Re: [rtcweb] Summary of Application Developers' opinions of the current WebRTC API and SDP as a control surface

"mindless works fist"?  There's a deep meaning there, but I'm still trying
to figure it out...


On Fri, Jul 19, 2013 at 7:04 AM, Cullen Jennings <fluffy@iii.ca> wrote:

> Folks wanted to sort out how mindless works fist before getting to theses
> smaller details but in general I think progress is being made on all of
> these
>
> On Jul 17, 2013, at 2:58 PM, "Matthew Kaufman (SKYPE)" <
> matthew.kaufman@skype.net> wrote:
>
> > Bernard Aboba:
> >>
> >> The problem was that we never defined what mangling browsers had to
> >> support. Given all the SDP specs that is actually a huge work item.
> >
> >
> > This is exactly what my slides that weren't presented last November
> started to touch upon. It only takes a few minutes with RFC3264 and its
> references to start documenting cases that are clearly "valid SDP
> offer/answer" and yet for which I cannot for the life of me figure out what
> a browser should do if they're presented.
> >
> > Just off the top of my head:
> >
> > Can I...
> > - Change the t= line to be something other than t=0 0?
> > - Change the rtpmap associations before calling setLocal?
> > - Change a=sendrecv to a=recvonly before calling setLocal?
> > - What do you do when you see a=content:sl ?
> > - What if someone adds an r= or p= or e=?
> > - What is the RFC that describes a=group:BUNDLE (as seen in some browser
> implementations)?
> > - Can I remove a=group:BUNDLE (or add it) before calling setLocal?
> > - How about removing a=rtcp-mux?
> > - Should I do something special at my end if you set
> a=ice-options:google-ice ?
> > - If you put a=ssrc lines in there, can I change the ssrc before passing
> it back to setLocal?
> > - Can I delete the a=ssrc lines?
> > - Is a=rtcp:1 IN IP4 0.0.0.0 valid or not?
> > - What about 0.0.0.0 in the o= line?
> > - If I get a bunch of a=candidate lines, can I swap them around to
> change the priority before calling setLocal?
> > - What if someone claims SAVP instead of SAVPF but gives me rtcp info?
> >
> > At the *very least* for each and every line that comes from createOffer
> and createAnswer you must be able to answer the following:
> > - Can I delete it?
> > - Duplicate it?
> > - Change it?
> > - If not, how are violation handled? (Both when passed to another
> browser at the far end and when these modifications happen before calling
> setLocal)
> > - And can I add additional valid SDP to what came from createOffer or
> createAnswer and pass it back to setLocal or not?
> >
> > We appear to be nowhere near a document which explains the answers to
> these questions, certainly not in the W3C WG, and not in any IETF RFC or
> draft I can locate.
> >
> > Matthew Kaufman
> >
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> > rtcweb@ietf.org
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