Research Of Fault Management And Rule-based Event Correlation In VoIP Networks

Because of the richness of VoIP protocol stack, the interaction and interconnection of singling and media gateways are much complex than the pure OSI model. VoIP network's device coverage is very broad, the classical PSTN PBX, the IP router and switch will be integrated into the same network. So there will be some difficulties to do event management and fault management within a VoIP network.Although currently there is plenty of research on event correlation and network fault management topics, these researches do not focus on applying its findings to VoIP networks. VoIP network differs a lot from the traditional telecommunication network, so the classical network management mechanisms or the ones aiming at IP network do not always work in the VoIP network environment.This thesis researches into the event collection mechanism, event correlation and fault management in VoIP context. By collecting and analyzing the system logging from soft-switches, SIP proxies and media gateways, and through the automatic diagnosis, the rule-based event correlator will deduce the root cause and apply fault management and recovery in order to achieve higher availability, security and manageability of the VoIP network.First, an analysis of SEC and Cisco IOS EEM technology is presented. After doing the performance test for SEC under various environments, the author clarifies the feasibility to use SEC for logging event processing when the size of rule set is appropriate. Based on it, a fault management framework to unify and correlate events in a hybrid VoIP network is proposed and implemented. Finally, this implementation is used in a real fault scenario, thus it is proven to be able to carry out the intelligent fault management in a VoIP network.