Mail Stop 3720 							February 28, 2006 Via U.S. Mail and Fax (412- 820-1530) Mr. Samuel C. Knoch Chief Financial Officer Tollgrade Communications, Inc. 493 Nixon Road Cheswick, PA 15024 	Re:	Tollgrade Communications, Inc. Form 10-K for Fiscal Year Ended December 31, 2004 		Filed March 3, 2005 Form 10-Q for Fiscal Quarter Ended September 24, 2005 		File No. 0-27312 Dear Mr. Knoch: 	We have completed our review of your Form 10-K and related filings and do not, at this time, have any further comments. 								Sincerely, 								 /s/ Kyle Moffatt for 								Larry Spirgel 								Assistant Director ?? ?? ?? ?? Mr. Robin N. Dickson Harmonic Inc. Page 1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 DIVISION OF CORPORATION FINANCE