[asterisk-dev] Request for Comments: RTP out-of-band dtmf signalling for connections between asterisk and cisco equipment

[Andreas Brodmann]

2007/12/19, Russell Bryant <russell at digium.com>:
>
> Andreas Brodmann wrote:
> > 1) modifying the code so that the existance of 'x-nse' in the sdp body
> > is accepted as if
> > 'telephone-event' was there
>
> I think that this option would be fine, provided that we can find some
> documentation that verifies that "x-nse" is in fact the same thing.  From
> searching around, it looks like this has been used by Cisco stuff for
> quite a
> while, and it just happened to always work before the recent change to not
> include rfc2833 in the SDP if it was not offered to us in the initial
> INVITE.


The X-NSE is a supplement to RFC2833 and uses the same format. So if the
X-NSE occurs in
an SDP message this means that the other end supports rfc2833 plus the
X-NSE.

Explanation by cisco:
http://www.iana.org/assignments/media-types/audio/vnd.cisco.nse

I have attached a tiny patch to the bug report at
http://bugs.digium.com/view.php?id=11489

The patch applies against main/rtp.c and adds a new mimetype having the same
rtpPayloadType and type as 'telephone-event' but has 'X-NSE' as subtype.

-Andreas
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.digium.com/pipermail/asterisk-dev/attachments/20071220/5f0f78f6/attachment.htm