Exhibit 4.1


2002 MASTER AGREEMENT
  MORGAN STANLEYCAPITAL SERVICES INC.
    
    
    
    MITEL US HOLDINGS, INC.
 
  1. Interpretation
 Definitions.
 Inconsistency.
 Single Agreement.
 2. Obligations
 General Conditions.




---



##### 



Change of Account.
 Netting of Payments.
     Deduction or Withholding for Tax.
 Gross-Up.
    ISDA® 2002
 2




---



##### 



Liability.
     3. Representations
  Basic Representations.
 Status.
 Powers.
 ISDA® 2002
 3




---



##### 



No Violation or Conflict.
 Consents.
 Obligations Binding.
 Absence of Certain Events.
 Absence of Litigation.
 Accuracy of Specified Information.
 Payer Tax Representation.
 Payee Tax Representations.
 No Agency.
 4. Agreements
  Furnish Specified Information.
   ISDA® 2002
 4




---



##### 



Maintain Authorizations.
 Comply With Laws.
 Tax Agreement.
 Payment of Stamp Tax.
 5. Events of Default and Termination Events
 Events of Default
 Failure to Pay or Deliver.
 Breach of Agreement; Repudiation of Agreement.
   ISDA® 2002
 5




---



##### 



Credit Support Default.
    Misrepresentation.
 Default Under Specified Transaction.
     ISDA® 2002
 6




---



##### 



Cross-Default.
   Bankruptcy.
  ISDA® 2002
 7




---



##### 



Merger Without Assumption.
   Termination Events.
 Illegality.
   Force Majeure Event.
 (1)
    
    the Office through which such party (which will be the Affected Party) makes and
receives payments or deliveries with respect to such Transaction is prevented from
performing any absolute or contingent obligation to make a payment or delivery in
respect of such Transaction, from receiving a payment or delivery in respect of
such Transaction or from complying with any other material provision of this
Agreement relating to such Transaction (or would be so prevented if such payment,
delivery or compliance were required on that day), or it becomes impossible or
impracticable for such Office so to perform, receive
 ISDA ® 2002
 8




---



##### 



or comply (or it would be impossible or impracticable for such Office so to perform,
receive or comply if such payment, delivery or compliance were required on that day); or(2)
    
    such party or any Credit Support Provider of such party (which will be the Affected Party) is
prevented from performing any absolute or contingent obligation to make a payment or
delivery which such party or Credit Support Provider has under any Credit Support Document
relating to such Transaction, from receiving a payment or delivery under such Credit
Support Document or from complying with any other material provision of such Credit
Support Document (or would be so prevented if such payment, delivery or compliance were
required on that day), or it becomes impossible or impracticable for such party or Credit
Support Provider so to perform, receive or comply (or it would be impossible or
impracticable for such party or Credit Support Provider so to perform, receive or comply
if such payment, delivery or compliance were required on that day),
  Tax Event.
 Tax Event Upon Merger.
 Credit Event Upon Merger.
  ISDA® 2002
 9




---



##### 



Additional Termination Event.
 Hierarchy of Events.
    Deferral of Payments and Deliveries During Waiting Period.
   Inability of Head or Home Office to Perform Obligations of Branch.
 ISDA® 2002
 10




---



##### 



6. Early Termination; Close-Out Netting
 Right to Terminate Following Event of Default.
 Right to Terminate Following Termination Event.
 Notice.
 Transfer to Avoid Termination Event.
   Two Affected Parties.
 ISDA® 2002
 11




---



##### 



Right to Terminate.
        Effect of Designation.
   ISDA® 2002
 12




---



##### 



Calculations; Payment Date.
 Statement .
 Payment Date .
 Payments on Early Termination .
 Events of Default .
 Termination Events .
 One Affected Parry .
 Two Affected Parties .
 ISDA® 2002
 13




---



##### 



Mid-Market Events .
   Adjustment for Bankruptcy .
 Adjustment for Illegality or Force Majeure Event .
 Pre-Estimate .
 Set-Off .
  ISDA®
2002
 14




---



##### 



7. Transfer
     8. Contractual Currency
 Payment in the Contractual Currency .
 Judgments .
 ISDA® 2002
 15




---



##### 



Separate Indemnities .
 Evidence of Loss .
 9. Miscellaneous
 Entire Agreement .
 Amendments .
 Survival of Obligations .
 Remedies Cumulative .
 Counterparts and Confirmations .
  
 No Waiver of Rights .
 Headings .
 ISDA® 2002
 16




---



##### 



Interest and Compensation.
 Prior to Early Termination
 Interest on Defaulted Payments .
 Compensation for Defaulted Deliveries .
 Interest on Deferred Payments .
    ISDA® 2002
 17




---



##### 



Compensation for Deferred Deliveries.
     Early Termination .
 Unpaid Amounts.
 Interest on Early Termination Amounts.
 Interest Calculation .
 ISDA® 2002
 18




---



##### 



10. Offices; Multibranch Parties
    11. Expenses
  12. Notices
 Effectiveness .
      ISDA®2002
 19




---



##### 



Change of Details .
 13. Governing Law and Jurisdiction
 Governing Law .
 Jurisdiction .
      Service of Process .
 Waiver of Immunities .
 ISDA® 2002
 20




---



##### 



14. Definitions
  Additional Representation 
 Additional Termination Event
 Affected Party
 Affected Transactions
 Affiliate
 Agreement has
 Applicable Close-out Rate
           ISDA® 2002
 21




---



##### 



 Applicable Deferral Rate 
    Automatic Early Termination
 Burdened Party
 Change in Tax Law
 Close-out Amount
 ISDA® 2002
 22




---



##### 



ISDA® 2002
 23




---



##### 



Confirmation
 consent
 Contractual Currency
 Convention Court
 Credit Event Upon Merger
 Credit Support Document
 Credit Support Provider
 Cross-Default
 Default Rate
 Defaulting Party
 Designated Event
 Determining Party
 Early Termination Amount
 Early Termination Date
 electronic messages electronic messaging system 
 English law English
 Event of Default
 Force Majeure Event
 General Business Day
 Illegality
 ISDA®  2002
 24




---



##### 



Indemnifiable Tax
 law unlawful
 Local Business Day
 Local Delivery Day
 Master
Agreement
 Merger Without Assumption
 Multiple Transaction Payment Netting
 Non-affected Party
 Non-default Rate
 Non-defaulting Party
 Office
 Other Amounts
 ISDA® 2002
 25




---



##### 



Payee
 Payer
 Potential Event of Default
 Proceedings
 Process Agent
 rate of exchange
 Relevant Jurisdiction
 Schedule
 Scheduled Settlement Date
 Specified Entity
 Specified Indebtedness
 Specified Transaction
 Stamp Tax
 Stamp Tax Jurisdiction
 ISDA® 2002
 26




---



##### 



Tax
 Tax Event
 Tax Event Upon Merger
 Terminated Transactions
 Termination Currency
 Termination Currency Equivalent
 Termination Event
 Termination Rate
 Threshold Amount
 Transaction
 Unpaid Amounts
 ISDA® 2002
 27




---



##### 



Waiting Period
    MORGAN STANLEY CAPITAL SERVICES INC.
    
    MITEL US HOLDINGS, INC.By:
    
    /s/ Steven T. Naftzger

Name: Steven T. Naftzger
    
    
    
    By:
    
    /s/ Greg Hiscock

Name: Greg HiscockTitle: Authorized Signator
    
    
    
    
    
    Title: Secretary/TreasurerDate: Nov 27 2007
    
    
    
    
    
    Date: Dec 12/07
 28




---



##### 



Execution
Copy
 SCHEDULE   2002 MASTER AGREEMENT
   MORGAN STANLEY CAPITAL SERVICES INC.
a Delaware corporation
  MITEL US HOLDINGS, INC.
a Delaware corporation
 Part 1. Termination Provisions.
 (a)
    
    Specified Entity means in relation to Party A for the purpose of:Section 5(a)(v) (Default Under Specified Transaction)
    
    AffiliatesSection 5(a)(vi) (Cross Default)
    
    None SpecifiedSection 5(a)(vii) (Bankruptcy)
    
    None SpecifiedSection 5(b)(v) (Credit Event Upon Merger)
    
    None Specifiedand in relation to Party B for the purpose of:Section 5(a)(v) (Default Under Specified Transaction)
    
    AffiliatesSection 5(a)(vi) (Cross Default)
    
    None SpecifiedSection 5(a)(vii) (Bankruptcy)
    
    None SpecifiedSection 5(b)(v) (Credit Event upon Merger)
    
    None Specified
 Specified Transaction
 29




---



##### 



Execution Copy
 (c)
    
    Cross Defaultapplies to Party A and Party B.Specified Indebtednesshas the meaning specified in Section 14 of this Agreement. In
addition, with respect to Party B, Specified Indebtedness shall include, without
limitation, the obligations of Party B under that certain Credit Agreement dated as of
August 16, 2007, made by and between Party B, Mitel Networks Corporation., Mitel Networks,
Inc., Arsenal Acquisition Corporation, Morgan Stanley Senior Funding, Inc., as U.S.
Administrative Agent, Morgan Stanley & Co. Incorporated, as Collateral Agent, Morgan
Stanley Senior Funding (Nova Scotia) Co. as Canadian Administrative Agent, Morgan Stanley
Senior Funding, Inc., Morgan Stanley Senior Funding (Nova Scotia) Co, and Merrill Lynch,
Pierce, Fenner & Smith Incorporated, as Syndication Agents and Arrangers, and the other
Lenders party thereto, as the same may be amended, modified, supplemented or replaced from
time to time (the Credit Agreement) (and to which other lenders, borrowers or other
persons may be or become party).Threshold Amountmeans, with respect to a party, an amount equal to USD 20,000,000 (or
the equivalent in another currency, currency unit or combination thereof as reasonably
determined by the other party as of that date).
 (d)
    
    Bankruptcy.Section 5(a)(vii) is hereby amended by replacing the number 15 with the
number 30 in lines 15 and 23 thereof.(e)
    
    Credit Event Upon Mergerapplies to Party A and Party B.(f)
    
    The Automatic Early Terminationprovision of Section 6(a) of this Agreement will not apply
to Party A and will not apply to Party B.(g)
    
    Termination Currencymeans United States Dollars (USD).(h)
    
    Additional Termination Eventswill apply. The following will constitute an
Additional Termination Event, where Party B shall be the Affected Party and all Transactions
shall be Affected Transactions:If (A) Party A is no longer (x) a Secured Party (as defined below) with rights to
share on a pro rata and pari passu basis with the Lenders, in connection with the
Lenders right to receive payments of principal under the Credit Agreement, in the
proceeds of the collection or sale of any Collateral (as defined below) or (y) a
beneficiary under any guaranty issued for the benefit of the Secured Parties, in
each case as a result of actions taken without Party As consent; provided, however,
that the foregoing shall not constitute an Additional Termination Event if,
contemporaneously with any such events, Party B shall have executed an ISDA Credit
Support Annex or arranged for other credit support, in either case for the benefit
of Party A and on terms and conditions reasonably satisfactory to Party A.The following terms shall have the meanings set forth below for purposes of this clause
(G):
      30




---



##### 



Execution Copy
 Part 2. Representations.
 (a)
    
    Party A and Party B Payer Tax Representations. For the purpose of Section 3(e) of this
Agreement, each of Party A and Party B makes the following representation:It is not required by any applicable law, as modified by the practice of any relevant
governmental revenue authority, of any Relevant Jurisdiction to make any deduction or
withholding for or on account of any Tax from any payment (other than interest under
Section 9(h) of this Agreement) to be made by it to the other party under this
Agreement. In making this representation, it may rely on: (i) the accuracy of any
representations made by the other party pursuant to Section 3(f) of this Agreement;
(ii) the satisfaction of the agreement contained in Sections 4(a)(i) or 4(a)(iii) of
this Agreement and the accuracy and effectiveness of any document provided by the other
party pursuant to Sections 4(a)(i) or 4(a)(iii) of this Agreement; and (iii) the
satisfaction of the agreement of the other party contained in Section 4(d) of this
Agreement, except that it will not be a breach of this representation where reliance is
placed on clause (ii) and the other party does not deliver a form or document under
Section 4(a)(iii) of this Agreement by reason of material prejudice to its legal or
commercial position.
 (b)
    
    Party A and Party B Payee Tax Representations.(i)
    
    For the purpose of Section 3(f) of this Agreement, Party A makes the
following representation: it is a U.S. corporation duly organized and incorporated under the
laws of the State of Delaware (and is therefore a US Person as such term is used in
Section 1.1441-4(a)(3)(ii) of the United States Treasury Regulations) and is an exempt
recipient under Section 1.6049-4(c)(l)(ii) of the United States Treasury Regulations.(ii)
    
    For the purpose of Section 3(f) of this Agreement, Party B makes the following
representation: it is a U.S. corporation duly organized and incorporated under the
laws of the State of Delaware (and is therefore a US Person as such term is used in
Section 1.1441-4(a)(3)(ii) of the United States Treasury Regulations) and is an exempt
recipient under Section 1.6049-4(c)(l)(ii) of the United States Treasury Regulations.
 Part 3. Agreement to Deliver Documents.
  (a)
    
    Tax forms, documents or certificates to be delivered are:
 Party requiredto deliverdocument
    
    Form/Document/Certificate
    
    Date by which to be deliveredParty A and
Party B
    
    An original
executed United
States Internal Revenue
Service Form W-9 (or any
successor thereto) with
respect to any payments
received or to be
received by Party A or
Party B, as the case may
be, that are not
effectively connected
or otherwise
attributable to such
Partys conduct of a
trade or business in the
United States.
    
    (i) Upon the execution of
this Agreement; (ii)promptly upon reasonable
demand by Party A or Party
B, as applicable; and (iii)
promptly upon any Form W-9
(or any successor thereto)
previously provided by Party
B becoming obsolete,
incorrect, or expired.
 31




---



##### 



Execution Copy
  Covered byParty required to
    
    
    
    
    
    Section 3(d)Deliver document
    
    Form/Document/Certificate
    
    Date by which to be delivered
    
    RepresentationParty A and Party B
    
    Either (i) asignature booklet
    
    Upon execution of this
    
    Yescontainingasecretarys
    
    Agreementandasdeemedcertificateandresolutions
    
    necessaryforanyfurther(authorizing resolutions) or (ii)
    
    documentation.otherauthoritydocumentation,ineithercase,which(x)authorizes the party to enter intoderivativestransactionsof thetype contemplated by the partiesand (y) is reasonably satisfactoryin form and substance to theother party.Party A and Party B
    
    Certified copies of documents
    
    As soon as practicable after the
    
    Yesevidencing each partys capacity
    
    execution of this Agreement,to execute this Agreement, each
    
    and,withrespecttoaConfirmation and any Credit
    
    Confirmation, upon the otherSupport Document (if applicable)
    
    partys request.and to perform its obligationshereunder and thereunder.Party A and Party B
    
    A copy of the annual report of
    
    As soon as practicable after the
    
    Yessuch party (in the case of Party
    
    execution of this Agreement andA, in respect of Morgan Stanley)
    
    also within 120 calendar dayscontaining audited consolidated
    
    after the end of each fiscal yearfinancial statements for each such
    
    while there are any obligationsfiscalyear,certifiedby
    
    outstandingunderthisindependentcertifiedpublic
    
    Agreement.accountantsandpreparedinaccordancewithgenerallyaccepted accounting principles inthe country in which such partyis organized.Party A
    
    A duly executed copy of the
    
    As soon as practicable after the
    
    NoCreditSupportDocument
    
    execution of this Agreement.specified in Part 4 of thisSchedule.Party B
    
    Written noticeprior to the
    
    At least 15 days prior to such
    
    Yesprepayment in full of the Loans
    
    prepayment or releaseor release of any Collateral(other than with respect to anyCollateral released pursuant toSection 7.2.11 of the CreditAgreement).
 32




---



##### 



Execution Copy
 Covered byParty required to
    
    
    
    
    
    Section 3(d)Deliver document
    
    Form/Document/Certificate
    
    Date by which to be delivered
    
    RepresentationParty A and Party B
    
    Such other documents as
    
    Upon request
    
    Nothe other party mayreasonably request.
 Part 4. Miscellaneous.
 (a)
    
    Addresses for Notices. For the purpose of Section 12(a) of
this Agreement:
 (i)
    
    Address for notices or communications to Party A:MORGAN STANLEY CAPITAL SERVICES INC.1585 BroadwayNew York, New York 10036-8293Attention: CHIEF LEGAL OFFICERTelephone No.: +1 212 761 4000Facsimile No: +1 212 507 4622United States taxpayer identification number: 13-3292567.(ii)
    
    Address for notices or communications to Party B:MITEL US HOLDINGS, INC.350 Legget DriveKanata, Ontario, K2K 2W7CanadaAttention: TREASURERTelephone No.: 613 592-2122Facsimile No.: 613 592-7838With a copy to:MITEL US HOLDINGS , INC350 Legget DriveKanata, Ontario, K2K 2W7CanadaAttention: LEGAL DEPARTMENTFacsimile No.: 613 592-7802Government / taxpayer identification number: 753249676
 33




---



##### 



Execution Copy
 (b)
    
    Process Agent. For the purpose of Section 13(c) of this Agreement:
 (i)
    
    Party A irrevocably appoints as its Process Agent:MORGAN STANLEY CAPITAL SERVICES INC.1585 BroadwayNew York, New York 10036-8293Attention: CHIEF LEGAL OFFICER(ii)
    
    Party B irrevocably appoints as its Process Agent:CT CORPORATION SYSTEM111 Eighth AvenueNew York, New York 10016:
 (c)
    
    Offices. The provisions of Section 10(a) of this Agreement will apply to Party A and to Party
B.(d)
    
    Multibranch Party. For the purpose of Section 10(c) of this Agreement:Party A is not a Multibranch Party.Party B is not a Multibranch Party.(e)
    
    Calculation Agent means Party A, unless
Party) A is in an Event of Default, in which case a
mutually acceptable third party dealer will be appointed by the parties hereto.(f)
    
    Credit Support Document means any credit support annex, and any other document, any of
which by its terms secures, guarantees or otherwise supports either partys obligations under
this Agreement, including, but not limited to, in the case of Party A, the guarantee of Morgan
Stanley ; and, in the case of Party B, the Collateral Documents and any agreement or
instrument as set forth in the Credit Agreement, now or hereafter existing, of any kind or
nature which secures, guarantees or otherwise provides direct or indirect assurance of payment
or performance of any existing or future obligation of Party B under this Agreement, made by
or on behalf of any person or entity (including, without limiting the generality of the
foregoing, any agreement or instrument granting any lien, security interest, assignment,
charge or encumbrance to secure any such obligation, any guaranty, suretyship, letter of
credit, put option or subordination agreement relating to any such obligation and any keep
well or other financial support agreement relating to Party B, including but not limited to
those certain Loan Documents (as such term is defined in the Credit Agreement) (collectively,
the Party B CSD).(g)
    
    Credit Support Provider means in relation to Party A: Morgan Stanley, a Delaware company.Credit Support Provider means in relation to Party B: Any party executing or delivering
any Parry BCSD.(h)
    
    Governing Law; Jurisdiction. Sections 13(a) and (b) of the Agreement shall be
deleted and replaced with the following:(a) Governing Law. This Agreement will be governed by and construed in accordance
with the laws of the State of New York.
 34




---



##### 



Execution Copy
 (b) Jurisdiction.
   (i)
    
    Waiver of Jury Trial. Each party waives, to the fullest extent permitted by applicable law,
any right it may have to a trial by jury in respect of any Proceedings relating to this
Agreement or any Credit Support Document.(j)
    
    Netting of Payments.Multiple Transaction Payment Netting will apply for the purpose of
Section 2(c) of this Agreement to all Transactions under this Agreement.(k)
    
    Affiliatehas the meaning specified in Section 14 of this Agreement, but excludes
Morgan Stanley Derivative Products Inc.(1)
    
    Absence of Litigation.For the purpose of Section 3(c) of this Agreement Specified
Entityshall mean Affiliates in relation to both parties.(m)
    
    No Agency. The provisions of Section 3(g) will apply to this Agreement.(n)
    
    Additional Representationwill apply. For the purpose of Section 3 of this
Agreement the following Section 3(h) will constitute an Additional Representation:(h)Relationship Between Parties.Each party will be deemed to represent to the other
party on the date on which it enters into a Transaction that (absent a written agreement
between the parties that expressly imposes affirmative obligations to the contrary for
that Transaction):
 Non-Reliance.
 Assessment and Understanding.
 Status of Parties.
 35




---



##### 



Execution Copy
 (o)
    
    Recording of Conversations.Each party (i) consents to the recording of telephone
conversations between the trading, marketing and other relevant personnel of the parties in
connection with this Agreement or any potential Transaction, (ii) agrees to obtain any
necessary consent of, and give any necessary notice of such recording to, its relevant
personnel and (iii) agrees, to the extent permitted by applicable law, that recordings may be
submitted in evidence in any Proceedings.
 Part 5. Other Provisions
 (a)
    
    Limitation on Condition Precedent:Section 2(a)(iii) of this Agreement is hereby amended by
adding the following phrase at the end of clause (1) immediately before the last comma of
such phrase:provided, however, that if an Event of Default or Potential Event of Default has occurred
and is continuing for longer than thirty (30) Local Business Days without an Early
Termination Event being designated, then the condition specified in this clause (1) will
cease to be a condition precedent to the obligations under Section 2(a)(i).(b)
    
    Additional Representations.In addition to the provisions addressed above in Part 4 of the
Schedule,
Section 3 of this Agreement is hereby amended by adding at the end thereof the following
sub-
paragraphs:
 Eligible Contract
Participant.
 Non-ERISA Representation.
 (c)
    
    Export of Defaults.The occurrence or designation of an Early Termination Date on account
of an
Event of Default or Termination Event with respect to a party hereto (X) (where X is the
Defaulting
Party or sole Affected Party) shall constitute a material breach and event of default
(howsoever
described) under all transactions, excluding the Collateral Documents, between X and the
other party
(Y) or any Affiliate of Y (whether or not arising under this Agreement, whether or not
matured,
whether or not contingent and regardless of the currency, place of payment or booking
office of the
obligation) (together, the Other Transactions), whereupon Y or any Affiliate of Y shall
have the
right to terminate, liquidate and otherwise close out any such Other Transactions (and X
shall be liable
for any damages suffered by Y and any Affiliate of Y as a result thereof).(d)
    
    Single Relationship.The parties and their Affiliates intend that all Transactions and all
other
obligations (whether or not arising under this Agreement, whether or not matured, whether
or not
contingent and regardless of the currency, place of payment or booking office of the
obligation) shall
be treated as mutual and part of a single, indivisible contractual and business
relationship.(e)
    
    Procedures for Entering Into Transactions.Party A will deliver to Party B a Confirmation
relating to
each Transaction.
 36




---



##### 



Execution Copy
 (f)
    
    Form of Agreement. The parties hereby agree that the text of the body of the Agreement is
intended
to be the printed form of 2002 ISDA Master Agreement as published and
copyrighted by the International Swaps and Derivatives Association,(g)
    
    Transfers. The following provision (c) is hereby added to Section 7 of this Agreement:
  (h)
    
    2002 Master Agreement Protocol. Party A is an adherent to the ISDA 2002 Master Agreement
Protocol published by the International Swaps and Derivatives
Association, Inc. on July 15,
2003 (the 2002 Protocol). In the event that Party B is not an adherent to the 2002
Protocol, Party A and Party B hereby agree that in accordance with the terms of the 2002
Protocol, certain amendments shall be deemed to be made to:(i) sets of definitions and provisions published before 2002 by ISDA (each an ISDA
Definitions Booklet); and(ii) documents containing credit support provisions published before 2002 by ISDA (each
called Credit Support Provisions);in each case in accordance with the terms of the 2002 Protocol as specified in Annexes 1-18
thereof. As used in this Agreement (including in all Confirmations related to it), any
reference to any ISDA Definitions Booklet and/or Credit Support Provisions shall mean that
ISDA Definitions Booklet and/or those Credit Support Provisions as deemed amended in
accordance with the terms of the 2002 Protocol.(i)
    
    Accuracy of Specified Information. Section 3(d) is
hereby amended by adding in the third line thereof after the word respect and before the period the words or, in the case of
audited or unaudited financial statements, present fairly in all material respects the
consolidated financial condition of the persons covered thereby as at the dates thereof and
the results of their operations for the periods then ended.(j)
    
    This agreement is entered into in connection with the First Lien Credit Agreement dated as of
August 16, 2007, made by and between Mitel Networks, Inc. Mitel Networks Corporation., Party B, ,
Arsenal Acquisition Corporation, Morgan Stanley Senior Funding, Inc., as U.S.
Administrative Agent, Morgan Stanley & Co. Incorporated, as Collateral Agent, Morgan
Stanley Senior Funding (Nova Scotia) Co. as Canadian Administrative Agent, Morgan Stanley
Senior Funding, Inc., Morgan Stanley Senior Funding (Nova Scotia) Co, and Merrill Lynch,
Pierce, Fenner & Smith Incorporated, as Syndication Agents and Joint Lead Arrangers, and
the other Lenders party thereto, as the same may be amended, modified, supplemented or
replaced from time to time (the First Lien Credit Agreement) (and to which other lenders,
borrowers or other persons may be or become party) and any Transaction entered into in this
Agreement constitutes a Rate Protection Agreement for purposes this Agreement. Capitalized
terms used but not defined in this Agreement shall have the meanings given to them in the
First Lien Credit Agreement.
 37




---



##### 



MASTER AGREEMENT
    
  
 Termination Provisions.
 (a)
    
    Specified Entity means
in relation to Party A for the purpose of:Section 5(a)(v) (Default Under Specified Transaction)
    
    AffiliatesSection 5(a)(vi) (Cross Default)
    
    None SpecifiedSection 5(a)(vii) (Bankruptcy)
    
    None SpecifiedSection 5(b)(v) (Credit Event Upon Merger)
    
    None Specifiedand in relation to Party B for the purpose of:Section 5(a)(v) (Default Under Specified Transaction)
    
    AffiliatesSection 5(a)(vi) (Cross Default)
    
    None SpecifiedSection 5(a)(vii) (Bankruptcy)
    
    None SpecifiedSection 5(b)(v) (Credit Event Upon Merger)
    
    None Specified(b)
    
    Specified
Transaction shall have the meaning specified in Section 14 of this Agreement
 29




---



##### 



IN WITNESS WHEREOF,
 MORGAN STANLEY CAPITAL SERVICES INC.
    
    MITEL US HOLDINGS, INC.By:
    
    
    
    By:
    
    /s/ Steve SpoonerName:
    
    Name:
    
    Steve SpoonerTitle:
    
    Title:
    
    PresidentDate:
    
    Date:
 38




---



##### 



Execution Copy
 IN WITNESS WHEREOF,
 MORGAN STANLEY CAPITAL SERVICES INC.
    
    MITEL US HOLDINGS, INC.By:
    
    /s/ Steven T. Naftzger
    
    By:Name: Steven T. Naftzger
    
    
    
    Name:Title: Authorized Signator
    
    
    
    Title:Date:
     Nov 14 2007
    
    
    
    Date:
 38




---



##### 



Date:
    
    August 27, 2007To:
    
    Mitel US Holdings, Inc.
    
    From:
    
    Morgan Stanley Capital Services Inc.Attn:
    
    Douglas McCarthy
    
    Contact:
    
    New York Derivative Client Services GroupFax:
    
    613 591 2320
    
    Fax:
    
    212 404 4726Douglas McCarthy@mitel.comTel:
    
    613 592 2122 ext. 4431
    
    Tel:
    
    212 761 2996
 Re: Rate Swap Transaction MSCS Ref. No. HRSK9
    
    RL
      Party A:
    
    Morgan Stanley Capital Services Inc.Party A Credit Support:
    
    Payments guaranteed by Morgan StanleyParty B:
    
    Mitel US Holdings, Inc.Trade Date:
    
    August 27, 2007Notional Amount:
    
    USD 215,000,000Effective Date:
    
    October 31, 2007
 1




---



##### 



Termination Date:
    
    October 31, 2009, subject to adjustment inaccordance with the Modified Following BusinessDay Convention.Fixed Amounts:Fixed Rate Payer:
    
    Party BFixed Rate Payer Payment Dates:
    
    The last day of each January, April, July andOctober, commencing on January 31, 2008, up toand including the Termination Date, subject toadjustment in accordance with the ModifiedFollowing Business Day Convention.Fixed Rate:
    
    4.85%Fixed Rate Day Count Fraction:
    
    Actual/360Floating Amounts:Floating Rate Payer:
    
    Party AFloating Rate Payer Payment Dates:
    
    The last day of each January, April, July andOctober, commencing on January 31, 2008, up toand including the Termination Date, subject toadjustment in accordance with the ModifiedFollowing Business Day Convention.Floating Rate Option:
    
    USD-LIBOR-BBADesignated Maturity:
    
    Three (3) monthsFloating Rate Day Count Fraction:
    
    Actual/360Spread:
    
    InapplicableReset Dates:
    
    The first day of each Calculation PeriodCompounding:
    
    InapplicableBusiness Days for Payments:
    
    New York and LondonCalculation Agent:
    
    Party A, or as specified in the Agreement
   2




---



##### 



Payments to Party A:
    
    As per Standard Settlement InstructionsPayments to Party B:
    
    Please ProvideDocumentation Contacts:
    
    Institutional ClientsHotline: +1 212-761-2996Facsimile: +1 212-404-4726Email: Derivative.Confirms.Americas@morganstanley.comOperations Contact:
    
    Tel +1 212 761 4662Fax +1 410 534 1431
    BY:
    /s/ David N. MooreName:
    David N. MooreTitle:
    Vice President   BY:
    /s/ Steve SpoonerName:
    Steve SpoonerTitle:
    President 3