Systematic testing of protocol robustness: case studies on mobile IP and MARS

Systematic testing of robustness by evaluation of synthesized scenarios STRESS is a methodology developed for the systematic testing of protocols, and includes algorithms for generating topologies and event sequences that rigorously test the correctness or performance of a given protocol. In this paper, we apply the STRESS method to mobile IP (MIP) and the multicast address resolution server (MARS) protocol for supporting IP-multicast over ATM. For each protocol, we develop a protocol model and analyze its robustness. We also analyze complexity of the STRESS test generation algorithms. In the process, we identify the limitations of the existing STRESS models and algorithms, and propose extensions to carry out our case studies. With the aid of STRESS, we were able to identify several protocol behaviors that lead to error or performance degradation. For MIP we identified such behaviors with the crash of a home agent or the loss of a registration message. For MARS undesired behavior was detected with the crash of the MARS server or source and the selective loss of a join or leave message. The complexity of forward search was found to be O(n/sup 2/) for both MIP and MARS. Incorporating the fault model in the search was found to affect the number of states searched. The crash of a home agent in MIP, and the crash of a data source or server in MARS, were both found to increase the number of states searched. However, the asymptotic complexity was not affected.