Hi,

>My feeling was that a-lines were associated with m-lines...
> 
>I still dont understand how you would read the first SDP: Make the
>sessions (ports 65422, (0), 53000) sendrecv, and the audio 
>session (port 51434) recvonly?!

That is how I would read it, yes. 

sendrecv is the default value, why it's not specifically indicated for the other 
m-lines, and in your first example a=recvonly applies only to the last m-line. Nothing 
stops you from putting a separate direction attribute for each m-line, though, as you 
have done in your second example.

I guess I missread your question the first time, though. I first thought that you 
meant that you would have the mode attribute in the session part of the SDP, ie BEFORE 
any m-line at all. In that case the attribute you have defined in the session part 
applies to ALL m-lines, unless you also have defined mode separately for one or more 
m-lines, in which case those have higher priority.

Regards,

Christer

> 
> CS
> 
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf 
> Of Christer
> Holmberg (JO/LMF)
> Sent: Monday, August 09, 2004 4:32 PM
> To: Christian Stredicke; Sip-Implementors (E-mail)
> Subject: RE: [Sip-implementors] RFC3264 - where to put attributes when
> several m-lines are available
> 
> 
> Hi,
> 
> I guess your issue is valid for most media level attributes, ie should
> it be allowed to define them on the session level of the SDP, (similar
> to the c-line), in which case they should be associated with all media
> descriptors.
> 
> For example, I had a discussion with Gonzalo if I can put a 
> media label
> attribute on the session level, if I want to use the same label value
> for multiple streams. And so on...
> 
> Or, is there any reason why only the specific mode attribute makes the
> whole thing "un-logical"?
> 
> Regards,
> 
> Christer Holmberg
> Ericsson Finland
> 
> 
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED] Behalf Of 
> > Christian Stredicke
> > Sent: 7. elokuuta 2004 23:13
> > To: Sip-Implementors (E-mail)
> > Subject: [Sip-implementors] RFC3264 - where to put attributes when 
> > several m-lines are available
> > 
> > 
> > I recently had a discussion where to put the a=sendrecv etc 
> attributes
> 
> > when there are several m-lines. The examples in RFC3264 
> seem to imply 
> > that there is only one attribute per SDP.
> >  
> > v=0
> > o=bob 2890844730 2890844731 IN IP4 host.example.com 
> > s= 
> > c=IN IP4 host.example.com 
> > t=0 0 
> > m=audio 65422 RTP/AVP 0 
> > a=rtpmap:0 PCMU/8000 
> > m=video 0 RTP/AVP 31 
> > m=video 53000 RTP/AVP 32
> > a=rtpmap:32 MPV/90000
> > m=audio 51434 RTP/AVP 110
> > a=rtpmap:110 telephone-events/8000
> > a=recvonly
> > 
> > However, it would be more logical if the attribute is included in 
> > every m-line segment. Like this:
> >  
> > v=0
> > o=bob 2890844730 2890844731 IN IP4 host.example.com s= c=IN IP4 
> > host.example.com t=0 0 m=audio 65422 RTP/AVP 0 a=rtpmap:0 PCMU/8000 
> > a=recvonly m=video 0 RTP/AVP 31 a=recvonly m=video 53000 RTP/AVP 32
> > a=rtpmap:32 MPV/90000
> > a=recvonly
> > m=audio 51434 RTP/AVP 110
> > a=rtpmap:110 telephone-events/8000
> > a=recvonly
> > 
> >  
> > Any ideas?
> >  
> >  
> > CS
> > _______________________________________________
> > Sip-implementors mailing list
> > [EMAIL PROTECTED]
> > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
> > 
> _______________________________________________
> Sip-implementors mailing list
> [EMAIL PROTECTED]
> http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
> 
> 
_______________________________________________
Sip-implementors mailing list
[EMAIL PROTECTED]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors

Reply via email to