Research And Implementation Of IPv6Specification Conformance Testing System

The explosive growth of the Internet has exposed some pitfalls of IPv4, such asaddress exhaustion, overloading of backbone routers’ route table capacity. IPv6, as thenext generation internet protocol, is to solve these problems, and at the same time to adaptto the future development of the Internet and internet service.IPv4-to-IPv6transition is a long-term process. In IPv6deployment, the compatibilityproblems among various IPv6implementations as well as between IPv6and IPv4systemsonly can be solved through thorough testing. In order to demonstrate interoperability,different vendors’ equipment firstly shall pass conformance testing. Conformance testingis the most important way to improve reliability of IPv6implementations.This paper discussed the conformance testing of IPv6specification aimed at designand implementation of a protocol conformance testing system. According to the featuresof IPv6specification, several aspects, such as test method, test case generation and testcase description, were taken into account in testing system design. Based on theseconsiderations, a conformance testing system adopting remote test method was designed.In the system, Tcl is used as the test case description language, and WinPcap is used forsending and receiving packets. Test case description commands were designed andimplemented, which is the critical part of testing system implementation. Finally, thetesting system was applied to several IPv6specification implementations and the resultswere analyzed. The results demonstrated the effectiveness of the testing system.This paper also pointed out some shortcomings of test case description in severalpublished papers that use Tcl as the test case description language, and made someimprovements. In the way of test case data description, a packet construction method wasdesigned. This method is convenient to construct a variety of normal or erroneous packets effectively. In the way of test case behavior description, the two procedures, packetreceiving and packet parsing, are encapsulated in only one Tcl extension command, whichneeds no prior assumption of the number of packets to be received. The former policy canavoid erroneous verdict when executing test cases under realistic network environments.