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It could be any voicemail system- whatever the Dispatchers are calling.
I've tested it calling into the Cisco CUE for testing, but it needs to work with any system.
Where can I look for information on DTMF relay and basic SIP phones?
Well, some of what you need to look at depends on the call flow. You need to take a look at the voice gateway (if issues with external calls or inbound calls to your own systems) to see which DTMF option is applied (i.e. dtmf-relay h245-alphanumeric vs. dtmf-relay ntp-nte. If you are calling into a system (such as CUE) that is internal but integrated via SIP trunk, then you'd have to look there as well. There are a two types of DTMF in that it can be in-band or out-of-band. Out-of-band passes via signaling (i.e. H323, SIP, etc.) and in-band is RFC2833. This can also be complicated by the actual endpoints involved - such as in your case, you are using a (presumably) 3rd-party SIP endpoint and having issues. It may be beneficial for you to open a TAC case as they can help troubleshoot the call flow and have a better look at the actual problem.
Knowing what Cisco calls it is a big help in opening a TAC.
The vendor of the basic SIP phone (Avtec) seemed to say they would normally use 2833...at least from the Wireshark capture I did showing what was sent.
Looks like something is not properly enabled.
There is no separate SIP trunk enabled for those phones (at least none show up).
They do make normal calls just fine, the only limitation is entering DTMF during the call.
thanks for the ideas!
We are having this issue as well with our new Avtec consoles. Did you get this resolved, and if so, can you point me in the right direction?
No, I never did get this resolved.
I didn't open a TAC and got busy putting other fires out and just haven't gotten back to it.
I did get the phones (and radio enpoints) recording with our Eventide recorder from the Avtec console.
I had a Cisco tech help out with this. It looks like Avtec is using KPML (and I don't think that's in keeping with RFC2833). We had to change the "DTMF Signaling Method" on the trunk configuration to "OOB or RFC2833". I think you also need to enable an MTP but I'm not positive on that. Hope that helps!
I have not had time to revisit this issue at all.
I'll have to see our current setup.
I didn't make a SIP trunk for those console phones (unlike the recording, which I needed to do). So I'll have to remember where to make trunk changes.
Might be above my permissions, but I'll start to look into it.
You have it working now?