ITU-T-Q.258 › Telephone Signals
ITU-T-Q.258
-
1988 EDITION
-
CURRENT
Telephone Signals
Document Number
ITU-T-Q.258
Revision Level
1988 EDITION
Status
Current
Publication Date
Nov. 1, 1988
ITU-T-Q.258
1988 EDITION
Current
Nov. 1, 1988