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Community Member

CallManager 9.1.1 Publisher and Subscribe

Hi, I have problem with CallManager 9.1.1 . When both Publisher and Subscribe are active it was observed echo when I comunicate with external number. But when I shutdown the Subscriber this problem disappear. I don't understand where are problems. Please, advise me where to look to solve this problem. Thanks advance, and excuse me for my English.

Community Member

Hi,Are the Pub and the Sub on


Are the Pub and the Sub on the same network site ?

What codec are you using between Ip phone and Gateway ? Is the Sub doing trancoding (Alaw/Ulaw) ?


Community Member

Hi,No, Pub and the Sub are in


No, Pub and the Sub are in different networks.  Audio codec between ip phone and gateway is G.711u and G.711a. How to verify if Sub is doing transcoding ? Thanks

Community Member

Hi vitali555md . Please

Hi vitali555md . Please install RTMT from the plugins menu on CM Administration.

You will be able to monitor the real-time calls and their associated transcoders

Community Member

HI, One thing let me think



One thing let me think about the fact the Sub is on another network is that the Sub was doing transcoding between IP phone ang the the gateway and the network latency was generating echo.

Could you monitore the switch port where the ip phone is plugged to determine from where are the rtp packets.

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