SIP conformance testing based on TTCN-2

The session initiation protocol (SIP) is a signaling protocol for Internet telephony, multimedia conferencing, presence, event notification, and instant messaging. With the gaining popularity, more and more SIP implementations have been developed and deployed. How to guarantee the conformance of those SIP implementations is the key point of interconnection and interoperation among them. This paper proposes the test method and architecture for the SIP protocol based on the IPv6 tester system. Tree and tabular combined notation (TTCN-2) is adopted to describe the test suite. With an enhanced reference implementation, the data-processing ability to the original test system has been greatly improved. In the following test practices, some errors have been found in the SIP entities under test. It is proved that the proposed test method and architecture are effective to verify the conformance of the SIP entities, and the result of the conformance test may provide helpful reference to the development of SIP products.