Preview Tool

Cisco Bug: CSCta68310 - CM should be able to choose between G711 companding on intercluster SIP

Last Modified

Jul 17, 2017

Products (1)

  • Cisco Unified Communications Manager (CallManager)

Known Affected Releases


Description (partial)

CM should be able to choose between G711 companding on intercluster SIP trunk
When a SIP audio media are negotiated for a G711 call on a callmanager to callmanager  SIP trunk, the chosen companding is always U-law due to the order of the codecs in the SDP. It would be more beneficial in some circumstances to choose G711 a-law. Below is an example


The original call from the phoneA to a phone CM1 is A-law, this phone then transfers the call to a phone on CM2 the call across the SIP trunk is U-law.  Finally the call is transferred to phone B, this path uses A-law

So finally we have,  A-law—U-Law---A-law, with transcoding taken care of the differences. This may not be optimum use of resources and if A-law could have been chosen for the intercluster  trunk it would be more efficient

Related Community Discussions

UCCX 8.0 support G711 a-law?
Hi All, Could somebody please help confirm if UCCX/IPIVR 8.x supports G711a-law codec??. And if so try and force UCCX to use 711alaw and nothing else. We seem to be facing an issue, where we require Xcoder resources on IVR Trigger/Call control groups. All calls coming in through SIP provider using G711alaw and require Software MTP on GW and MTP required checked for the success of SDP to be included in first invite. Thanks, Yavuz
Latest activity: Dec 20, 2010
Bug details contain sensitive information and therefore require a account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.