SIP and incoming DTMF tones

Look at 15-03-03.

Thank you for the suggestion. The user still cannot acknowledge the alarms. Are there some sort of logs I can look at?

Your out of band signaling for SIP isn't setup then.

As CoralTech rightly noted, 15-03-03 must be set to 'Special' for your SIP endpoint Win911 to get RTP Events (DTMF). You should run a Wireshark on that machine's interface and watch Wireshark when the called party dials digits. Dial a fixed known sequence so you can track it in Wireshark. Once you've stopped that capture, go to Telephony/VoIP Calls/ highlight the stream and click 'Flow Sequence.' You should see the RTP/DTMF events showing which digits were pressed. If you're testing with a generic SIP endpoint like MicroSIP or a 3CX softphone, you won't hear the DTMF digits because they are out-of-band. You also might check if your 84-34 settings for SIP Extension are RFC2833 and payload 101. but I don't thing they are strictly necessary for this particular usage.
The next question would be - Does Win911 recognize them?

BTW, if you're testing with MicroSIP you may already know to 'Allow IP Rewrite' since RTP is coming from the IP address of the NEC VOIP DSP interface address, not the VOIP control interface.

Ok, slight correction. MicroSIP actually interprets the RTP Events and presents them audibly, whereas 3CX does not. Go figure.

I have it working now. My VoIPDB DTMF was not setup. CoralTech was a real help in getting this resolved.