Re: [rtcweb] Comments on draft-ietf-rtcweb-data-channel-07

[Barry Dingle <[e-mail]>]

On Tue, Feb 25, 2014 at 9:58 PM, Magnus Westerlund <
[e-mail]> wrote:

> On 2014-02-23 10:54, Barry Dingle wrote:
> > In reference to your first _Section 1 comments_, I agree that we need to
> > clearly differentiate the SRTP media and the SCTP media. (Note - SRTP -
> > not RTP !)
>
> So SRTP is an extension of RTP, in fact it is a profile, or rather two
> (RTP/SAVP or RTP/SAVPF). I wrote RTP because I meant no specific RTP
> configuration here, it can be any of the profiles and any of the
> extensions. I know and fully support that RTCWEB uses RTP/SAVPF for RTP
> transported media, however in the wider context and possible other usage
> of the defined mechanism this may or may not be true. Therefore I see a
> need to be generic in that discussion. If one want to emphasize the SRTP
> part, then use (S)RTP.
>
> I see your point about being generic - and it is consistent with
draft-ietf-rtcweb-rtp-usage.


 >
> > I agree that there could be real-time media that can be sent over SCTP
> > Channels are still meet the criteria for 'real-time' as being 'received
> > within a few hundred milliseconds of being generated' - see WebRTC
> > Overview section 2.4.
> >
> > Maybe we need to differentiate the Channel types - and then refer to the
> > data going over those Channels. For instance,if we define "SRTP
> > Channels" and "SCTP Channels", we could then refer to 'SRTP Channel
> > media' which would have a specific meaning.
>
> Well, around RTP we aren't discussing "channels" at all. Thus, this
> becomes very ambiguous to what it means, unless you have a definition to
> go along with it.
>
> In the context of a PeerConnection we can have one or more RTP session.
>
> Also, I don't know what an SCTP channel is. There is an SCTP
> association, which is something between two endpoints. On top of this we
> have the SCTP Data channels. So what are you missing or want from these
> definitions?
>
> I was trying to find a way to identify
(a) 'all the SCTP Streams' (or maybe "all the SCTP Channels") as well as
(b) "all the (S)RTP Streams".

As you suggested, the term "SCTP Association" seems to work for (a). Does
"RTP Session" work for (b) ??

Cheers,
/Barry Dingle

>
> Cheers
>
> Magnus Westerlund
>
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