VG224 and RFC 2833 DTMF Digit Relay feature

[CapriciousX]

Hello Guys,

I have read about the RFC 2833 DTMF Digit Relay feature , which is automatically turned on on IOS Gateways and Callmanager 5 + . As I understand, it sends DTMF tones as RTP packet through the network. Exactly what I want, but I am not sure of my VG224s doing it for sure. I have seen a list of phones, whos supporting this feature, but VG224 wasn't mentioned.

Can somebody confirm this feature for VG224? Further I have read that one can disable it on the CM. I couldn't find anything on service parameters...

Thanks,

Capri

[Nathan Compton · Accepted solution]

I'm not entirely sure for your situation, but I know if you are connecting the VG with SCCP, then the dtmf would be in the skinny messaging.

Adam Compton

[CapriciousX]

I have dug deeper and the RFC 2833 DTMF Digit Relay feature means, that in fact DTMF Tones are still recognize and send as "name" (and not as voice signal", but transferred within a RTP Packet. Sometimes both is used, sending DTMF as tone and name event.

http://www.faqs.org/rfcs/rfc2833.html

As mentioned this feature sending the DTMF within RTP packet is default by Callmanager 5+ according to Cisco documentation.