> -----Original Message----- > From: Dwight, Timothy M (Tim) > [mailto:[EMAIL PROTECTED] > Sent: Thursday, August 21, 2008 8:37 AM > To: Henry Sinnreich; Dean Willis; Dan Wing > Cc: [email protected]; [EMAIL PROTECTED] > Subject: RE: [Sip] Early media as an endpoint application > > What if you want to implement those or similar services > between VoIP end > systems? For example what if you want to provide "color > ringback tones" > between VoIP end systems? There is no PSTN gateway > involvement in such services.
There are friendlier ways of implementing color ringback tones than described in Brian's document. Brian's document only describes the current state of the art. It would be friendlier, more secure, and allow conveying RTP payload types, to only play media after you have received SDP describing that media. For example, playing color ringback tone could first require sending the caller a 18x with the SDP of the stream generating the color ringback tone (IP address, UDP port, codec, packetization interval, etc.), and then stream the music to the caller. When the called party generates its 18x and SDP, that would also sent to the calling party (who continues playing back the color ringback tone). Sending the called party's SDP allows the calling party to prepare to receive that RTP, such as kicking off DTLS-SRTP (if being used), invoking a transcoder, etc. -- all the while the color ringback tone is being played. When the called party answers, the 200 causes the calling party to prefer that incoming (S)RTP over the color ringback and the color ringback music can be stopped. -d > tim > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > > Behalf Of Henry Sinnreich > > Sent: Thursday, August 21, 2008 10:17 AM > > To: Dean Willis; Dan Wing > > Cc: [email protected]; [EMAIL PROTECTED] > > Subject: [Sip] Early media as an endpoint application > > > > I have changed the Subject title > > > > Early media should just be an endpoint application when the > > SIP endpoint is > > a PSTN gateway. This seems logical, or does it? > > > > =================== > > > > I agree that early media has no role in pure/clean IP-IP > > communications, but > > only when connecting to the PSTN. Should early media support not be > > localized in the respective SIP endpoints, that is in the > > SIP-PSTN gateway? > > > > Support of early media in the SIP-PSTN gateway would resolve > > this issue. > > > > What do you think? > > > > Henry > > > > > > On 8/20/08 5:40 PM, "Dean Willis" <[EMAIL PROTECTED]> wrote: > > > > > > > > On Aug 20, 2008, at 2:22 PM, Dan Wing wrote: > > >> > > >> There are some apparently-legitimate uses of early media, > > > > > > No there aren't, IMHO. > > > > > >> at least > > >> from the perspective of some network operators, to deliver things > > >> like "Than you for using <operator>", advertisements, colorful > > >> ringback > > >> (music as ringback), and so on. Brian did a great > write-up of many > > >> scenarios in the (now expired) > > >> draft-stucker-sipping-early-media-coping-03.txt. > > > > > > Well, if you caveat it that way., then your statement is > > correct. One > > > might reasonably ask if those operators don't simply have their > > > requirements confused. > > > > > > My take, however, is that "early media" is a cop-out for > > coping with a > > > fundamentally broken PSTN-interworking model, coupled > with Bad Ideas > > > about charging based on signaling rather than content. > > > > > > But like forking, this genie has left the bottle, and we > > have to deal > > > with the consequences of that failing as long as we have SIP 2.0. > > > > > > --- > > > Dean > > > > > > _______________________________________________ > > > Sip mailing list https://www.ietf.org/mailman/listinfo/sip > > > This list is for NEW development of the core SIP Protocol > > > Use [EMAIL PROTECTED] for questions on current sip > > > Use [EMAIL PROTECTED] for new developments on the > application of sip > > > > _______________________________________________ > > Sip mailing list https://www.ietf.org/mailman/listinfo/sip > > This list is for NEW development of the core SIP Protocol > > Use [EMAIL PROTECTED] for questions on current sip > > Use [EMAIL PROTECTED] for new developments on the application of sip > > _______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [EMAIL PROTECTED] for questions on current sip Use [EMAIL PROTECTED] for new developments on the application of sip
