Instructions for the International Telephone Service

These instructions include Recommendation ITU-T E.141 which was withdrawn on 20 March 2003 by Circular 156.
- Click to access:
-
Click to download PDF - 517.09KBPDF
-
Click to Read online and shareREAD
.
Supervision of calls
- Click to access:
-
Click to download PDF - 116.24KBPDF
-
Click to Read online and shareREAD