securities laws, as it considers
necessary or advisable. An Option which is not intended to be an Incentive Stock
Option (as hereinafter defined) shall be designated a "Nonstatutory Stock
Option".

     (b) INCENTIVE STOCK OPTIONS. An Option that the Board intends to be an
"incentive stock option" as defined in Section 422 of the Code (an "Incentive
Stock Option") shall be identified as such, shall only be granted to employees
of the Company and shall be subject to and shall be construed consistently with
the requirements of Section 422 of the Code. The Company shall have no liability
to a Participant, or any other party, if an Option (or any part thereof) which
is intended to be an Incentive Stock Option is not an Incentive Stock Option.

     (c) EXERCISE PRICE. The Board shall establish the exercise price at the
time each Option is granted and specify it in the applicable Option award
agreement (the "Option Award Agreement"). In the case of any Option intended to
qualify for special relief for options from the limitation of Section 162(m) of
the Code, the exercise price of such Option shall be not less than 100% of the
Fair Market Value of a share of Common Stock on the day the Option is granted;
and the exercise price with respect to each Incentive Stock Option shall not be
less than 100% (or 110%, in the case of an individual described in Section
422(b)(6) of the Code (relating to certain 10% owners)) of the Fair Market Value
(as hereinafter defined) of a share of Common Stock on the day the Option is
granted.

     For purposes of the Plan, "Fair Market Value" per share of Common Stock as
of a particular date means (i) if shares of Common Stock (including, for
purposes of this paragraph, American Depository Receipts (or any similar
security) in respect thereof) are then listed on a national stock exchange, the
closing sales price per share of Common Stock on the exchange for the last
preceding date on which there was a sale of shares of Common Stock on such
exchange, as determined by the Board, (ii) if shares of Common Stock are not
then listed on a national stock exchange but are then traded on an
over-the-counter

                                       2
<PAGE>   3

market, the average of the closing bid and asked prices for the shares of Common
Stock in such over-the-counter market for the last preceding date on which there
was a sale of such shares of Common Stock in such market, as determined by the
Board, or (iii) if shares of Common Stock are not then listed on a national
stock exchange or traded on an over-the-counter market, such value as the Board
in its discretion may in good faith determine; provided that, where the shares
of Common Stock are so listed or traded, the Board may make such discretionary
determinations where the shares of Common Stock have not been traded for 10
trading days.

     (d) DURATION OF OPTIONS. Unless earlier expired, forfeited or otherwise
terminated, each Option shall expire in its entirety upon the tenth anniversary
of the date of grant or shall have such other term as is set forth in the
applicable Option Award Agreement (except that, in the case of an individual
described in Section 422(b)(6) of the Code (relating to certain 10% owners) who
is granted an Incentive Stock Option, the term of such Option shall be no more
than five years from the date of grant).

     (e) EXERCISE OF OPTION. Options may be exercised only by delivery to the
Company of a written notice of exercise signed by the proper person together
with payment in full as specified in Section 5(h) for the number of shares for
which the Option is exercised.

     (f) INCENTIVE STOCK OPTION ANNUAL LIMITATION. The aggregate Fair Market
Value, determined as of the date an Option is granted, of the Common Stock for
which any Participant may be awarded Incentive Stock Options which are first
exercisable by the Participant during any calendar year under the Plan (or any
other stock option plan required to be taken into account under Section 422(d)
of the Code) shall not exceed $100,000.

     (g) DISQUALIFYING DISPOSITION. If shares of Common Stock acquired upon
exercise of an Incentive Stock Option are disposed of in a disqualifying
disposition within the meaning of Section 422 of the Code by a Participant or,
if applicable, a permitted successor of the Participant, prior to the expiration
of either two years from the date of grant of such Option or one year from the
transfer of shares of Common Stock to the Participant pursuant to the exercise
of such Option, or in any other disqualifying disposition within the meaning of
Section 422 of the Code, such Participant, or, if applicable, such successor,
shall notify the Company in writing as soon as practicable thereafter of the
date and terms of such disposition and, if the Company (or any affiliate
thereof) thereupon has a tax-withholding obligation, shall pay to the Company
(or such affiliate) an amount equal to any withholding tax the Company (or
affiliate) is required to pay as a result of the disqualifying disposition.

     (h) PAYMENT UPON EXERCISE. Common Stock purchased upon the exercise of an
Option granted under the Plan shall be paid as follows:

          (1) in cash or by check, payable to the order of the Company;

          (2) to the extent permitted by the Board in an Option Award Agreement
or otherwise, by delivery of an irrevocable and unconditional undertaking by a
creditworthy broker to deliver promptly to the Company sufficient funds to pay
the exercise price, or delivery by the Participant to the Company of a copy of
irrevocable and unconditional instructions to a creditworthy broker to deliver
promptly to the Company cash or a check sufficient to pay the exercise price;

          (3) to the extent permitted by the Board in an Option Award Agreement
or otherwise, by (A) delivery of shares of Common Stock owned by the Participant
valued at their Fair Market Value, which Common Stock was owned by the
Participant at least six months prior to such delivery, (B) delivery of a
promissory note of the Participant to the Company on terms determined by the
Board, or (C) payment of such other lawful consideration as the Board may
determine; or

          (4) by any combination of the above permitted forms of payment.

                                       3

<PAGE>   4

6.   RESTRICTED STOCK

     (a) GRANTS. The Board may grant Awards entitling recipients to acquire
shares of Common Stock, subject to the right of the Company to require
forfeiture of such shares (or to repurchase all or part of such shares at their
issue price or other stated or formula price, if applicable) from the recipient
in the event that conditions specified by the Board in the applicable Award are
not satisfied prior to the end of the applicable restriction period or periods
established by the Board for such Award (each, a "Restricted Stock Award").

     (b) TERMS AND CONDITIONS. The Board shall determine the terms and
conditions of any such Restricted Stock Award, including the conditions for
repurchase (or forfeiture) and the issue price, if any. Any stock certificates
issued in respect of a Restricted Stock Award shall be registered in the name of
the Participant and, unless otherwise determined by the Board, deposited by the
Participant, together with a stock power endorsed in blank, with the Company (or
its designee). At the expiration of the applicable restriction periods, the
Company (or such designee) shall deliver the certificates no longer subject to
such restrictions to the Participant or if the Participant has died, to the
beneficiary designated, in a manner determined by the Board, by a Participant to
receive amounts due or exercise rights of the Participant in the event of the
Participant's death (the "Designated Beneficiary"). In the absence of an
effective designation by a Participant, Designated Beneficiary shall mean the
Participant's estate.

7.   OTHER STOCK-BASED AWARDS

     The Board shall have the right to grant other Awards based upon the Common
Stock having such terms and conditions as the Board may determine, including the
grant of shares based upon certain conditions, the grant of securities
convertible into Common Stock and the grant of stock appreciation rights.

8.   GENERAL PROVISIONS APPLICABLE TO AWARDS

     (a) TRANSFERABILITY OF AWARDS. Except as the Board may otherwise determine
or provide in an Award, Awards shall not be sold, assigned, transferred, pledged
or otherwise encumbered by the person to whom they are granted, either
voluntarily or by operation of law, except by will or the laws of descent and
distribution, and, during the life of the Participant, shall be exercisable only
by the Participant. References to a Participant, to the extent relevant in the
context, shall include references to authorized transferees.

     (b) DOCUMENTATION. Each Award under the Plan shall be evidenced by a
written instrument in such form as the Board shall determine. Each Award may
contain terms and conditions in addition to those set forth in the Plan. The
certificates for shares issued hereunder may include any legend which the Board
deems appropriate to reflect any restriction on transfer hereunder or under an
Award or as the Board may otherwise deem appropriate. Without limiting any other
provision of the Plan, each Participant shall take whatever additional actions
and execute whatever additional documents the Company may in its reasonable
judgment deem necessary or advisable in order to carry or effect one or more of
the obligations or restrictions imposed on the Participant pursuant to the
express provisions of the Plan or any Award.

     (c) BOARD DISCRETION. Except as otherwise provided by the Plan, each type
of Award may be made alone or in addition or in relation to any other type of
Award. The terms of each type of Award need not be identical, and the Board need
not treat Participants uniformly.

     (d) TERMINATION OF STATUS. The Board shall determine the effect on an Award
of the disability, death, retirement, authorized leave of absence or other
change in the employment or other status of a Participant and the extent to
which, and the period during which, the Participant, the

                                       4

<PAGE>   5

Participant's legal representative, conservator, guardian or Designated
Beneficiary may exercise rights under the Award.

     (e)   CERTAIN ACQUISITION EVENTS.

               (1) ASSUMPTION OF OPTIONS AND AWARDS. Upon the occurrence of an
Acquisition Event (as defined below), or the execution by the Company of any
agreement with respect to an Acquisition Event, the Board may take any one or
more of the following actions, or any other action not inconsistent with the
terms of the Plan, with respect to then outstanding Awards: (i) provide that
outstanding Options (and stock appreciation rights) shall be assumed, or
equivalent Options (and stock appreciation rights) shall be substituted, by the
acquiring or succeeding corporation (or an affiliate thereof), provided that any
such Options substituted for Incentive Stock Options shall satisfy, in the
determination of the Board, the requirements of Section 424(a) of the Code; or
(ii) provide that any other outstanding stock-based Awards shall be assumed, or
equivalent Awards shall be substituted, by the acquiring or succeeding
corporation (or an affiliate thereof).

     An "Acquisition Event" shall mean: (a) any merger or consolidation which
results in the voting securities of the Company outstanding immediately prior
thereto representing immediately thereafter (either by remaining outstanding or
by being converted into voting securities of the surviving or acquiring entity)
less than a majority of the combined voting power of the voting securities of
the Company or such surviving or acquiring entity outstanding immediately after
such merger or consolidation; (b) any sale of all or substantially all of the
assets of the Company, if the Company owns less than a majority of the combined
voting power of the voting securities of the acquiring entity or other person;
or (c) the sale of shares of capital stock of the Company, in a single
transaction or series of related transactions, representing at least 80% of the
voting power of the voting securities of the Company, if the Company owns less
than a majority of the combined voting power of the voting securities of the
acquiring entity or other person. Notwithstanding the foregoing, (x) a merger or
consolidation with a Siemens Entity (as defined below) shall not be an
Acquisition Event under clause (a) of the foregoing sentence, and (y) sales to a
Siemens Entity shall be disregarded under clauses (b) and (c) of the foregoing
sentence. For these purposes, a "Siemens Entity" shall be any entity which is
controlling, controlled by or under common control with Siemens AG; provided
that, without limiting the generality of the foregoing, the term "Siemens
Entity" shall expressly include any entity the combined voting power of the
voting securities of which is owned, directly or indirectly, 50% or more by
Siemens AG.

               (2) ACCELERATION, ETC. Unless otherwise provided in the Option
Award Agreement or the stock restriction agreement relating to a Restricted
Stock Award, or in the award agreement relating to other stock-based awards
under Section 7, as applicable, upon the occurrence of an Acquisition Event, (i)
in case of an Option for shares with respect to which the Option (or stock
appreciation right) is not then exercisable (but only to the extent the Option
(or stock appreciation right) may in the future become exercisable and is
otherwise then outstanding) the Option shall be exercisable for the number of
shares of Common Stock as is scheduled to apply on the date 12 months after the
closing of the Acquisition Event, provided, however, that with respect to any
Option granted to a non-employee Director of the Company, such Option shall
become immediately exercisable in full, (ii) all restrictions relating to
outstanding shares then subject to restrictions pursuant to the Restricted Stock
Award shall lapse with respect to the number of shares which are scheduled to
become free of restriction during the 12 months to follow the closing of the
Acquisition Event and (iii) vesting conditions applicable to Awards not covered
by clause (i) or (ii) shall lapse to the extent that they would be scheduled to
lapse during the 12 months to follow the closing of the Acquisition Event. In
addition, upon the occurrence of an Acquisition Event, or the execution by the
Company of an agreement with respect to an Acquisition Event, the Board may take
any one of the following actions with respect to then outstanding Awards: (i)
upon written notice to the Participants, provide that all then unexercised
Options (and stock appreciation rights) will become exercisable in full as of a
specified time (the "Acceleration Time") prior to the

                                       5

<PAGE>   6

Acquisition Event and will terminate immediately prior to the consummation of
such Acquisition Event, except to the extent exercised by the Participants
between the Acceleration Time and the consummation of the Acquisition Event;
(ii) provide that all Restricted Stock Awards then outstanding shall become free
of all restrictions prior to the consummation of the Acquisition Event; (iii) in
the event of an Acquisition Event under the terms of which holders of Common
Stock will receive upon consummation thereof a cash payment for each share of
Common Stock surrendered pursuant to such Acquisition Event (the "Acquisition
Price"), provide that all outstanding Options (and stock appreciation rights)
shall terminate upon consummation of such Acquisition Event and each Participant
shall receive, in exchange therefor, a cash payment equal to the amount (if any)
by which (A) the Acquisition Price multiplied by the number of shares of Common
Stock subject to such outstanding Options (or stock appreciation rights)
(whether or not then exercisable), exceeds (B) the aggregate exercise price of
such Options (or stock appreciation rights); and (iv) provide that any other
stock-based Awards outstanding shall become exercisable, realizable or vested in
full, or shall be free of all conditions or restrictions, as applicable to each
such Award, prior to the consummation of the Acquisition Event.

     (f) CERTAIN CHANGES IN CAPITAL STRUCTURE.

               (1) IN GENERAL. If (i) the Company shall at any time be involved
in a merger, consolidation, dissolution, liquidation, reorganization, exchange
of shares, sale of all or substantially all of the assets or stock of the
Company or a transaction similar thereto, (ii) any stock dividend, stock split,
reverse stock split, stock combination, reclassification, recapitalization or
other similar change in the capital structure of the Company, or any
distribution to holders of Common Stock other than cash dividends, shall occur
or (iii) any other event shall occur which in the judgment of the Board
necessitates action by way of adjusting the terms of the outstanding Awards,
then:

          (x) the maximum aggregate number of shares of Common Stock which may
          be made subject to Options under the Plan, the maximum aggregate
          number and kind of shares of Restricted Stock that may be granted
          under the Plan and the maximum amount of Awards generally which may be
          granted under the Plan may be appropriately adjusted by the Committee
          in its discretion; and

          (y) the Board may take any such action as in its judgment shall be
          necessary to preserve the Participants' rights in their respective
          Awards substantially proportionate to the rights existing in such
          Awards prior to such event, including, without limitation, adjustments
          in (A) the number of Options (and stock appreciation rights) granted,
          (B) the number and kind of shares or other property to be distributed
          in respect of Options (and stock appreciation rights) (if and as
          applicable) and (C) the Option exercise price (and the exercise price
          of stock appreciation rights).

If this Section 8(f) applies and Section 8(e) also applies to any event, then
Section 8(e) shall be applicable, and this Section 8(f) shall not be applicable
to the extent inconsistent with the actions taken and results occurring in
accordance with Section 8(e).

               (2) ASSUMPTION OF AWARDS UPON CERTAIN EVENTS. The Board may grant
Awards under the Plan in substitution for stock and stock-based awards held by
employees or another corporation who become employees of the Company as a result
of a merger or consolidation of the employing corporation with the Company or
the acquisition by the Company of property or stock of the employing
corporation. The substitute Awards shall be granted on such terms and conditions
as the Board considers appropriate in the circumstances.

               (3) RESTRICTED STOCK. Any shares or other securities distributed
to a Participant with respect to Restricted Stock shall be subject to the
restrictions and requirements imposed by Section 6, including depositing the
certificates therefor with the Company together with a stock power

                                       6

<PAGE>   7

as provided in Section 6. In addition, if the Company shall be consolidated or
merged with another corporation, each Participant who has received Restricted
Stock that is then subject to restrictions imposed by Section 6 may be required
to deposit with the successor corporation the certificates for the stock or
securities or the other property that the Participant is entitled to receive by
reason of ownership of Restricted Stock in a manner consistent with Section 6,
and such stock, securities or other property shall become subject to the
restrictions and requirements imposed by Section 6.

     (g) RIGHT OF FIRST REFUSAL; RIGHT OF REPURCHASE. At the time of grant of an
Award, the Board may provide in connection with any Award under the Plan that
shares of Common Stock received in connection with Awards shall be subject to
(i) a right of first refusal pursuant to which the Company shall be entitled to
purchase such shares in the event of a prospective sale of shares of Common
Stock, subject to such terms and conditions as the Board may specify at the time
of the grant of the Award or (if permitted by the Award) thereafter, or (ii) a
right of repurchase, pursuant to which the Company shall be entitled to purchase
such shares of Common Stock at a price determined by, or under a formula set by,
the Board at the time of grant or (if permitted by the Award) thereafter,
subject to such other terms and conditions as the Board may specify at the time
of grant.

     (h) WITHHOLDING. Each Participant shall pay to the Company, or make
provision satisfactory to the Board for payment of, any taxes required by law to
be withheld in connection with Awards to such Participant no later than the date
of the event creating the tax liability. The Board may allow Participants to
satisfy such tax obligations in whole or in part in shares of Common Stock,
including shares retained from the Award creating the tax obligation, valued at
their Fair Market Value. The Company may, to the extent permitted by law, deduct
any such tax obligations from any payment of any kind otherwise due to a
Participant. Notwithstanding anything contained in the Plan to the contrary, the
Participant's satisfaction of any tax-withholding requirements imposed by the
Board shall be a condition precedent to the Company's obligation as may
otherwise be provided hereunder to provide shares of Common Stock to the
Participant and to the release of any restrictions as may otherwise be provided
hereunder, as applicable; and the applicable Option or Restricted Stock (or
other stock-based Awards) shall be forfeited upon the failure of the Participant
to satisfy such requirements with respect to, as applicable, (i) the exercise of
the Option, (ii) the lapsing of restrictions on the Restricted Stock (or other
income-recognition event) or (iii) distributions in respect of any other
stock-based Awards.

     (i) AMENDMENT OF AWARD. The Board may amend, modify or terminate any
outstanding Award, including but not limited to, substituting therefor another
Award of the same or a different type, changing the date of exercise or
realization, and converting an Incentive Stock Option to a Nonstatutory Stock
Option, provided that the Participant's consent to such action shall be required
unless the Board determines that the action, taking into account any related
action, would not materially and adversely affect the Participant.

     (j) CONDITIONS ON DELIVERY OF STOCK.

          (1) The obligation of the Company to sell shares of Common Stock with
respect to an Award shall be subject to all applicable laws, rules and
regulations, including all applicable federal and state securities laws, and the
obtaining of all such approvals by governmental agencies as may be deemed
necessary or appropriate by the Board.

          (2) The Board may make such changes to the Plan as may be necessary or
appropriate to comply with the rules and regulations of any government authority
or to obtain tax benefits applicable to stock options.

          (3) Each grant of an Award (or issuance of shares of Common Stock in
respect thereof) is subject to the requirement that, if at any time the Board
determines, in its discretion, that the listing, registration or qualification
of shares of Common Stock issuable pursuant to the Plan is

                                       7
<PAGE>   8

required by any securities exchange or under any state or federal law, or the
consent or approval of any governmental regulatory body is necessary or
desirable as a condition of, or in connection with, the grant of an Award (or
the issuance of shares of Common Stock in respect thereof), no payment shall be
made or share issued or grant of Restricted Stock made, in whole or in part,
unless listing, registration, qualification, consent or approval has been
effected or obtained free of any conditions in a manner acceptable to the Board.

          (4) In the event that the disposition of stock acquired pursuant to
the Plan is not covered by a then current registration statement under the
Securities Act of 1933, as amended (the "Securities Act"), and is not otherwise
exempt from such registration, such shares of Common Stock shall be restricted
against transfer to the extent required under the Securities Act, and the Board
may require any individual receiving shares of Common Stock pursuant to the
Plan, as a condition precedent to receipt of such shares of Common Stock, to
represent to the Company in writing that the shares of Common Stock acquired by
such individual are acquired for investment only and not with a view to
distribution and that such shares of Common Stock will be disposed of only if
registered for sale under the Securities Act or if there is an available
exemption for such disposition.

     (k) ACCELERATION. The Board may at any time provide that any Options shall
become immediately exercisable in full or in part, that any Restricted Stock
Awards shall be free of all restrictions or that any other stock-based Awards
may become exercisable in full or in part or free of some or all restrictions or
conditions, or otherwise realizable in full or in part, as the case may be.

9.   MISCELLANEOUS

     (a) NO RIGHT TO EMPLOYMENT OR OTHER STATUS. No person shall have any claim
or right to be granted an Award, and the grant of an Award shall not be
construed as giving a Participant the right to continued employment or any other
relationship with the Company. The Company expressly reserves the right at any
time to dismiss or otherwise terminate its relationship with a Participant free
from any liability or claim under the Plan, except as expressly provided in the
applicable Award.

     (b) NO RIGHTS AS STOCKHOLDER. Subject to the provisions of the applicable
Award, no Participant or Designated Beneficiary shall have any rights as a
stockholder with respect to any shares of Common Stock to be distributed with
respect to an Award until becoming the record holder of such shares.

     (c) NOTICES. All notices under the Plan shall be in writing, and if to the
Company, shall be delivered to the Board or mailed to its principal office,
addressed to the attention of the Board; and if to the Participant, shall be
delivered personally, sent by facsimile transmission or mailed to the
Participant at the address appearing in the records of the Company. Such
addresses may be changed at any time by written notice to the other party given
in accordance with this Section 9(c).

     (d) EFFECTIVE DATE AND TERM OF PLAN. The Plan shall become effective on the
date on which it is adopted by the Board. No Awards shall be granted under the
Plan after the completion of five years from the earlier of (i) the date on
which the Plan was adopted by the Board or (ii) the date the Plan was approved
by the Company's stockholders, but Awards previously granted may remain
outstanding beyond that date.

     (e) AMENDMENT OF PLAN. The Board may amend, suspend or terminate the Plan
or any portion thereof at any time.

     (f) CAPTIONS. The use of captions in this Plan is for convenience. The
captions are not intended to provide substantive rights.

                                       8

<PAGE>   9

     (g) GOVERNING LAW. The provisions of the Plan and all Awards made hereunder
shall be governed by and interpreted in accordance with the laws of the
Commonwealth of Massachusetts, without reference to principles of conflict of
laws.

                                       9<PAGE>   1
                                                                    Exhibit 10.2

                            UNISPHERE NETWORKS, INC.

                        2000 EMPLOYEE STOCK PURCHASE PLAN

      The purpose of this Plan is to provide eligible employees of Unisphere
Networks, Inc. (the "Company") and certain of its subsidiaries with
opportunities to purchase shares of the Company's common stock, $.01 par value
(the "Common Stock"). This Plan is intended to qualify as an "employee stock
purchase plan" as defined in Section 423 of the Internal Revenue Code of 1986,
as amended (the "Code"), and the regulations promulgated thereunder, and shall
be interpreted consistent therewith.

      The number of shares of Common Stock covered by this Plan shall initially
be 600,000. On January 1st of each year, beginning in 2001, the number of shares
of Common Stock covered by this Plan shall be increased by 0.7% of the then
outstanding number of shares of Common Stock, or such lesser amount as is
determined by the Company's Board of Directors (the "Board"). The aggregate
number of shares that may be issued under this plan is 5,000,000.

      1.    ADMINISTRATION. The Plan will be administered by the Board or by a
Committee appointed by the Board (the "Committee"). The Board or the Committee
has authority to make rules and regulations for the administration of the Plan
and its interpretation and decisions with regard thereto shall be final and
conclusive.

      2.    ELIGIBILITY. All employees of the Company, including Directors who
are employees, and all employees of any subsidiary of the Company (as defined in
Section 424(f) of the Code) designated by the Board or the Committee from time
to time (a "Designated Subsidiary"), are eligible to participate in any one or
more of the offerings of Options (as defined in Section 9) to purchase Common
Stock under the Plan provided that:

            (a)   they are customarily employed by the Company or a Designated
Subsidiary for more than 20 hours a week and for more than five months in a
calendar year; and

            (b)   they are employees of the Company or a Designated Subsidiary
on the first day of the applicable Plan Period (as defined below).

      No employee may be granted an option hereunder if such employee,
immediately after the option is granted, owns 5% or more of the total combined
voting power or value of the stock of the Company or any subsidiary. For
purposes of the preceding sentence, the attribution rules of Section 424(d) of
the Code shall apply in determining the stock ownership of an employee, and all
stock which the employee has a contractual right to purchase shall be treated as
stock owned by the employee.

      3.    OFFERINGS. The Company will make one or more offerings ("Offerings")
to employees to purchase stock under this Plan. Offerings will begin each April
1 and October 1, or the first business day thereafter (the "Offering
Commencement Dates"). Each Offering Commencement Date will begin a six month
period (a "Plan Period") during which payroll

<PAGE>   2

deductions will be made and held for the purchase of Common Stock at the end of
the Plan Period. The Board or the Committee may, at its discretion, choose a
different Plan Period of twelve (12) months or less for any Offering.
Notwithstanding anything to the contrary, the first Plan Period shall begin on
the date on which the Securities and Exchange Commission declares effective (the
"Effective Date") the registration statement on Form S-1 (the "Registration
Statement") for the initial public offering of the Company's Common Stock (the
"First Plan Period") and shall end on the last business day on or before October
1, 2001, and the April 1, 2001 Plan Period shall commence on April 1, 2001 and
shall overlap with the First Plan Period, provided that only employees who were
not employees of the Company on the Effective Date shall be eligible to
participate in the April 1, 2001 Plan Period.

      4.    PARTICIPATION. An employee eligible on the Offering Commencement
Date of any Offering may participate in such Offering by completing and
forwarding a payroll deduction authorization form to the employee's appropriate
payroll office at least 10 days prior to the applicable Offering Commencement
Date. The form will authorize a regular payroll deduction from the Compensation
received by the employee during the Plan Period. Unless an employee files a new
form or withdraws from the Plan, his deductions and purchases will continue at
the same rate for future Offerings under the Plan as long as the Plan remains in
effect. The term "Compensation" means the amount of money reportable on the
employee's Federal Income Tax Withholding Statement, excluding overtime, shift
premium, incentive or bonus awards, allowances and reimbursements for expenses
such as relocation allowances for travel expenses, income or gains on the
exercise of Company stock options or stock appreciation rights, and similar
items, whether or not shown on the employee's Federal Income Tax Withholding
Statement, but including, in the case of salespersons, sales commissions to the
extent determined by the Board or the Committee.

      5.    DEDUCTIONS. The Company will maintain payroll deduction accounts for
all participating employees. With respect to any Offering made under this Plan,
an employee may authorize a payroll deduction in any dollar amount up to a
maximum of 10% of the Compensation he or she receives during the Plan Period or
such shorter period during which deductions from payroll are made. The minimum
payroll deduction is such percentage of compensation as may be established from
time to time by the Board or the Committee.

      No employee may be granted an Option (as defined in Section 9) which
permits his rights to purchase Common Stock under this Plan and any other
employee stock purchase plan (as defined in Section 423(b) of the Code) of the
Company and its subsidiaries, to accrue at a rate which exceeds $25,000 of the
fair market value of such Common Stock (determined at the Offering Commencement
Date of the Plan Period) for each calendar year in which the Option is
outstanding at any time.

      6.    DEDUCTION CHANGES. An employee may decrease or discontinue his
payroll deduction once during any Plan Period, by filing a new payroll deduction
authorization form. However, an employee may not increase his payroll deduction
during a Plan Period. If an employee elects to discontinue his payroll
deductions during a Plan Period, but does not elect to withdraw his funds
pursuant to Section 8 hereof, funds deducted prior to his election to
discontinue will be applied to the purchase of Common Stock on the Exercise Date
(as defined below).

                                      -2-

<PAGE>   3

      7.    INTEREST. Interest will not be paid on any employee accounts, except
to the extent that the Board or the Committee, in its sole discretion, elects to
credit employee accounts with interest at such per annum rate as it may from
time to time determine.

      8.    WITHDRAWAL OF FUNDS. An employee may at any time prior to the close
of business on the last business day in a Plan Period and for any reason
permanently draw out the balance accumulated in the employee's account and
thereby withdraw from participation in an Offering. Partial withdrawals are not
permitted. The employee may not begin participation again during the remainder
of the Plan Period. The employee may participate in any subsequent Offering in
accordance with terms and conditions established by the Board or the Committee.

      9.    PURCHASE OF SHARES. On the Offering Commencement Date of each Plan
Period, the Company will grant to each eligible employee who is then a
participant in the Plan an option ("Option") to purchase on the last business
day of such Plan Period (the "Exercise Date"), at the Option Price hereinafter
provided for, the largest number of whole shares of Common Stock of the Company
as does not exceed the number of shares determined by multiplying $2,083 by the
number of full months in the Offering Period and dividing the result by the
closing price (as defined below) on the Offering Commencement Date of such Plan
Period.

      The purchase price for each share purchased will be 85% of the closing
price of the Common Stock on (i) the first business day of such Plan Period or
(ii) the Exercise Date, whichever closing price shall be less. Such closing
price shall be (a) the closing price on any national securities exchange on
which the Common Stock is listed, (b) the closing price of the Common Stock on
the Nasdaq National Market or (c) the average of the closing bid and asked
prices in the over-the-counter-market, whichever is applicable, as published in
THE WALL STREET JOURNAL; provided that, with respect to the First Plan Period,
the closing price on the Offering Commencement Date shall be the offering price
to the public set forth in the final prospectus included within the Registration
Statement. If no sales of Common Stock were made on such a day, the price of the
Common Stock for purposes of clauses (a) and (b) above shall be the reported
price for the next preceding day on which sales were made.

      Each employee who continues to be a participant in the Plan on the
Exercise Date shall be deemed to have exercised his Option at the Option Price
on such date and shall be deemed to have purchased from the Company the number
of full shares of Common Stock reserved for the purpose of the Plan that his
accumulated payroll deductions on such date will pay for, but not in excess of
the maximum number determined in the manner set forth above.

      Any balance remaining in an employee's payroll deduction account at the
end of a Plan Period will be automatically refunded to the employee, except that
any balance which is less than the purchase price of one share of Common Stock
will be carried forward into the employee's payroll deduction account for the
following Offering, unless the employee elects not to participate in the
following Offering under the Plan, in which case the balance in the employee's
account shall be refunded.

      10.   ISSUANCE OF CERTIFICATES. Certificates representing shares of Common
Stock purchased under the Plan may be issued only in the name of the employee,
in the name of the employee and another person of legal age as joint tenants
with rights of survivorship, or (in the

                                      -3-

<PAGE>   4

Company's sole discretion) in the name of a brokerage firm, bank or other
nominee holder designated by the employee. The Company may, in its sole
discretion and in compliance with applicable laws, authorize the use of book
entry registration of shares in lieu of issuing stock certificates.

      11.   RIGHTS ON RETIREMENT, DEATH OR TERMINATION OF EMPLOYMENT. In the
event of a participating employee's termination of employment prior to the last
business day of a Plan Period, no payroll deduction shall be taken from any pay
due and owing to an employee and the balance in the employee's account shall be
paid to the employee or, in the event of the employee's death, (a) to a
beneficiary previously designated in a revocable notice signed by the employee
(with any spousal consent required under state law) or (b) in the absence of
such a designated beneficiary, to the executor or administrator of the
employee's estate or (c) if no such executor or administrator has been appointed
to the knowledge of the Company, to such other person(s) as the Company may, in
its discretion, designate. If, prior to the last business day of the Plan
Period, the Designated Subsidiary by which an employee is employed shall cease
to be a subsidiary of the Company, or if the employee is transferred to a
subsidiary of the Company that is not a Designated Subsidiary, the employee
shall be deemed to have terminated employment for the purposes of this Plan.

      12.   OPTIONEES NOT STOCKHOLDERS. Neither the granting of an Option to an
employee nor the deductions from his pay shall constitute such employee a
stockholder of the shares of Common Stock covered by an Option under this Plan
until such shares have been purchased by and issued to him.

      13.   RIGHTS NOT TRANSFERABLE. Rights under this Plan are not transferable
by a participating employee other than by will or the laws of descent and
distribution, and are exercisable during the employee's lifetime only by the
employee.

      14.   APPLICATION OF FUNDS. All funds received or held by the Company
under this Plan may be combined with other corporate funds and may be used for
any corporate purpose.

      15.   ADJUSTMENT IN CASE OF CHANGES AFFECTING COMMON STOCK. In the event
of a subdivision of outstanding shares of Common Stock, or the payment of a
dividend in Common Stock, the number of shares approved for this Plan, and the
share limitation set forth in Section 9, shall be increased proportionately, and
such other adjustment shall be made as may be deemed equitable by the Board or
the Committee. In the event of any other change affecting the Common Stock, such
adjustment shall be made as may be deemed equitable by the Board or the
Committee to give proper effect to such event.

      16.   MERGER. If the Company shall at any time merge or consolidate with
another corporation and the holders of the capital stock of the Company
immediately prior to such merger or consolidation continue to hold at least 80%
by voting power of the capital stock of the surviving corporation ("Continuity
of Control"), the holder of each Option then outstanding will thereafter be
entitled to receive at the next Exercise Date upon the exercise of such Option
for each share as to which such Option shall be exercised the securities or
property which a holder of one share of the Common Stock was entitled to upon
and at the time of such merger or consolidation, and the Board or the Committee
shall take such steps in connection with such

                                      -4-

<PAGE>   5

merger or consolidation as the Board or the Committee shall deem necessary to
assure that the provisions of Section 15 shall thereafter be applicable, as
nearly as reasonably may be, in relation to the said securities or property as
to which such holder of such Option might thereafter be entitled to receive
thereunder.

      In the event of a merger or consolidation of the Company with or into
another corporation which does not involve Continuity of Control, or of a sale
of all or substantially all of the assets of the Company while unexercised
Options remain outstanding under the Plan, (a) subject to the provisions of
clauses (b) and (c), after the effective date of such transaction, each holder
of an outstanding Option shall be entitled, upon exercise of such Option, to
receive in lieu of shares of Common Stock, shares of such stock or other
securities as the holders of shares of Common Stock received pursuant to the
terms of such transaction; or (b) all outstanding Options may be cancelled by
the Board or the Committee as of a date prior to the effective date of any such
transaction and all payroll deductions shall be paid out to the participating
employees; or (c) all outstanding Options may be cancelled by the Board or the
Committee as of the effective date of any such transaction, provided that notice
of such cancellation shall be given to each holder of an Option, and each holder
of an Option shall have the right to exercise such Option in full based on
payroll deductions then credited to his account as of a date determined by the
Board or the Committee, which date shall not be less than ten (10) days
preceding the effective date of such transaction.

      17.   AMENDMENT OF THE PLAN. The Board may at any time, and from time to
time, amend this Plan in any respect, except that (a) if the approval of any
such amendment by the shareholders of the Company is required by Section 423 of
the Code, such amendment shall not be effected without such approval, and (b) in
no event may any amendment be made which would cause the Plan to fail to comply
with Section 423 of the Code.

      18.   INSUFFICIENT SHARES. In the event that the total number of shares of
Common Stock specified in elections to be purchased under any Offering plus the
number of shares purchased under previous Offerings under this Plan exceeds the
maximum number of shares issuable under this Plan, the Board or the Committee
will allot the shares then available on a pro rata basis.

      19.   TERMINATION OF THE PLAN. This Plan may be terminated at any time by
the Board. Upon termination of this Plan all amounts in the accounts of
participating employees shall be promptly refunded.

      20.   GOVERNMENTAL REGULATIONS. The Company's obligation to sell and
deliver Common Stock under this Plan is subject to listing on a national stock
exchange or quotation on the Nasdaq National Market (to the extent the Common
Stock is then so listed or quoted) and the approval of all governmental
authorities required in connection with the authorization, issuance or sale of
such stock.

      21.   GOVERNING LAW. The Plan shall be governed by Delaware law except to
the extent that such law is preempted by federal law.

                                      -5-

<PAGE>   6

      22.   ISSUANCE OF SHARES. Shares may be issued upon exercise of an Option
from authorized but unissued Common Stock, from shares held in the treasury of
the Company, or from any other proper source.

      23.   NOTIFICATION UPON SALE OF SHARES. Each employee agrees, by entering
the Plan, to promptly give the Company notice of any disposition of shares
purchased under the Plan where such disposition occurs within two years after
the date of grant of the Option pursuant to which such shares were purchased.

      24.   SPECIAL PROVISIONS FOR FIRST PLAN PERIOD. The following provisions
of this Section 24 shall apply with respect to the First Plan Period
notwithstanding any provision of the Plan to the contrary:

            (a)   Every eligible employee shall automatically become a
participant in the Plan for the First Plan Period at the highest percentage of
Compensation permitted under Section 5. No payroll deductions shall be required
for the First Plan Period; however, a participant may, at any time after the
effectiveness of the Plan's Registration Statement on Form S-8, elect to have
payroll deductions up to the aggregate amount which would have been credited to
his or her account if a deduction of ten percent (10%) of the Compensation which
he or she received on each pay day during the First Plan Period had been made
(the "Maximum Amount") or decline to participate by filing an appropriate
subscription agreement.

            (b)   Upon the automatic exercise of a participant's option on the
Exercise Date for the First Plan Period, a participant shall be permitted to
purchase shares with (i) the accumulated payroll deductions in his or her
account, if any, (ii) a direct payment from the participant, or (iii) a
combination thereof; provided, however that the total amount applied to the
purchase may not exceed the Maximum Amount.

                                      -6-

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00019-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00019-of-00352.parquet"}]]