This paper proposes a TCL-based distributed protocol test system(DPTS).DPTS is practicable,interface-friendly,platform-independent and extensible.Most conformance tests on IPv6 protocols have been realized and some test cases are summarized in this paper.

The problem that how to place the smallest observers in passive testing and assure they can monitor all the behavior of a network was studied.First the problem was modeled as an instance of vertex cover problem which was an NP-Complete problem.Then the solution to the weighted and unweighted vertex cover problem was discussed in the special case that the topology of network is a tree,and linear time algorithms for weighted vertex cover problem were proposed.Based on an existing algorithm whose approximate rate is 2,an improved algorithm for unweighted vertex cover problem on graphic topology was proposed by combining with the algorithm for unwighted vertex cover problem on tree topology,and a simulating experiment showed the improved algo- rithm can reduce the number of the observers by about 20%.

A method for applying statistical observations in passive testing based on finite state machine(FSM) was introduced.Based on the Markov chain model,a new fault detection algorithm was proposed and a single fault diagnostic was discussed.Compared with those existed algorithms,the new approach only requires knowledge of the probability distribution of the transitions and the observed input/output pairs,and it can potentially be used in testing/monitoring distributed systems.

UIO (Unique Input Output) test sequences are widely used in communication protocol testing. In this paper, based on an existing fault diagnosis algorithm, an improved algorithm, which utilizes as much information of UIO test sequences as possible, is proposed. This paper full uses of verdict information given by UIO test sequences and the observed input/output immediately after the potential faulty transition to guarantee the efficient diagnosis of any single fault. Some experiments to compare the algorithm with the original one are conducted and the results show that the algorithm is more efficient.

A lot of research work has been done for conformance testing of protocols based on the FSM model. After a fault has been detected, it arises the problem that how to diagnose the fault. In this paper, it is assumed that IUT (Implementation Under Testing) exists only one single fault and a fault diagnosis algorithm is proposed. The diagnosis algorithm makes full use of transitions confirmed to be correct and head states set of the next observed input/output pair to the symptom transition and guarantees the diagnostic of any single fault in an FSM. In this paper, the comparison of time complexity with other existing fault diagnosis algorithms is given and an example to demonstrate the algorithm is presented.

在被动测试中如何放置观察者使得放置的数目最少并且能监视整个网络的运行情况是一个很有实际应用价值的问题.先证明了该问题是一个NP完全问题;接着讨论了在网络拓扑是树的特殊情形下该问题的解,并给出了针对树结构的一个线性时间算法;然后在一个已有的近似比为2的算法基础上给出了一个改进算法并证明了其近似比为2-O(1),最后用实验来验证了改进算法的有效性,指明了进一步的研究方向.

IPv6 will definitely be the dominant protocol of the next generation Internet. How to test these implementation versions of IPv6 from different manufactures is an important problem. Researches on the conformance testing of IPv6 are summarized in this paper. Also, a new Distributed Virtual Testing Method is presented. Finally, a testing system based on this new method is shown and the results of testing some kinds of IPv6 implementation are analyzed.

随着各具特色的形式化方法不断涌现.研究各种形式化模型之间的关系,并且通过组合、集成的方法,综合它们的特性,不仅在理论上,而且在实践中都具有非常重大的意义.将集成Petri网和Z语言两种形式化方法,使它们能够保留各自的优点,并互相弥补不足,进而形成一种新的、更加全面的形式化方法PZ网.