On 04/09/2011 12:34 PM, Jean-Hugues Royer wrote: > Hi, > > What is the recommended behavior when you receive a SDP offer with a > RTP/AVP media protocol including a crypto attribute ? > > Ignore the media ? > Ignore the crypto attribute ? > Process it as a RTP/SAVP when SRTP is locally supported ? In that case > answer with a RTP/AVP or change it to a RTP/SAVP ? > > Is there any document that actually restricts the use of a crypto > attribute to a media with RTP/SAVP ? (RFC4568 doesn't) > > SNOM is one the several producers of such offers when they want to > optionally offer SRTP. > > Their argument for not using two medias (RTP/AVP& RTP/SAVP) by default > in the offer (as it should be) is that some proxies doesn't support > multiples medias, are you aware of such proxies ?
In addition, if an SDP offer contains multiple streams (one RTP/AVP and one RTP/SAVP) those are actually *separate* streams, not alternate offers for the same stream. As far as I know, the only RFC-compliant way to offer both RTP/AVP and RTP/SAVP for the same media stream is through SDP capability negotiation. -- Kevin P. Fleming Digium, Inc. | Director of Software Technologies Jabber: [email protected] | SIP: [email protected] | Skype: kpfleming 445 Jan Davis Drive NW - Huntsville, AL 35806 - USA Check us out at www.digium.com & www.asterisk.org _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
