dtmf relay

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Jan 13th, 2010
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I hve a cucm6.0 connecting to a h323 gateway. calls to external ivr's are being setup without a problem, but when i try to send dtmf to the remote ivr, nothing is being received by the gateway.

voice-card 1
dsp services dspfarm


voice call convert-discpi-to-prog
voice rtp send-recv
voice class codec 1
codec preference 1 g711alaw
codec preference 2 g711ulaw
codec preference 3 g729r8
codec preference 4 g729br8

voice class h323 1
h225 timeout tcp establish 3
h225 timeout setup 3

no voice hpi capture buffer
no voice hpi capture destination

interface Serial1/0:15
no ip address
no logging event link-status
isdn switch-type primary-net5
isdn incoming-voice voice
no cdp enable

dspfarm rtp timeout 60
dspfarm codec g729 vad disable
dspfarm connection interval 60

dial-peer voice 1 pots
voice cut-through alert
destination-pattern .T
port 1/0:15
forward-digits all

dial-peer voice 100 voip

preference 1
destination-pattern xxxx
voice-class codec 1
voice-class h323 1
session target ipv4:x.x.x.x
dtmf-relay h245-alphanumeric
ip qos dscp ef signaling
no vad

Thanks in advance,


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asandborgh Wed, 01/13/2010 - 05:55
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I am unlcear on what you mean by external versus remote.  If you could clarify that it might help.

Additionally, if the IVR you are calling is through an H323 trunk or gateway try unchecking the "Wait for Far End H.245 Terminal Capability Set" box.



Johannes Snyman Wed, 01/13/2010 - 06:16
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Hi Art,

With both external and remote, i mean that the ivr doesn't belong to my company, but sits out on the PSTN. i have already unchecked the /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} "Wait for Far End H.245 Terminal Capability Set" box. the topology is as follows:

Cisco IP Phone==>CUCM6==>h323 Gateway (3640)==>PSTN (through E1 PRI)

i think that the problem lies between the CallManager and the gateway, because debug h245 asn1 doesn't show dtmf being received by the gateway.

asandborgh Wed, 01/13/2010 - 06:28
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ok - one further clarification - so if I understand the scenario you have two different IVRs that are accessed via the PSTN - one works with DTMF and the other does not - true?

If this is the case please run debug isdn q931 and place a call to each one so we can see a successful call and a failed one - in terms of DTMF.



PS, have you tried fast start on the gateway?

Johannes Snyman Wed, 01/13/2010 - 07:28
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Hey Art,

just when you think you've seen it all...

problem is fixed, and to tell you the truth, the solution is pretty embarrassing. i have two voice gateways at this particular site, one for routing pstn calls, and one for routing cellphone calls. one of the junior guys had added a more specific route pattern to the cellphone partition, which forwarded all the pstn numbers for the external ivr's to the cellphone gateway, which isn't set up for dtmf relay. once i had corrected the route patterns, everything started working normally.

anyways, thanks for your interest, i really appreciate it!!



asandborgh Wed, 01/13/2010 - 07:32
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np - glad to hear it's fixed




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