[asterisk-dev] SDP negotation problem

[Kevin P. Fleming]

Salvatore Frandina wrote:

> I'm using SIPp program to make a call toward Asterisk PBX. The SIP call
> works well with Asterisk 1.6 (1.6.0.x, 1.6.1.x and 1.6.2.x) but not with
> Asterisk 1.4.x. After I have analyzed the sip message between SIPp and
> Asterisk 1.4.29 I have discovered a discrepancy in SDP message.
> The RTP payload type is different: SIPp sends 96 dynamic payload type
> for H263-1998 - H264 while Asterisk response 103 dynamic type for
> H263-1998 - H264. Why? With the other versions there are not problems.

SDP offer/answer does not require that both ends use the same payload
type numbers for matching payloads; they can differ and it's perfectly
acceptable. This is not an error.

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
skype: kpfleming | jabber: kpfleming at digium.com
Check us out at www.digium.com & www.asterisk.org