Cisco IP Phones, Regions, and Codecs

[shazlett]

When you use Regions & Locations to determine CAC (Central Site Call Processing example; G.711 for within a LAN location and G.729a between all locations via a WAN) does the Call Manager handle the codec selection and then notifies each end station of that selection? I would like some documentation that refers to this. The sections regarding Regions and CAC only refer to the codec as a metric for CAC calculations.

Need to know when and where and how the IP Phone determines which to use. Also what happens in the case of a mismatch configuration? Will the CM invoke a transcoder?

Thanks

[Daniel Baum]

Steve, detailed question(s), but, will attempt a response. If you still need further info, let me know.

The media resource manager makes Cisco CallManager able to deploy media termination point, transcoding, conferencing, and music on hold services.

Media resource management provides access to media resources for all Cisco CallManagers in a cluster. Every Cisco CallManager contains a software component called a media resource manager. The media resource manager locates the media resource that is necessary to connect media streams to complete a feature.

The media resource manager manages the following media resource types:

Transcoder (XCODE)

Music On Hold (MOH) server

Unicast conference bridge (CFB)

Software media termination point (media streaming application server)

The Cisco CallManager invokes a transcoder (if defined and available - MRGL) on behalf of endpoint devices when the two devices use different codecs and would normally not be able to communicate. When inserted into a call, the transcoder converts the data streams between the two incompatible codecs to enable communications between them.

This document, I believe, explains well media resource management of CallManager.

http://www.cisco.com/univercd/cc/td/doc/product/voice/c_callmg/3_3/sys_ad/3_3_3/ccmsys/a05media.htm

Dan