[asterisk-users] RFC2833 SIP trunks and DTMF

[Andrew Pogrebennyk]

Hello,

Jason Aarons (US) wrote:
> I have a telco providing DTMF inband, they say they can't provide it any
> other way. This is creating headaches for me.
>
> What is the common method for SIP DTMF? Kpml, or 2833 or inband?

Isn't RFC 2833 method of transmitting DTMF tone information the same as
inband? However that may be, among RTP-NTE, SIP INFO messages, SIP
NOTIFY messages and KPML I have seen SIP NOTIFY and SIP INFO more often
than others.

> My handsets don't support inband so I'm tying up some expensive
> resources to convert the inband  DTMF to out-of-band DTMF...
> 
> Can you recommend a vendor in US that provides SIP with DTMF in RFC
> 2833?

Maybe others may recommend, but not me.

-- 
/"\  Best regards,                     | andrew.pogrebennyk at portaone.com
\ /  Andrew Pogrebennyk                | http://callcc.livejournal.com/
 X   VoIP engineer                     | JID: marduk at jabber.lafox.net
/ \  ASCII Ribbon Campaign             | Against HTML Mail and News