Exhibit 4.30

EXTENSION OF WAIVER TERMINATION DATE

March 30,
2005

Inter-American
Development Bank
Private Sector Department
1300 New York Avenue, N.W.
Washington, D.C. 20577
Attention: Loan Administration Unit

Export
Development Canada
151 O'Connor Street
Ottawa, Ontario
Canada
K1A 1K3
Attention: Special Assets Unit

Ladies
and Gentlemen:

Reference
is made to (a) the Eighth Amendment and Limited Term Waiver Agreement dated as of February 13, 2004 (as amended, supplemented or otherwise modified as of
the date hereof, including by means of a letter agreement between SRT, the Borrower and the Senior Lenders dated February 14, 2005, the "Eighth
Amendment") between among SR Telecom Inc., a corporation duly organized and validly existing under the laws of Canada
("SRT"), Comunicación y Telefonía Rural S.A., asociedad
anónimaduly organized and validly existing under the laws of Chile (the "Borrower"), Export Development
Canada (formerly Export Development Corporation), a corporation established by an Act of the Parliament of Canada ("EDC"), and Inter-American
Development Bank, an international organization established by the Articles of Agreement among its member countries ("IDB", together with EDC, the
"Senior Lenders"). Capitalized terms used herein and defined in the Eighth Amendment shall have the same respective meanings herein.

Pursuant
to Section 6 of the Eighth Amendment, the Eighth Amendment will expire upon the earliest date of occurrence of any of the events listed therein.
Section 6(a) of the Eighth Amendment lists March 31, 2005 as one such event. In view of the fact that SRT continues to discuss with debenture holders and other creditors a
possible restructuring of outstanding debentures together with possible new debt facilities, which transactions will require the consent of the Senior Lenders and the final terms of which are
anticipated to materially impact the scope and terms of such consent, each of the parties hereto agree, subject to the conditions specified in the last paragraph of this letter, that:

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(1)   Section 6(a) of
the Eighth Amendment is hereby amended in its entirety to read as follows:



(2)   Section 6
of the Eighth Amendment is hereby amended by replacing the text in Section 6(j)(ii) in its entirety with the following:



(3)   Section 6
of the Eighth Amendment is amended by (a) replacing the numerals "$45,000" in Section 6(k) with the numerals "$150,000" and
(b) replacing the words "February 18, 2005" in Section 6(k) with the words "April 15, 2005".

(4)   Section 10(l) of
the Eighth Amendment is hereby amended by deleting the "." and at the end of such section and inserting "; and" in place thereof; and

(5)   Section 10
of the Eighth Amendment is hereby amended by inserting the following subsection after Section 10(l):



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Each
of SRT and the Borrower covenants and agrees that the Transaction Documents and the provisions thereof are and remain legal, valid and binding obligations of each of SRT and the
Borrower enforceable in accordance with their terms, and remain in full force and effect except as amended or modified hereby, and each of SRT and the Borrower hereby reaffirms, reconfirms and
restates, all such obligations, as so modified, to the Senior Lenders. Each of SRT and the Borrower hereby expressly acknowledges and agrees that nothing in this letter or in any document or
instrument executed in connection with or pursuant to this letter shall constitute a satisfaction as to all or any portion of the Obligations.

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The
amendments provided in this letter shall become effective on the date on which each of the Senior Lenders shall have received an executed a counterpart of this letter from each other
Senior Lender, the Borrower and SRT.

| |  |  |  | Very truly yours,                  
| |  |  |  | -----------------------------------
| |  |  |  | SR TELECOM INC.                    
| |  |  |  | By                                 
| |  |  |  | By                                 
| |  |  |  | COMUNICACIÓN Y TELEFONÍA RURAL S.A.
| |  |  |  | By                                 

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|ACKNOWLEDGED, ACCEPTED AND AGREED
|---------------------------------
|EXPORT DEVELOPMENT CANADA        
|By                               
|By                               

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|INTER-AMERICAN DEVELOPMENT BANK
|-------------------------------
|By                             

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