Re: [rtcweb] Meaning of SHOULD support/use interleaving
Paul Kyzivat <pkyzivat@alum.mit.edu> Tue, 28 October 2014 22:14 UTC
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Date: Tue, 28 Oct 2014 18:14:19 -0400
From: Paul Kyzivat <pkyzivat@alum.mit.edu>
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Subject: Re: [rtcweb] Meaning of SHOULD support/use interleaving
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Mary pointed out an important typo in this message. Correction inline. On 10/28/14 4:13 PM, Paul Kyzivat wrote: > (This thread has gotten long, and its hard to figure where to jump in. > I'm just replying to the last message I see, but am commenting on the > thread in total.) > > Regarding data channels being webrtc-specific: > > I don't see it that way. Webrtc has opened up restricted communication > among browsers. If you want to talk to a browser, you have few choices, > and this is the one that is "general purpose". So any application that > sometimes might need to run in a browser is a likely candidate for data > channels. And then, when non-browser versions of that app are talking to > one another, it will be most practical to use the same mechanism. > > That is why CLUE is using data channels - even if we think that *most* > of the endpoints won't be in browsers. > > Regarding NDATA: > > ISTM that SCTP just screwed up in not including the NDATA features in > the base protocol. Going forward, it always should be included in new > implementations. Since data channels are being defined after NDATA, it > is perfectly reasonable for data channels to require NDATA support. > > IIUC, while NDATA allows fragmentation to avoid head of line blocking, > that doesn't mean the messages will be fragmented unnecessarily. If you > are only using one channel I *think* it likely that even a large message > won't be fragmented. So it will be harmless insurance. > > Christer said that since CLUE only needs one data channel there is no > need for NDATA. Someone specifying BFCP over data channel might reach a > similar conclusion for it. But there is nothing to prevent an > application that implements both CLUE and BFCP. Independently they > wouldn't need NDATA, but together they would. > > So I am in favor of making NDATA mandatory to implement, offer, and > accept for data channels. > > But I would still like the data channel spec to acknowledge that, while > webrtc is a *very* important client, that the protocol solely for > webrtc. And with that in mind I would like to see "webrtc" removed from > the name of the protocol. (E.g., in the SDP m-line.) What I meant to say in the last paragraph is: But I would still like the data channel spec to acknowledge that, while webrtc is a *very* important client, that the protocol *is not* solely for webrtc. And with that in mind I would like to see "webrtc" removed from the name of the protocol. (E.g., in the SDP m-line.) Thanks, Paul > On 10/28/14 1:53 PM, Christer Holmberg wrote: >> Hi, >> >> >>> I am not suggesting different flavors - I am suggesting to make >> the usage of >> >>> interleaving optional. Other SCTP features are also optional >> (including reliability, ordering etc). >> >>> >> >>> Where are these things optional? According to >> >>> >> https://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-12#section >> >>> -6.1 an implementation MUST implement PR-SCTP and the support >> of the >> >>> FORWARD-TSN chunk will be negotiated similar to the NDATA >> chunk. I don't see a difference, especially not if we move to MUST >> support NDATA. >> >> >> >> For example, section 6.1 says: >> >> >> >> "The partial reliability extension defined in [RFC3758] >> MUST be supported." >> >> >> >> However, in CLUE we say that a CLUE entity MUST NOT *use* the >> extension, as all CLUE messages are required to be sent reliably. >> > >> > That is OK. However, support for PR-SCTP MUST be there and it >> will be negotiated. You just never send a message with partial >> reliability. At least this is my understanding... >> >> So, can the same be done for interleaving? I.e. the support MUST be >> there, but e.g. CLUE entities can choose not to use it? >> >> Note that my issue is not about support, it's about usage :) >> >> What resource is being conserved by not just requiring it? >> >> I don’t know. The task is to figure out whether there are *technical* >> reasons to mandate usage of certain SCTP features for CLUE. >> >> Regards, >> >> Christer >> >> >> >> _______________________________________________ >> rtcweb mailing list >> rtcweb@ietf.org >> https://www.ietf.org/mailman/listinfo/rtcweb >> > > _______________________________________________ > rtcweb mailing list > rtcweb@ietf.org > https://www.ietf.org/mailman/listinfo/rtcweb >
- [rtcweb] Meaning of SHOULD support/use interleavi… Christer Holmberg
- Re: [rtcweb] Meaning of SHOULD support/use interl… Michael Tuexen
- Re: [rtcweb] Meaning of SHOULD support/use interl… Christer Holmberg
- Re: [rtcweb] Meaning of SHOULD support/use interl… Harald Alvestrand
- Re: [rtcweb] Meaning of SHOULD support/use interl… Christer Holmberg
- Re: [rtcweb] Meaning of SHOULD support/use interl… Michael Tuexen
- Re: [rtcweb] Meaning of SHOULD support/use interl… Michael Tuexen
- Re: [rtcweb] Meaning of SHOULD support/use interl… Michael Tuexen
- Re: [rtcweb] Meaning of SHOULD support/use interl… Harald Alvestrand
- Re: [rtcweb] Meaning of SHOULD support/use interl… Christer Holmberg
- Re: [rtcweb] Meaning of SHOULD support/use interl… Michael Tuexen
- Re: [rtcweb] Meaning of SHOULD support/use interl… Christer Holmberg
- Re: [rtcweb] Meaning of SHOULD support/use interl… Makaraju, Maridi Raju (Raju)
- Re: [rtcweb] Meaning of SHOULD support/use interl… Michael Tuexen
- Re: [rtcweb] Meaning of SHOULD support/use interl… Harald Alvestrand
- Re: [rtcweb] Meaning of SHOULD support/use interl… Martin Thomson
- Re: [rtcweb] Meaning of SHOULD support/use interl… Eric Rescorla
- Re: [rtcweb] Meaning of SHOULD support/use interl… Justin Uberti
- Re: [rtcweb] Meaning of SHOULD support/use interl… Christer Holmberg
- Re: [rtcweb] Meaning of SHOULD support/use interl… Makaraju, Maridi Raju (Raju)
- Re: [rtcweb] Meaning of SHOULD support/use interl… Makaraju, Maridi Raju (Raju)
- Re: [rtcweb] Meaning of SHOULD support/use interl… Harald Alvestrand
- Re: [rtcweb] Meaning of SHOULD support/use interl… Christer Holmberg
- Re: [rtcweb] Meaning of SHOULD support/use interl… Michael Tuexen
- Re: [rtcweb] Meaning of SHOULD support/use interl… Christer Holmberg
- Re: [rtcweb] Meaning of SHOULD support/use interl… Eric Rescorla
- Re: [rtcweb] Meaning of SHOULD support/use interl… Makaraju, Maridi Raju (Raju)
- Re: [rtcweb] Meaning of SHOULD support/use interl… Christer Holmberg
- Re: [rtcweb] Meaning of SHOULD support/use interl… Paul Kyzivat
- Re: [rtcweb] Meaning of SHOULD support/use interl… Mo Zanaty (mzanaty)
- Re: [rtcweb] Meaning of SHOULD support/use interl… Michael Tuexen
- Re: [rtcweb] Meaning of SHOULD support/use interl… Paul Kyzivat
- Re: [rtcweb] Meaning of SHOULD support/use interl… Mo Zanaty (mzanaty)
- Re: [rtcweb] Meaning of SHOULD support/use interl… Christian Groves
- Re: [rtcweb] Meaning of SHOULD support/use interl… Makaraju, Maridi Raju (Raju)
- Re: [rtcweb] Meaning of SHOULD support/use interl… Mo Zanaty (mzanaty)
- Re: [rtcweb] Meaning of SHOULD support/use interl… Michael Tuexen
- Re: [rtcweb] Meaning of SHOULD support/use interl… Mo Zanaty (mzanaty)
- Re: [rtcweb] Meaning of SHOULD support/use interl… Michael Tuexen
- Re: [rtcweb] Meaning of SHOULD support/use interl… Michael Tuexen
- Re: [rtcweb] Meaning of SHOULD support/use interl… Mo Zanaty (mzanaty)