Summary

             This Recommendation provides the general principles associated with ISDN test calls originating from a test system and terminated by a test call responder. It lays down the requirements associated with test calls and lists the facilities that should be provided by a test call responder.

             Keywords

             –     bearer type;

             –     ISDN network;

             –     ISDN nodes;

             –     ISDN test calls;

             –     teleservice;

             –     test access;

             –     test responders;

             –     test systems.