Session Initiation Protocol (SIP) is a Internet Engineering Task Force
(IETF) standard for multimedia communication and conferencing over IP.
Telephone calls, video, instant messaging/presence, etc. can be
supported.
SIP Trunk - Cisco Unified CallManager SIP Trunk signaling
interfaces connect CallManager clusters with external SIP User Agents,
such as SIP gateways, applications, and SIP proxy servers. Applications
which handle SIP calls, but do not need to register SIP endpoints or
use line-specific SIP features can be implemented using SIP trunks. SIP
presence subscription (SIP/SIMPLE) is also supported via SIP trunks.
SIP Line - Cisco Unified CallManager SIP Line features
provide SIP
registration services, as well as SIP feature support for additional
capabilities required by desktop phones/soft-phones.
SIP Transparency and Normalization - Cisco Unified Communications Manager and Session Management Edition
provide a set of features called SIP Normalization and Transparency to
customize SIP internetworking with external SIP providers.
Normalization is the process of transforming inbound and outbound
messages, while Transparency allows SIP information to be passed
through from one call leg to another. The Normalization and
Transparency feature uses Lua scripts which are associated with SIP
Trunks. The scripts operate on inbound and/or outbound SIP
messages. Almost any information in a SIP message can be transformed or
passed through by SIP Normalization and Transparency.
