关键词: 符号化一致性关系, 一致性测试, 输入输出符号变迁系统（IOTS）

Abstract: Protocol conformance test is used to verify the conformance of the protocol implementation.The conformance relation is the foundation of the test generation.A mount of data are usually carried in the control messages in network protocols.A symbolic model of conformance relation is proposed in this paper for this property.Firstly，an input/output symbol transition system（IOSTS） for network protocols is set up.A corresponding semantic model is established according to the policy of data symbol instantiation.In this model，the activities of system are integrated of controls and data.Secondly，a symbolic conformance relation for test suite generation is given based on IOSTS.Finally，this conformance relation is simplified for automatically generating test suite.All data processes are modeled with symbolic variables so that data are not manipulated in real values but in uniform symbols.The symbols are instanced only if necessary.In this way，the abstract level of model is improved.The complexity of processes is also reduced and test suite can be generated much more automatically.Neighbor discovery protocol in IPv6 protocols is used to demonstrate the symbolic conformance relation.

Key words: symbolic conformance relation, conformance test, Input/Output Symbol Transition System（IOTS）