On 01/10/2011 03:59 AM, Olle E. Johansson wrote: > The draft changes the SDP offer/answer model so that an answer has to use the > same protocol family (ipv4/ipv6) as the offer, which makes sense. > > > Two things remain unclear to me: > > - If I get an offer for media based on an address family I can not understand > - what's the valid response? > If it's only one media stream with codecs I don't support, I use 488. But > in this case that doesn't seem > like a valid response to me.
488 Not Acceptable Here seems reasonable to me; in that case, the media offer is not acceptable, as your endpoint cannot use the requested transport mechanism. > - Is there a way to compose an offer with two media streams - one in IPv4 and > one in IPv6 - for dual > stack agents. I can't find examples of this, but SDP syntax seems to allow > it. The draft propably > should go a bit deeper in this area. With the text on ICE it seems to > recommend sending an > offer with both networks, then using ICE to find the optimal path for > media. Discussions on the IETF lists have pointed to ICE being the *strongly recommended* way to offer both IPv4 and IPv6 candidate addresses for a media stream, if for no other reason than that usage of ICE also mandates connectivity checks to determine which candidate(s) are actually suitable for use. -- Kevin P. Fleming Digium, Inc. | Director of Software Technologies 445 Jan Davis Drive NW - Huntsville, AL 35806 - USA skype: kpfleming | jabber: kflem...@digium.com Check us out at www.digium.com & www.asterisk.org _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
