Research on Security Mechanisms of SIP-Based VoIP System

The SIP-based VoIP system is build on the IP network, so it is affected by the IP network security problem. SIP-based VoIP system has many security problems because of the security mechanism of VoIP system and other external factors. These effects relate to the following three aspects: confidentiality, integrity and availability. This paper analyzed the mechanism of VoIP system and the components of SIP: SIP UA and SIP network server. The attacks on the SIP system, such as the registration hijacking, impersonating a proxy, denial of service and spam are discussed in detail. At last this paper points out the insufficiency of the SIP security mechanism, including certification attack, DoS attack and spam attack. SIP-based VoIP system involves so many security aspects that relational technology is used to assure the security of SIP-based VoIP system.