Exhibit 10.2

SEVERANCE PAY AGREEMENT

This agreement is entered into by and between Avici Systems Inc. (the “Company”)
and William J. Stuart (“you”) effective as of August 28, 2006.

SEVERANCE PAY

You will receive severance pay if you are terminated from employment with the
Company without Cause or if you resign for Good Reason.

The amount of the severance pay will be twelve (12) months of your base salary
at the rate in effect on your separation date, less applicable taxes. In
addition, you will continue to be eligible to participate in the Company’s group
health, dental, and vision insurance plans, and, to the fullest extent permitted
by the plans and applicable law, the Company’s 401k plan and the Company-paid
life insurance plan, at the levels in effect on your separation date, for up to
twelve (12) months. During this continuation period, the Company will pay the
same percentage of your monthly group health, dental, vision, and life insurance
premiums that it pays for active employees. At the end of the twelve (12) month
period, you will, to the fullest extent permitted by the plans and applicable
law, be eligible to continue your group health, dental, and vision coverage for
up to an additional eighteen (18) months under COBRA. If you elect COBRA
coverage you will be solely responsible for the full premium amounts.

To receive severance pay, you will be required to sign a release of claims in a
form reasonably acceptable to the Company. Severance pay will be paid in
accordance with the Company’s regular payroll practices beginning promptly after
your signed release of claims goes into effect.

STOCK OPTIONS

If you are terminated without Cause prior to a Change of Control, the vesting of
your remaining unvested Company options will accelerate by six (6) months.

In the event of a Change of Control, you will receive accelerated vesting on 50%
of your remaining unvested options.

If, in connection with or following a Change of Control, you are terminated
without Cause or you resign for Good Reason, the vesting on all of your
remaining unvested options will be accelerated such that 100% of your options
will become fully vested.

DEFINITIONS; OTHER

A termination for “Cause” as used herein means your being terminated by the
Company due to (a) willful misconduct or violation of Company policy which
causes material harm to the Company, (b) willful breach of an employment or
other agreement with the Company which causes material harm to the Company, or
(c) being convicted of any felony.

A resignation for “Good Reason” as used herein means you resign because,
following or at the time of a Change of Control, (a) you are transferred to a
lesser position or suffer a material reduction in responsibility; (b) your
compensation is decreased; (c) you are required to relocate

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more than fifty (50) miles from your work location immediately prior to the
Change of Control; or (d) you are excluded from any material compensatory or
benefit plan or arrangement made available to similarly situated employees of
the acquiring party.

“Change of Control” as used herein means the closing of (a) the sale of the
Company by merger, consolidation or purchase of outstanding capital stock in
which the shareholders of the Company, as such, no longer own a majority of the
outstanding equity securities of the Company or its successor; (b) any sale of
all or substantially all of the assets of the Company, other than in a spin-off
or similar transaction; or (c) any other acquisition or disposition of the
business or assets of the Company, as determined by the Board.

Assignment. This agreement will be binding on and inure to the benefit of the
parties and the Company’s successors and assigns.

Employment at Will. This agreement is not an employment contract. Nothing in
this agreement modifies your status as an employee at will or guarantees
employment for any length of time.

Entire Agreement; Modification; Governing Law. Except as otherwise provided
herein, this agreement constitutes the only agreement between you and the
Company with respect to the subject matter hereof, superseding in all respects
any and all prior oral or written agreements or understandings pertaining to the
subject matter hereof. This agreement may be amended or modified only in a
writing signed by both you and the Company. Any dispute concerning this
agreement will be governed by the internal laws of Massachusetts.

 

AVICI SYSTEMS INC., by:

               WILLIAM J. STUART

 

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