摘要 |
A communications system (10) includes a packet-based data network (12) that is coupled to various network elements (14, 16, 18, 20, 22, and 34) that are capable of participating in audio-based call sessions over the data network (12). The audio-based call sessions may be defined according to a Session Initiation Protocol (SIP) or to another type of protocol (e.g., H. 323). The network elements (14, 18, 22, and 34) are also capable of participating in text-based chat sessions. Text messages exchanged in such text-based chat sessions are earned in messages that are defined according to the protocol for audio-based call sessions. In one example, such messages may be SIP Info messages. The SIP Info messages carrying the text messages may be communicated either during an established audio-based call session or outside of an audio-based call session. Using SIP (or another signal protocol) messages to carry the text messages allows such messages to be conveniently transported through a firewall system.
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