Private Telecommunication Networks (PTN)
- Signalling at the S Reference Point - Generic Keypad Protocol
for the Support of Supplementary Services (SSIG-KP)
2nd edition (June 1993)
The latest edition of this Ecma Standard is available here.
You can download the previous replaced "historical" edition of this Ecma Standard, free of charge:
|ECMA-156 1st edition
||Acrobat (r) PDF file