COMMUNICATION SYSTEM AND METHOD FOR USING A MULTI-TIERED REGISTRATION SESSION INITIATION PROTOCOL

摘要

A communication system for using a multi-tiered registration session initiation protocol (SIP) includes: a client, a relay server and a plurality of SIP servers. The relay server is connected with the SIP servers and the client. The relay server is configured to establish a connection with the client and register with each of the SIP servers so as to select at least one of the SIP servers for direct communication with the client, thereby solving the conventional problem of incompatibilities existing between the client and SIP servers and between the SIP servers and further saving communication costs for the client in dialing various numbers.