34.229-43GPPInternet Protocol (IP) multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP)Part 4: Enabler for IP multimedia applications testingRelease 11TSUser Equipment (UE) conformance specification
SIP is a text-based protocol, the messages exchanged between the UE and the SS are character strings. In TTCN-3 Test Suite the messages are structured to take the advantage of TTCN-3 functionality, and to make the debugging and maintenance of the Test Suite easier. When the TTCN-3 Test Suite sends a message to the UE, the SIP TTCN-3 codec converts the structured message to the corresponding character string then transfers it to the UE. When the SS receives a message from the UE, the TTCN-3 codec converts the received character string to the structured message and passes it to the TTCN-3 Test Suite.