[asterisk-biz] Solving DTMF issue

[Gregory Boehnlein]

> > This was only true with Asterisk up to and including 1.2; 1.4 and
> beyond
> > send proper RFC2833 (now RFC4833) DTMF telephone-events and
> > interoperability has been dramatically improved.
> 
> my patch was for 1.4 so that is not true.

What specifically does the 1.4 DTMF implementation break in terms of the
RFC? RFC-2833 is pretty vague about a lot of things, and most vendors
implementations (Cisco, Avaya, Sonus etc..) can be deemed to be "in
violation" of the RFC. For example Cisco doesn't respect DTMF duration
events, and clips DTMF upon receipt of a DTMF "end of event" marker.
Technically this violates the RFC.

In a lot of ways, the Asterisk RFC-2833 implementation is more compatible
(in 1.4) than most other stacks out there.