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CCM - CME transfer not working


i have scenario where CCM is configured with CME using ICT-non GK controlled.

ip phone on cme calls ccm ip phone 1 and the ip phone 1 tries to transfer to ip phone 2 in ccm this does not work.

I am wondering where i need to look to troublshoot this issue.

CME:4.1 and CCM:4.3

Good day


Re: CCM - CME transfer not working

why u dont make the CME as H323 gateway on the CCM and make the proper dial-peers on CME


According to Cisco press:

When there is a call transfer for an H.323 call from one Cisco CallManager IP phone (phone A) to another (phone B), the H.323 signaling path does not change. It remains terminated on the Cisco CallManager server. The Cisco CallManager server establishes a new SCCP signaling path to phone B. Of course, the media path also has to change. Changing the media path on the IP phones is easy. The Cisco CallManager simply sends the appropriate SCCP messages to phone B, telling it to participate in the media connection to the external H.323 endpoint

To change the media connection on the H.323 side, the Cisco CallManager uses a mechanism known as Empty Capabilities Set (ECS). This mechanism informs the external H.323 device that it should stop sending its media packets to phone A's IP address and should instead send the media packets to phone B's IP address. This mechanism allows the media stream to be redirected to the transfer-to destination phone while preserving the original H.323 control path connection

MTP that can provide transcoding services. One example of this type of MTP is the digital signal processor (DSP) farms that are supported on Cisco IOS voice-enabled routers. DSP farms are controlled by a Cisco CallManager (or Cisco CME) using the SCCP protocol. The term transcode means the ability to convert the media stream from one codec type to another. You may sometimes see this term abbreviated as xcode.

The drawback to this approach is the impact on overall scalability, because an MTP channel is needed for every H.323 (external) call

good luck

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