CCITT Rec. U.202 (11/1988) – REQUIREMENTS TO BE MET IN PROVIDING THE TELEX SERVICE WITHIN THE ISDN
1 Scope
2 Configuration models
2.1 Two configuration models may be developed:
3 General principles
3.1 Minimum integration model
3.2 Maximum integration model
4 Call establishment sequences
4.1 Minimum integration model
4.2 Maximum integration model
5 Terminal adapter functions
6 Adapter unit
7 Interworking facility functions
8 Other telex service features