<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: Times New Roman; font-size: 12pt; color: #000000'>There needs to be:<div>1) A way of ensuring that media packets being sent to a "UDP URL" are being sent to a cooperating device, which means there must be some sort of handshake which relies on an out-of-band exchange as well. STUN Connectivity Check probes and responses meet this requirement, if it is enforced that this handshake must complete prior to sending media traffic.</div><div>2) A way of describing how these media packets will be encapsulated, especially if audio and video will be on the same UDP port. RTP meets this requirement (if you're ok with using SSRC for multiplexing, for the latter case).</div><div><br></div><div>You do raise the good question as to whether or not peer-to-peer application-level multicast overlays are in scope or not.</div><div><br></div><div>Matthew Kaufman</div><div><br><br><hr><b>From: </b>"Silvia Pfeiffer" <silviapfeiffer1@gmail.com><br><b>To: </b>"Justin Uberti" <juberti@google.com><br><b>Cc: </b>"Stefan Håkansson LK" <stefan.lk.hakansson@ericsson.com>, rtc-web@alvestrand.no, "David Singer" <singer@apple.com>, "Harald Alvestrand" <harald@alvestrand.no><br><b>Sent: </b>Sunday, October 10, 2010 5:44:02 PM<br><b>Subject: </b>Re: [RTW] List is now open<br><br>It seems to me that works nicely for 1-to-1 RTC. It wouldn't even require introduction of RTP/RTSP but can simply be pushing encoded a/v packets over the network as fast as possible on the given URL, which would then be a UDP URL?<br>
<br>I guess for multi-peer RTC a different approach on the network would be required or would it be a full mesh?<br><br>Silvia.<br><br>On Mon, Oct 11, 2010 at 10:43 AM, Justin Uberti <span dir="ltr"><<a href="mailto:juberti@google.com" target="_blank">juberti@google.com</a>></span> wrote:<br>
<div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">My idea is that we will tie these various pieces together like a filter chain, i.e.<div><br>
</div>
<div><device> -> [encoder] -> [transport] -> [decoder] -> <video></div><div><br></div><div>where the connections between pieces are made by passing URLs around. (i.e. opening a device yields a URL for a stream, which is supplied to the encoder; at the other end, streams coming from the decoder are identified by a URL, which can then be passed directly to a <video> tag or WebGL texture.)</div>
<div><br></div><div>Other combinations are of course possible, such as direct access to [transport], in the case of a web real-time game, or combining <device> -> encoder -> websocket, for doing live (non-realtime) broadcasts.</div>
<div><br></div><div>We're still figuring out the right interfaces for encoder/decoder; for transport, hopefully the <a href="https://docs.google.com/viewer?url=http://rtc-web.alvestrand.com/papers/juberti-p2ptransport-api.pdf%3Fattredirects%3D0" target="_blank">draft I proposed</a> can serve as a reasonable starting point.</div>
<div><br></div><div><font color="#888888">--justin</font><div><div></div><div class="h5"><br><br><div class="gmail_quote">On Sun, Oct 10, 2010 at 4:26 PM, Stefan Håkansson LK <span dir="ltr"><<a href="mailto:stefan.lk.hakansson@ericsson.com" target="_blank">stefan.lk.hakansson@ericsson.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">That's right, a lot of things remain regarding protocols
and other stuff. But IMHO <device>, StreamAPIs and <audio> and
<video> should be part of the puzzle! </font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">--Stefan</font></span></div><br>
<div dir="ltr" align="left" lang="en-us">
<hr>
<font face="Tahoma" size="2"><b>From:</b> Silvia Pfeiffer
[mailto:<a href="mailto:silviapfeiffer1@gmail.com" target="_blank">silviapfeiffer1@gmail.com</a>] <br><b>Sent:</b> den 11 oktober 2010
01:23<br><b>To:</b> Stefan Håkansson LK<br><b>Cc:</b> Harald Alvestrand;
<a href="mailto:rtc-web@alvestrand.no" target="_blank">rtc-web@alvestrand.no</a>; David Singer<div><div></div><div><br><b>Subject:</b> Re: [RTW] List is now
open<br></div></div></font><br></div><div><div></div><div>
<div></div>Hi Stefan,<br><br>I have seen those, thanks. That's actually the
reason why I asked: because I have already seen it work with the <device>
element and I wondered what the remaining challenges were. It seems there is
lots of discussion about protocols and
codecs.<br><br>Cheers,<br>Silvia.<br><br><br>
<div class="gmail_quote">On Mon, Oct 11, 2010 at 9:49 AM, Stefan Håkansson LK
<span dir="ltr"><<a href="mailto:stefan.lk.hakansson@ericsson.com" target="_blank">stefan.lk.hakansson@ericsson.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="padding-left:1ex;margin:0px 0px 0px 0.8ex;border-left:#ccc 1px solid">
<div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">Silvia,</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">you might
be interested in some experimenting we've done with media streams and
<device>: <a href="https://labs.ericsson.com/developer-community/blog/beyond-html5-conversational-voice-and-video-implemented-webkit-gtk" target="_blank"><font face="Times New Roman" size="3">https://labs.ericsson.com/developer-community/blog/beyond-html5-conversational-voice-and-video-implemented-webkit-gtk</font></a> (you
can track back to earlier posts).</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">BR,</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" face="Arial" size="2">Stefan</font></span></div><br>
<div dir="ltr" align="left" lang="en-us">
<hr>
<font face="Tahoma" size="2"><b>From:</b> <a href="mailto:rtc-web-bounces@alvestrand.no" target="_blank">rtc-web-bounces@alvestrand.no</a> [mailto:<a href="mailto:rtc-web-bounces@alvestrand.no" target="_blank">rtc-web-bounces@alvestrand.no</a>] <b>On Behalf Of </b>Harald
Alvestrand<br><b>Sent:</b> den 9 oktober 2010 10:12<br><b>To:</b> Silvia
Pfeiffer<br><b>Cc:</b> <a href="mailto:rtc-web@alvestrand.no" target="_blank">rtc-web@alvestrand.no</a>; David Singer<br><b>Subject:</b> Re:
[RTW] List is now open<br></font><br></div>
<div>
<div></div>
<div>
<div></div>On 10/09/10 03:17, Silvia Pfeiffer wrote:
<blockquote>Thanks for the general invite!<br><br>I wonder: has
the HTML5 device element been looked at (<a href="http://dev.w3.org/html5/html-device/" target="_blank">http://dev.w3.org/html5/html-device/</a>) and what are the
problems with that solution?<br></blockquote>We're the ones who have to look -
and some on the list have been closely involved with writing the
<device> spec. It would be surprising to me if they are not part of the
solution - but just part.<br><br>As far as I know, it's still not clear how to
tie a <device> to a media stream - given that media streams aren't
defined yet, this is not very surprising :-)<br><br>
<blockquote><br>Cheers,<br>Silvia.<br><br><br>
<div class="gmail_quote">On Sat, Oct 9, 2010 at 5:28 PM, David Singer <span dir="ltr"><<a href="mailto:singer@apple.com" target="_blank">singer@apple.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="padding-left:1ex;margin:0pt 0pt 0pt 0.8ex;border-left:rgb(204,204,204) 1px solid">Cool,
thanks Harald<br><br>as I said during the day, I'd like to separate (as
much as possible) "why is real-time communications on the internet hard?"
(which is true, but a subject the IETF, the ITU, and others are also
grappling with) from "what is interesting/challenging about real-time
communications *in the web*?" -- which I take to mean in pages shown by a
browser.<br><br><br>On Oct 8, 2010, at 4:24 , Harald Alvestrand
wrote:<br><br>> Cullen (I think) has changed the permissions on the
list, so that now everyone can subscribe, and the archives are
open.<br>><br>> If you know of people you think should be on the
list, please ask them to subscribe!<br>><br>> The two ways to
subscribe:<br>><br>> - Send "subscribe" to <a href="mailto:rtc-web-request@alvestrand.no" target="_blank">rtc-web-request@alvestrand.no</a>, and do what the response
says<br>> - Go to <a href="http://www.alvestrand.no/mailman/listinfo/rtc-web" target="_blank">http://www.alvestrand.no/mailman/listinfo/rtc-web</a> and
follow instructions<br>><br>> Let the discussions
begin!<br>><br>>
Harald<br>><br>>
_______________________________________________<br>> RTC-Web mailing
list<br>> <a href="mailto:RTC-Web@alvestrand.no" target="_blank">RTC-Web@alvestrand.no</a><br>> <a href="http://www.alvestrand.no/mailman/listinfo/rtc-web" target="_blank">http://www.alvestrand.no/mailman/listinfo/rtc-web</a><br>
<br>David
Singer<br>Multimedia and Software Standards, Apple
Inc.<br><br>_______________________________________________<br>RTC-Web
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</blockquote></div><br></blockquote><br></div></div></div></blockquote></div><br></div></div></div>
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