UC500.com Cisco CallManager Express, UC500 reference

Thought I would give back a little to a community that has helped so much with a lot of CME and UC500 questions I've had. Here's an issue I ran into with the new 3911 and CME.

I was setting up the new Cisco 3911 phone to work with a CME 4.1 system and CUE 3.0. Following the SIP guide from this website, everything appeared to be working just fine. However, when I tried dialing into CUE, the system did not hear the DTMF coming from the phone. I checked and re-checked everything to make sure I had setup the phones and the CUE dial-peer correctly using 'sip-notify' as the DTMF relay type. It was correct, and I was getting nothing. Off to TAC we go...

After a couple of days of debugging and testing in their lab, it turns out that this particular phone was sending the DTMF in-band instead of out-of-band. That meant that 'sip-notify' wasn't sending any digits from the phone, and the CUE dial-peer wasn't setup to listen for in-band DTMF. That was when I was told that CUE 3.0 supports using 'rtp-nte' as the DTMF relay type. This was opposed to all the existing documentation I had seen that said CUE only supported 'sip-notify'.

This setting must be changed in 3 places:

1. On the voice register pool definition for the phone. use 'dtmf-relay rtp-nte'. Don't forget to recreate the phone profiles if you changing an existing system.

2. On the dial-peer for CUE. Again, under the dial-peer definition, use 'dtmf-relay rtp-nte'.

3. In CUE, under the 'ccn subsystem sip' section. Use 'dtmf-relay rtp-nte' to make sure CUE is listening in-band for DTMF.

That should be enough to get you working with the new SIP phones.