Exhibit
10.21





SEPARATION
AGREEMENT AND RELEASE





This
Separation Agreement and Release (the "Agreement") is by and between TranSwitch
Corporation, a Delaware corporation with its principal offices at 3 Enterprise
Drive, Shelton, Connecticut (the “Company”) and Dr. Santanu Das.




This
Agreement confirms the termination of your employment with TranSwitch
Corporation and the termination of the Executive Agreement (the “1997 Executive
Agreement”) and the Agreement for Severance (the “1997 Severance Agreement”),
each dated September 12, 1997, and each between you and the Company, all
effective onDecember 1, 2009 (the
"Separation Date").  The termination of your employment is by mutual
written consent.




As of the
Separation Date, you shall cease to serve as the President and Chief Executive
Officer of the Company and as an officer of any of the Company’s
subsidiaries.  You shall take such further action as shall be
reasonably requested by the Company to give effect to the
foregoing.




You shall
resign from the Board of Directors of the Company on January 31, 2010 or such
later date as shall be mutually agreed upon by you and the Company, provided in
each case that so long as you shall remain on the Board of Directors of the
Company, you shall be entitled to the benefits of the Indemnification Agreement,
dated April 3, 2009, between the Company and you, any provisions of the
Certificate of Incorporation or By-laws of the Company providing for
indemnification of directors and any insurance maintained by the Company for
purposes of providing indemnification of directors.  You shall not
receive any compensation for serving on the Board of Directors.




1.           Payments; Benefits; Equity
Incentives if this Agreement is signed.




In
consideration of your agreement, without revocation, to the terms and conditions
of this Agreement, and the release of claims as set forth below, the Company
will provide you the following payments, benefits and equity
incentives.  All payments by the Company described in this Agreement
will be subject to applicable tax withholding.




(a)         Separation
Pay.  You will receive a lump sum separation payment of
$350,000, payable on the first payroll date after the Separation Date, but in no
event later than December 31, 2009.  You agree not to receive any
compensation for accrued but unused vacation days.




(b)           Benefits.




(i)           Medical and
Dental.  The Company will pay or reimburse you for the payment
of medical and dental coverage for you and your spouse through end of the
“applicable continuation period” (as defined below).  The total amount
of the payment or reimbursement for your and your spouse’s continuing coverage
during the applicable continuation period  will be limited to the
amount of the COBRA premium that the Company could charge you for
employee-plus-spouse COBRA coverage, regardless of whether you or your spouse
are otherwise eligible for or elect to receive COBRA coverage under the
Company’s group health plan or elect to receive coverage outside of the
Company’s group health plan.  For the purposes hereof, the “applicable
continuation period” for you is the 24-month period beginning on the day next
following the date your Company group health plan coverage would otherwise
terminate by reason of the termination of your employment (which date is the
last day of the month in which your employment terminates); and the “applicable
continuation period” for your spouse will begin on the same date as your
applicable continuation period and will end on March 31,
2012.  Specific information regarding continuation of your medical and
dental benefits has been sent to you under separate cover and the Company will
continue to provide you with information necessary for you to continue such
benefits.


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(ii)           Life and Disability
Insurance.  The Company will reimburse your out of pocket
premium costs for a period of 24 months following the Separation Date for life
insurance and long-term disability insurance and, if available, short-term
disability insurance, in each case at coverage levels comparable to those in
effect as of the Separation Date, provided that if any such insurance is not
available, the Company will pay you, on an annual basis, an amount equal to the
cost of such insurance previously provided to you.




(iii)           401(k)
plan.  Your right to make additional contributions to the
Company’s 401(k) plan shall end as of the Separation Date.  You will
retain your rights to any accrued benefits under the 401(k) plan and any other
employee benefit plan in which you are a participant.




(iv)           D&O
Insurance.  Nothing in this Agreement shall affect your
coverage under the Company's directors' and officers' liability insurance
policy.  You will continue to be covered by directors’ and officers’
liability insurance for any claims arising in connection with your employment
prior to the Separation Date or serving at any time as a director on behalf of
the Company or any of its subsidiaries or affiliates on the same basis and to
the same extent as any active executives and directors.




(v)           Indemnification.  Nothing
in this Agreement shall affect your coverage under the Indemnification Agreement
between you and the Company.




(c)           Equity
Incentives.  All of your unvested stock options will vest upon
the Separation Date.  Any stock options that you hold as of the
Separation Date (including any stock options that vest pursuant to the preceding
sentence) shall be exercisable through the term of the options or two years,
whichever is greater.




(d)           2009 Management Incentive
Plan.  You shall not be entitled to receive any other amounts
or incentives under the Company’s 2009 Management Incentive Plan or any other
Company Incentive Program.




(e)           No Other
Payments.  You specifically acknowledge that the payments,
benefits and incentives described in Section 1(a), Section 1(b)(i) and (ii) and
Section 1(c) above constitute consideration not otherwise owed or due to you but
for this Agreement, and that the payments are being provided to you in
consideration of your executing, and not revoking, this
Agreement.  You shall not be entitled to any other severance,
compensation, wages or other payments (including, without limitation, under the
Agreements) other than as set forth in this Agreement and any other agreement
entered into by the Company and you on or after the date
hereof.


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2.           Restrictions and Continuing
Obligations.




(a)           Confidentiality and
Nondisclosure of Information.  You acknowledge that the
confidential information of the Company constitutes a valuable, special and
unique asset of the Company as to which it has the right to retain and hereby
does retain all of its proprietary interests.  In recognition of this
fact, you agree that you will continue to comply with the provisions of the
agreement captioned “Assignment of Inventions Covenants Against Disclosure,
Solicitation, Competition, Violation of the US EEA and Misuse of Intellectual
Property”, dated June 10, 2004, previously entered into by you with the Company
(the “Assignment of Inventions and Other Covenants
Agreement”).  Nothing contained herein shall be deemed to limit your
obligation to continue to comply with the provisions of such
Agreement.




(b)           Covenant against
Competition.  You hereby agree that for a period ending on the
later of one (1) year from (i) the Separation Date and (ii) the termination of
any other agreement for the provision of services by you to the Company entered
into on or after the date hereof, you will not engage in any business,
employment or consultancy assignment in the U.S.A., its Territories or Canada,
in which you are required to aid in the design or development or marketing or
specification or sale or commercialization of any product similar to any product
that the Company designed or developed or marketed or specified or sold or
otherwise commercialized during your employment with the Company.  You
will be allowed to work in the same communications semiconductor industry as the
Company in a non-competitive situation upon prior approval of the Company’s
Board of Directors (which will not be withheld unreasonably).  Section
6 of the Assignment of Inventions and Other Covenants Agreement shall be of no
further force and effect.  Notwithstanding the foregoing, you will be
allowed to work on behalf of a venture capital fund, private equity fund or
other investment fund, whether as a partner, employee, officer, consultant or
otherwise, even if such a fund invests in a company in the same industry as the
Company, provided that your services on behalf of such fund do not include your
serving as an adviser or consultant to, or an officer, director or employee of,
any portfolio company in the same industry as the Company.




(c)           Covenant against
Solicitation.  You hereby agree that you will continue to
comply with the provisions of the Assignment of Inventions and Other Covenants
Agreement previously entered into by you with the Company regarding solicitation
of employees, former employees, customers, partners or investors of the
Company.




(d)           Cooperation.  You
agree to cooperate with the Company in any legal proceedings or with respect to
any regulatory matters relating to the period of your employment with the
Company, provided that any reasonable travel, room and board expenses which you
incur in rendering such cooperation will be reimbursed by the Company, and you
shall be reimbursed for your time spent in such cooperation at a reasonable rate
commensurate with your stature and other obligations, such rate to be determined
by mutual agreement, and provided further that your cooperation shall be at such
reasonable times and locations as are consistent with your other
commitments..


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(e)           No
Disparagement.  You agree that you will not publish or
communicate any Disparaging (as defined below) remarks, comments or statements
regarding the Company or any of its officers, directors or stockholders for any
reason whatsoever, and the Company agrees not to publish or communicate any
Disparaging remarks, comments or statements regarding you for any reason
whatsoever.  ”Disparaging” remarks, comments or statements are those
that impugn the character, honesty, integrity, morality, business acumen,
abilities or any aspect of the operations or business of the individual or
entity being disparaged, that adversely affect the reputation, image, or
goodwill of, or are designed to induce others not to do business with, the
individual or entity being disparaged.  Nothing in this paragraph
shall be construed to preclude truthful disclosures in response to lawful
process as required by applicable law, regulation, or order or the directive of
a court, government agency or regulatory organization.




(f)           Other
Restrictions.  The restrictions set forth in this Section 2
shall be in addition to any restrictions that you may be subject to pursuant to
the terms of the Assignment of Inventions and Other Covenants Agreement
previously entered into by you with the Company.  Except to the extent
that Section 6 of the Assignment of Inventions and Other Covenants Agreement is
modified by Section 2(b) hereof, nothing contained herein shall be deemed to
limit your obligation to continue to comply with the provisions of such
Agreements.




3.           Releases.




(a)           Release by
You.  You and your representatives, agents, estate, heirs,
successors and assigns, absolutely and unconditionally hereby release, remise
and discharge the Releasees (defined to include the Company and/or any of its
parents, subsidiaries or affiliates, predecessors, successors or assigns, and
its and their respective current and/or former partners, directors,
shareholders/stockholders, officers, employees, attorneys and/or agents, all
both individually and in their official capacities), from any and all actions or
causes of action, suits, claims, complaints, contracts, liabilities, agreements,
promises, contracts, torts, debts, damages, controversies, judgments, rights and
demands, whether existing or contingent, known or unknown, suspected or
unsuspected, which arise out of employment with, change in employment status
with, and/or separation of employment from, the Company (collectively,
“Claims”).




This release is intended by you to be
all encompassing and to act as a full and total release of any Claims, whether
specifically enumerated herein or not, that you may have or have had against the
Releasees arising from conduct occurring up to and through the date of this
Agreement, including, but not limited to, any claims arising from any federal,
state or local law, regulation or constitution dealing with either employment,
employment benefits or employment discrimination such as those laws or
regulations concerning discrimination on the basis of race, color, creed,
religion, age, sex, sex harassment, sexual orientation, national origin,
ancestry, genetic carrier status, handicap or disability, veteran status, any
military service or application for military service, or any other category
protected under federal or state law; any contract, whether oral or written,
express or implied; any tort, including but not limited to under the Age
Discrimination in Employment Act of 1967, as amended, Title VII of the Civil
Rights Act of 1964, as amended, the Employee Retirement Income Security Act, as
amended and any claim for equity, stock options or other benefits; or any other
statutory and/or common law claim.  This release does not extend to
any claims or affect any rights you may have (i) pursuant to this Agreement,
(ii) pursuant to any other agreement you enter into with the Company on or after
the date hereof or (iii) under and in accordance with the terms of any employee
benefit plans in which you participate.


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(b)           Release by the
Company.  In consideration of the benefits set forth herein,
and other good and valuable consideration that the Company agrees it would not
be entitled to without executing this Agreement, the Company, for itself and on
behalf of any of its parents, subsidiaries or affiliates, predecessors,
successors or assigns (collectively, “Affiliates”), hereby irrevocably and
unconditionally releases, acquits and forever discharges you from any and all
claims which the Company or any of its Affiliates had, now has or may have now
or in the future against you which are in any way connected with, or in any way
arise out of or relate to, any cause whatsoever, from the beginning of time
through the Separation Date, including, but not limited to, any and all matters
relating to or arising out of your employment with the Company or any Affiliate
and the cessation thereof.  Notwithstanding the foregoing, this
paragraph shall not extend to and will not release any claims that have arisen
or arise from (i) your fraudulent conduct, criminal conduct or intentional
violation of any material law, (ii) your breach of this Agreement or (iii) your
breach of any agreement you enter into with the Company on or after the date
hereof.




4.           No Pending
Claims.  You represent and warrant that no action, suit or
proceeding has been commenced against the Company Released Parties by you, or on
your behalf, as of the Separation Date.    The Company
represents and warrants that no action, suit or proceeding has been commenced
against you by the Company or on the Company's behalf as of Separation
Date.




5.           Non-Admission;
Inadmissibility.  This Agreement and the performance of the
actions required by this Agreement shall not constitute, or in any manner be
construed as, an admission by you or the Company that any action either party
took with respect to the other was wrongful, unlawful or in violation of any
local, state or federal act, statute or constitution or susceptible of
inflicting any damages or injury on the other.  The parties expressly
deny any such wrongdoing, violation or liability for any and all claims asserted
by the other.  This Agreement is entered into solely to resolve all
matters related to or arising out of your employment with the Company and the
cessation thereof.  Neither this Agreement nor the fact of its
execution may be used as evidence in any action or proceeding of any nature by
anyone for any purpose except to enforce its terms..




6.           Entire
Agreement.  It is mutually understood and agreed that this
Agreement constitutes the entire understanding between you and the Company
relating to the subject matter of this Agreement and supersede any and all prior
agreements or understandings between you and the Company arising out of or
relating to your employment with the Company and the cessation thereof;
provided, that, nothing contained herein shall be construed to amend or modify
the Assignment of Inventions and Other Covenants Agreement.




7.           Choice of Law;
Venue.  The laws of the state of Connecticut shall govern the
validity of this Agreement, the construction of its terms and the interpretation
of the rights and duties of the parties hereto.  For purposes of any
actions or proceedings related to this Agreement or your employment with the
Company, the parties agree to submit to the exclusive jurisdiction of the state
and federal courts of the State of Connecticut.


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8.           Arbitration.  Any
dispute, controversy or claim between the parties arising out of the
interpretation or enforcement of this Agreement or the rights of any party
hereunder shall be submitted for resolution to the American Arbitration
Association (the “AAA”) pursuant to the AAA’s then existing Employment
Arbitration Rules.




9.           Changes or
Modifications.  This Agreement may not be changed or modified
except by a writing signed by both you and an authorized representative of the
Company.  The failure of a party to insist upon strict adherence to
any term of this Agreement on any occasion shall not be considered a waiver
thereof or deprive that party of the right thereafter to insist upon strict
adherence to that term or any other term of this Agreement.




10.           Effective
Date.




(a)           This
Agreement is valid only if signed by you and returned to the Company within
twenty-two (22) days of the date you receive this Agreement.  You have
seven (7) days following the date you sign this Agreement during which to revoke
it, by delivering a written notice of revocation to Thomas Richtarich,
TranSwitch Corporation, 3 Enterprise Drive, Shelton, CT 06484.  To be
effective, such revocation must be received by Thomas Richtarich no later than
11:59 p.m. (Connecticut time) on the seventh (7th) calendar day following your
execution of this Agreement.  Provided that it is not revoked, this
Agreement will be effective on the eighth (8th) day following the Company's
receipt of the valid Agreement signed by you (the "Effective
Date").




(b)           You
acknowledge that the Company has provided you with at least twenty-one (21) days
from the date upon which this Agreement is delivered to you within which to
consider the terms and effect of this Agreement.  You agree that any
changes made to the Agreement from the time it was first offered to you, whether
material or immaterial, do not restart the running of the 21-day
period.  If you elect to execute this Agreement before the expiration
of the 21-day period, you acknowledge that you have chosen, of your own free
will without any duress, to waive your right to the full twenty-one (21)
days.




(c)           The
Company hereby advises you to consult with an attorney prior to signing this
Agreement.




11.           Acknowledgements.  By
signing this Agreement, you acknowledge that:




(a)           You
have read this Agreement;




(b)           You
understand and know that you are giving up important rights, including but not
limited to rights under the acts, statutes, codes, ordinances, rules and laws
set forth in Section 3(a) of this Agreement, and any other constitutional,
statutory common law rights and privileges;


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(c)           You
understand that as a result of entering into this Agreement you will not have
the right to assert that the Company unlawfully terminated your employment or
violated any rights in connection with your employment;




(d)           Except
as set forth herein, no promises or inducements for this Agreement have been
made, and you are entering into this Agreement without reliance upon any
statement or representation by any of the Company Released Parties or any other
person concerning any fact material hereto;




(e)           You
are signing this Agreement knowingly, voluntarily, and free of any
duress.




12.           Section
Headings.  Section headings contained in this Agreement have
been inserted for convenience of reference only, are not to be considered a part
of this Agreement and shall not affect the interpretation of any provision
hereof.




13.           Severability.  It
is the intent of the parties that the provisions of this Agreement be enforced
to the fullest extent permitted by law.  In case any provision of this
Agreement shall be declared by an arbitrator or a court of competent
jurisdiction to be invalid, illegal or unenforceable as written, the parties
agree that the court shall modify and reform such provision to permit
enforcement to the greatest extent permitted by law.  In addition, if
any provision of this Agreement shall be declared invalid, illegal or
unenforceable, the validity, legality and enforceability of the remaining
provisions of this Agreement shall in no way be affected or impaired
thereby.




14.           Counterparts.  This
Agreement may be executed in counterparts.




If this
Agreement is acceptable to you, please sign it and return it to Thomas
Richtarichwithin
time frame specified in Section 10(a).




Sincerely
      yours,/s/ Robert A. BosiRobert
      A. BosiVice
      President and Chief Financial Officer, TranSwitch
    CorporationAgreed
      and Accepted on this6th
      day of November, 2009
            
            Witnessed/s/ Dr. Santanu Das
            
            /s/
      Thomas P. RichtarichDr.
      Santanu Das
            
            Print
      Name:


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