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                                                                   EXHIBIT 10.33



                             SECURED PROMISSORY NOTE


$__________________                                             __________, 200_


     FOR VALUE RECEIVED, ______________ (the "Maker"), promises to pay to
Unisphere Networks, Inc., a Delaware corporation (the "Company"), or order, at
its principal executive offices, the principal sum of ______________ Dollars
($__________), together with interest on the unpaid principal balance of this
Note from time to time outstanding at the rate of ____% per annum, compounded
annually, until paid in full. Principal on this Note shall be paid in full on
January 1, 2003.

     Accrued interest shall be paid by the undersigned semi-annually on July 1
and January 1 of each year, commencing on July 1, 2001. Interest on this Note
shall be computed on the basis of a year of 365 days for the actual number of
days elapsed.

     Notwithstanding the foregoing, payment of this Note shall be required in
full, together with interest on the unpaid principal balance hereof at the rate
of ____% per annum, upon the date of the Maker's termination of employment with
the Company, regardless of whether such termination is voluntary or involuntary,
with or without cause or reason, if such termination of employment occurs prior
to December 1, 2002.

     Payment of this Note is secured by a security interest in shares of Common
Stock of the Company acquired by the Maker with the proceeds of the Note,
pursuant to a pledge agreement of even date herewith between the Maker and the
Company (the "Pledge Agreement").

     The Company shall have (i) full recourse against the Pledged Collateral
under the Pledge Agreement in connection with the repayment of the principal of
the Note and accrued interest thereon, (ii) recourse up to the Recourse Amount
(as hereinafter defined) against any other personal assets of the Maker and
(iii) recourse up to the Recourse Amount against any compensation or other
amounts due the Maker resulting from his/her employment by the Company, and a
right to immediate set off against such compensation or other amounts to the
full extent permitted by law. The Recourse Amount as of any time shall mean the
sum of (i) 100% of the principal amount hereof and (ii) the full amount of
accrued interest under this Note.

     The Maker may prepay on the 1st calendar day (or if banks in the State of
New York or the Commonwealth of Massachusetts are authorized by law to remain
closed, then on the next day such banks shall be open for business) of
September, December, March and June of each calendar year, in whole or in part,
without premium or penalty, any of the principal balance hereof or accrued
interest thereon; provided that such prepayment is at least equal to 25% of the
outstanding Principal due under this Note.

     This Note shall become immediately due and payable without notice or demand
upon the
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occurrence at any time of any of the following events of default (individually,
"an Event of Default" and collectively, "Events of Default"):

     1.   default in the payment when due of any principal or interest under
          this Note;

     2.   the occurrence of any Event of Default under the Pledge Agreement;

     3.   the institution by or against the Maker of any proceedings under the
          United States Bankruptcy Code or any other federal or state
          bankruptcy, reorganization, receivership, insolvency or other similar
          law affecting the rights of creditors generally or the making by the
          Maker of a composition or an assignment or trust mortgage for the
          benefit of creditors; or

     4.   the Maker violates the non-competition or confidentiality provisions
          of any employment contract, confidentiality and nondisclosure
          agreement or other agreement between the Maker and the Company.

     Upon the occurrence of an Event of Default, the holder shall have then, or
at any time thereafter, all of the rights and remedies afforded a secured
creditor by the Uniform Commercial Code as from time to time in effect in the
Commonwealth of Massachusetts or afforded by other applicable law.

     Maker agrees to pay on demand all costs of collection, including, but not
limited to, reasonable attorney's fees, incurred by the holder in connection
with any action taken to enforce the terms of this Note.

     No delay or omission on the part of the holder in exercising any right
under this Note or the Pledge Agreement shall operate as a waiver of such right
or of any other right of such holder, nor shall any delay, omission or waiver on
any one occasion be deemed a bar to or waiver of the same or any other right on
any future occasion. The Maker regardless of the time, order or place of signing
waives presentment, demand, protest and notices of every kind.

     If any amounts under this Note become due and payable on a Saturday or
Sunday or a day on which banks in the State of New York or the Commonwealth of
Massachusetts are authorized by law to remain closed, such amounts shall be paid
on the next succeeding day that such banks shall be open for business.

     Payments of principal and interest shall be made to the holder hereof, or
its designee, in such coin or currency of the United States of America as at the
time of payment shall be legal tender for the payment of public and private
debts, at the offices of Unisphere Networks, Inc., One Executive Drive,
Chelmsford, Massachusetts 01824.

     All rights and obligations hereunder shall be governed by the laws of the
Commonwealth of Massachusetts and this Note is executed as an instrument under
seal. The Maker hereby submits to the jurisdiction of the United States District
Court for the District of Massachusetts and of any Massachusetts state court,
with respect to any action, suit or proceeding brought

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against it arising out of or relating to this Note and the transactions
contemplated hereby. The Maker hereby irrevocably waives, to the fullest extent
permitted by applicable law, any objection which it may now or hereafter have to
the laying of the venue of any such action, suit or proceeding brought in such a
court and any claim that any such action, suit or proceeding brought in such a
court has been brought in an inconvenient forum.



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                                              Signature

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                                              Print Name







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