Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member


I have a 2851 with a PRI into a MFT card for connectivity to the PSTN. I also have an IVR system used for a telephone banking application. The customer calls a pilot number associated with the PRI and it gets translated to an internal hunt group. There are four DN’s in the hunt group connected to ATA’s which terminate into the IVR system. Everything was working fine until the gateway was converted from H.323 to MGCP in order to facilitate a request by the customer. Now we are getting complaints that the IVR system is not understanding certain digits the when the customer is trying to input their account number. I have this same ATA to the IVR system setup running at a few other customers using H.323 with no problems and we did not have any complaints until the switch to MGCP. I have not been able to track down if it is specific digits but the problem seems sporadic, some times the customer gets in and sometimes they do not. Here are some sections of the router config. I am running CCM 4.1.3. Any help would be appreciated.

network-clock-participate wic 1

network-clock-select 1 T1 0/1/0

ip subnet-zero

no ip source-route

voice class codec 100

codec preference 1 g711ulaw

codec preference 2 g729r8




voice class h323 100

h225 timeout tcp establish 3




voice class dualtone-detect-params 90

freq-max-power 6

freq-min-power 25

freq-power-twist 15

freq-max-delay 16

cadence-variation 8


controller T1 0/1/0

framing esf

linecode b8zs

pri-group timeslots 1-24 service mgcp


interface Serial0/1/0:23

no ip address

isdn switch-type primary-ni

isdn incoming-voice voice

isdn bind-l3 ccm-manager

no cdp enable

ccm-manager redundant-host

ccm-manager mgcp

ccm-manager music-on-hold

ccm-manager config server

ccm-manager config



mgcp call-agent 2427 service-type mgcp version 0.1

mgcp dtmf-relay voip codec all mode out-of-band

mgcp rtp unreachable timeout 1000 action notify

mgcp modem passthrough voip mode nse

mgcp package-capability rtp-package

no mgcp package-capability res-package

mgcp package-capability sst-package

no mgcp package-capability fxr-package

mgcp package-capability pre-package

no mgcp timer receive-rtcp

mgcp sdp simple

mgcp fax t38 inhibit

mgcp rtp payload-type g726r16 static

mgcp bind control source-interface Loopback0

mgcp bind media source-interface Loopback0


mgcp profile default

  • Other Collaboration Voice and Video Subjects
New Member





Well, I had a problem similar to this a while ago, but I had not added the 'mgcp dtmf-relay voip codec all mode out-of-band', since it had not occurred to me that it would not be default, and when I did a debug mgcp packet, it showed the digits being sent, and I thought if it was inband, it would not recognize and pull them out like that for the stats, but it did. Once I added that, everything was fine. I see that it is already in your config. Did you have to add it? If you did, have you synched the gateway since then? I have found some things don't seem to really 'take' unless I do a 'ccm config check reset' on the gateway, then 'sh ccm' to watch for the successful download, and try it again. Otherwise, it almost sounds like it is not really functioning. The only other thing would be if there was something drastically different between say the levels settings on the gateway, that was set one way in the H323 config, and is different in the CM config. Do you have that old config to compare?

Mary Beth



Digging around a little more, it looks like the mgcp dtmf relay should be default, so in my case it was likely removed by some creative person at some point, so I am guessing yours has been in there all along, and the config sync won't make any difference. If you have not changed the ata's at all, they should be behaving exactly as before, you could verify the audiomode is x0015, but that should have it negotiating dtmf relay out of band. Did you have dtmf relay on the dial peers when it was h323? I ran across a debug command for dtmf relay, but I am not sure if it will really work - debug voip rtp dtmf-relay, you could see if you get any output on a test call. It really acts like it is not doing it, but I am not sure how to prove it. I did not see anything specific in a bug search for dtmf relay and ATA, at least nothing current. I know there is a debug tool for the ATA called pserv, I have not used it, but you capture traces from the ATA to your pc, it might come down to doing that. I would think that there might be something in a CCM trace, too, that would help indicate if it was really doing dtmf relay - maybe grab one with a test when there is not much else going on.

Mary Beth

This widget could not be displayed.