[asterisk-dev] why no sequence numbers with video frames over IAX ?

[Luigi Rizzo]

On Tue, Oct 30, 2007 at 08:27:28AM -0400, Russell Bryant wrote:
> Luigi Rizzo wrote:
> > sorry if it is a stupid question, but i was trying to tunnel
> > video through asterisk between SIP and IAX:
> > 
> > 	[A]----(sip)---[asterisk]---(iax)----[B]
> > 
> > (A is a windows softphone, B is asterisk with chan_oss video extensions)
> > and noticed that video ast_frames reaching B seem to have all the
> > same sequence number, f->seqno = 0
> 
> The reason is because IAX media frames (meta video frames in this case) do not
> carry a sequence number.  They do, however, carry a timestamp.  That is what
> must be used to handle reordering or other operations in a jitterbuffer.

ok thanks for the clarification.
The absence of sequence number makes it slightly difficult to detect
missing frames though... 

cheers
luigi