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Method to Signal Session Termination of a SIP-Initiated Group Multimedia Communication Session

IP.com Disclosure Number: IPCOM000012584D
Original Publication Date: 2003-May-16
Included in the Prior Art Database: 2003-May-16
Document File: 2 page(s) / 23K

Publishing Venue

Motorola

Related People

Matthew Keller: AUTHOR [+4]

Abstract

It is expected that future multimedia dispatch communication systems may employ the Session Initiation Protocol (SIP) as the means of controlling multimedia communication sessions. As originally envisioned, SIP defines a simple transactional protocol model to signal initiation, modification, and termination of communication sessions between peer entities. For public safety applications, it is desired that SIP be adapted to work as the signaling control protocol in group communication systems. Any group member wishing to control aspects of the session (e.g. initiating, modifying, or terminating) establishes a SIP control dialog with a SIP entity that represents the group (i.e. the group's “agent”).

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Method to Signal Session Termination of a SIP-Initiated

Group Multimedia Communication Session

By Matthew Keller, Ross Lillie, James Mathis, and Donald Newberg

It is expected that future multimedia dispatch communication systems may employ the Session Initiation Protocol (SIP) as the means of controlling multimedia communication sessions. As originally envisioned, SIP defines a simple transactional protocol model to signal initiation, modification, and termination of communication sessions between peer entities.� � For public safety applications, it is desired that SIP be adapted to work as the signaling control protocol in group communication systems.� Any group member wishing to control aspects of the session (e.g. initiating, modifying, or terminating) establishes a SIP control dialog with a SIP entity that represents the group (i.e. the group's “agent”).

While standard SIP semantics suffice for the initiation and modifications of communication session in such a scenario, SIP semantics for session termination don't provide the necessary semantics for the various session termination scenarios needed in a group communication context.� SIP semantics for session termination rely upon the SIP BYE request which terminates the dialog between the request's sender and the recipient.� In a group communication context, these semantics would suffice only to remove the sender from the group communication. However, in a SIP-initiated group communication session, multiple group members may have established SIP control dialogs with the group’s agent. As such, a richer set of termination semantics need to be defined to allow a finer gradation of control of a session's termination. For example, the sender of a BYE request may want to remove themselves from the session, may want to remove themselves from the session at a particular terminal only, may want to terminate the session for all members of the group, or may want to terminate the session for a subset of group members.

In order to provide additional control on the termination of sessions and media streams, the SIP BYE...