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New Member

Voip with E&M drop lines in ten minutes talking

I have two sites connected by 256K leased line, each site has a cisco 2620 router connecting to PABX with 2 E&M module to fufill voip. The voip function good. but I find a strange issue, I call from one site to another through voip, the conversation can only last ten minutes, that means after ten minutes the line droped automatically. I checked PABX parameters setting, It seems nothing to do with PABX. Someone suggest to upgrade cisco router IOS, Can you tell me any suggestions?


Re: Voip with E&M drop lines in ten minutes talking

This is generally a PABX programming issue where the PABX is not provide answer supervision to the calls, so the router will wait a timeout period and then decide that since there was no indication of answer, it will drop the call. The best thing to do is to reconfirm the PABX programming and ensure the E&M ports have answer supervision enabled - once they do this the PABX should provide M lead response on answer and the router will know the call was successful. This also has the advantage of making Call detail records correct as well.

If you cannot get access to the PABX, add the following command to the voice port config to tell the router to ignore the M lead response and generate immediate answer -

voice-port 1/0/0


Bottom line is that this is a PABX issue.

New Member

Re: Voip with E&M drop lines in ten minutes talking

I have the same issue with a cisco 827. However, I made the voice call directly from one of the 4 ports on the back of the 827 (by-passing our pabx) The call terminates after 10 minutes. I saw the previous post about the work around for this, however, under my voice-port 1 interface, I don't have the option to set 'auto-cut-through'

Any suggestions would be much appreciated.



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