Media Renegotiation
First Published: November 19, 2010
This module describes the Media Renegotiation feature for the enhancement of the media setup process in the Skinny Client Control Protocol (SCCP) telephony control (STC) application (STCAPP) state machine. This feature enables media setup call flows to have improved interworking with third-party call control/Computer Telephony Integration (3PCC/CTI) that control analog endpoints behind IOS gateways.
Finding Feature Information in This Module
Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the “Feature Information for Media Renegotiation” section.
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Benefits of Media Renegotiation
Media Renegotiation enables media setup call flows to have improved interworking with 3PCC/ CTI that control analog endpoints behind IOS gateways.
This feature does not change the user behavior such that you do not notice any difference when you are having a call that experiences media renegotiation.
Information About Media Renegotiation
To enable SCCP supplementary features on analog phones connected to FXS ports on a Cisco voice gateway, you should understand the following concepts:
Media Renegotiation
In some customer environments, the media setup messages may arrive in a different sequence and involve a different protocol translation. If the remote side uses a different protocol from that of the calling phone, the media setup message sequence might be different.
Through Media Renegotiation, the media setup process in the STCAPP state machine can be enhanced to support any of the most possible sequences of the media setup messages.
Through this feature, media renegotiation can be introduced in the middle of a call and after early media (before and after the call is connected) is flowing.
The basic concept of the Media Renegotiation design is that no matter which media event is received, the event handler handles only the media direction that belongs to the event. For example, when an event involving the closure of the receiving channel is received, the event handler disconnects the receiving part of the media only, leaving the sending part unaffected in case the media path works both ways.
Additional References
The following sections provide references related to SCCP analog phone support for FXS ports on the Cisco voice gateway.
Technical Assistance
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Feature Information for Media Renegotiation
Table 1 lists the features in this module and provides links to specific configuration information. Only features that were introduced or modified in Cisco IOS Release 15.1(3)T or a later release appear in the table.
For information on a feature in this technology that is not documented here, see the “Supplementary Services Features Roadmap” section.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 1 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
Table 1 Feature Information for Media Renegotiation
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Media Renegotiation |
15.1(3)T |
Enhances the STCAPP state machine to support any of the most possible sequences of the media setup messages. The following section provides information about this feature:
No new commands were introduced by this feature. |