A Scalable Multi-Server Cluster VoIP System

摘要

A Peer-to-peer mode is a desirable operation mode for SIP based VoIP system since it will pose a least traffic load to the network. However, the operation will usually fail when one or both of die clients are behind a NAT or firewall. Using a server-client mode operation can usually solve die NAT problem, but die transmission delay reduction is a challenging problem when the server load is high, hi order for the VoIP system to operate efficiently, it is necessary to keep die system in die peer-to-peer mode whenever possible, hi this research, a multi-server cluster VOIP system is proposed. This server cluster consists of a peer-to-peer based master server with a group of slave servers. The slave servers will normally operate in die client-server mode. For a service that does not need client-server operation, me master server will directly handle die necessary SIP signaling and leave die clients in me peer-to-peer mode for their data stream transmission to reduce me network load. If a service needs to operate in a client-server mode, one of die slave server will be chosen for die operation. Depending on die server load and other factors, die number of me slave servers can be changed accordingly.