DTMF selection not working with SCCP phones

[Lukas Krejci]

Hi,

we have several cisco IP phones connected to the call manager (2911/K9), which is then trunked to the provider. Some of the IP phone (SPA303) are connected as SIP phones while others are using SCCP (CP-6921). The problem is, that when calling from the SCCP phones, DTMF selection does not wokring (e.g., when some robot is asking to make choice using the number keys). But, when calling from SIP phones, DTMF selection is working perfectly. 

Here is sample SIP phone config:

voice register pool 1
id mac 3CCE.73D2.BF6A
number 1 dn 8
dtmf-relay sip-notify
username rozvodna115kV password rozvodna115kV
codec g711alaw
!

And here is sample SCCP phone config:

ephone 1
mac-address 2C54.2D6A.98E4
max-calls-per-button 2
provision-tag 1
speed-dial 1 9588008040 label "Reditel"
speed-dial 2 9588008041 label "Sekretariat"
type 6921
button 1:1
!

Can you please give me some advice on how to fix the problem with DTMF selection on our SCCP phones?

Thanks & Regards

Lukas

[Brandon Buffin]

Lukas,

Do you have "dtmf-relay sip-notify" specified on the outbound dial peer(s) going to the SIP provider?

Brandon

[Lukas Krejci]

Hi Brandon,

this is my current outdound dial peer config:

dial-peer voice 2 voip
description "Outgoing ... "
translation-profile outgoing OUT
destination-pattern 9T
session protocol sipv2
session target ipv4:*.*.*.*
dtmf-relay sip-notify rtp-nte
codec g711alaw
no vad
!

Lukas

[Chakshu Piplani]

Hi Lukas,

Can you please provide the complete cal flow:

e.g IP Phone ->SCCP->CUCM->SIP TRUNK->GW->SIP->Provider

This will let us know the options where to apply dtmf command and on which dia-peer.

Also please try Brandon's suggestion.

If you are using h323 or sip trunk to gw can you try checking MTP on CUCM?

Regards,

Chakshu Piplani

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[Lukas Krejci]

Hi Chakshu,

the call flow from SCCP phones is as follows:

"IP Phone->SCCP->CUCM->SIP TRUNK->GW->SIP Provider"

Lukas

[Chakshu Piplani]

Hi Lukas,

Is MTP checked on CUCM on SIP trunk?

can you also provide me with the configuraion for the inbound dial-peer from CUCM to Gateway?

Regards,

Chakshu

[Lukas Krejci]

Hi Chakshu,

this is configuration for the inbound dial-peer:

dial-peer voice 1 voip
translation-profile incoming IN
session protocol sipv2
session target ipv4:*.*.*.*
incoming called-number .%
no voice-class sip tel-config to-hdr
dtmf-relay rtp-nte
codec g711alaw
no vad
!
 

Regarding MTP, I am not sure, what do you mean. Is it somewhere in the CUCM configuration?

Lukas

[Manish Gogna]

Hi Lukas,

There would be a "Media Termination Point Required" checkbox on SIP Trunk configuration page on CUCM ( Device > Trunk ). You can see if that is checked , if not you can check it and reset the SIP trunk. If the DTMF still fails you should collect the detailed callmanager service trace for that call from cucm to check if MTP is being invoked or if MTP allocation is failing. This also requires checking the MRGL assigned to the SIP trunk for correct MTP resource allocation.

If you see the following DTMF troubleshooting link, the second scenario is exactly what you have setup at your end

SCENARIO 2

• SCCP Phone-7941G, rtp-nte configured on gateway dial-peer

IPPhone--sccp--CUCM--SIP---Gateway---E1--PSTN

https://supportforums.cisco.com/document/144711/understanding-dtmf-negotiation-and-troubleshooting-sip-trunks

Manish

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[Lukas Krejci]

Hi Manish,

in the call flow in previous post, I refer to the Cisco 2911/K9 as "call manager" or "CUCM". But now from your post I assume, that "CUCM" is some kind of software application. I dont have this application - only the CLI. Is it possible to check MTP via CLI?

Regarding the "SCENARIO 2", I dont have much experience with Cisco VoIP configuration, so I dont understand, what is relevant or what should I change in my configuration.

Lukas

[Ayodeji Okanlawon]

Lukas,

You are not using CUCM, you are using CUCME.

Can you please try and add this command to the dial-peer facing your ITSP

dtmf-relay rtp-nte digit-drop

Test again..

Please confirm what is the firmware running on your 6921. There are quite a few bugs with this phone model

[Lukas Krejci]

After adding the command, nothing changed for 6921 phones - dtmf still not working.

The firmware running in 6921 phones is: SCCP 9.1.1.0

[Ayodeji Okanlawon]

Okay we can troubleshoot this in two ways

first of please remove the previous command I sent you and ensure you have only this as dtmf type

dtmf-relay sip-notify rtp-nte

Second you can try and upgrade the firmware on th ephone. That firmware is pretty old..

Thirdly we can collect logs and analyse whats going on..

Please do the ff:

conf t

service sequence-numbers
service timestamps debug datetime localtime msec
logging buffered 10000000 debug
no logging console
no logging monitor
default logging rate-limit
default logging queue-limit

Then..

<Enable debugs, then test again.>

debug ccsip messages
debug ephone state

debug voip rtp session named-event

<Enable session capture to txt file in terminal program.> (such as Putty)

then do the ff:

terminal length 0
show logging

Alternately you can take wireshark captures ( connect your pc to the pc port of the phone, esure wireshark is set to promiscous mode)

Send the logs/wireshark capture..include the call details ie called number, calling number

[Lukas Krejci]

I was trying to upgrade the firmware, but with no luck so far. After some searching, I have found, that my current CME version does not support another 6921 IP phone firmware version:

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucme/requirements/guide/cme86spc-htm.html

So, If I understand it correctly, to upgrade the 6921 firmware, I have to upgrade the CME itself, which means upgrading the whole IOS, is that right?

I have found, that latest version of CME for my C2911 is 10.5, which supports SCCP 9.2.1.0:

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucme/requirements/guide/cme105spc.html

So now, to the upgrade of IOS: Will the configuration remain intanct? Do I need to buy some license to upgrade the IOS?