Re: [Slim] Eric Rescorla's No Objection on draft-ietf-slim-negotiating-human-language-19: (with COMMENT)

[Randall Gellens <[e-mail]>]

At 6:36 AM -0800 1/7/18, Eric Rescorla wrote:

>  On Sat, Jan 6, 2018 at 7:31 PM, Bernard Aboba 
> <<mailto:[e-mail]>[e-mail]> wrote:
>
>  On Jan 6, 2018, at 6:55 PM, Eric Rescorla 
> <<mailto:[e-mail]>[e-mail]> wrote:
>
>>  For disabled users, the capabilities may not be symmetric.
>>
>
>  But this is true for ordinary SDP as well. I might be able to 
> receive H.264 but not send it.
>
>
>  [BA] Thanks. The draft should explain the reasoning. IMHO the 
> argument goes sonething like this:
>
>  A pure recv/recv negotiation will not necessarily disclose 
> beforehand what special services are needed for the call - services 
> (e.g. ASL interpretation or RTT handling) that could take time to 
> acquire.
>
>  Since the actual video media sent is not labelled as ASL even if 
> the answerer has ASL interpreters it can pull in and therefore 
> advertises in SDP ASL reception capability in video, a recv/recv 
> negotiation doesn't tell the Answerer that the Offerer will need 
> them, so the Answerer may need to (frantically) arrange for ASL 
> interpretation after initial receipt of media. In an emergency, 
> that can chew up valuable time.
>
>
>  Thanks. I think it would be helpful to put this logic in the draft.

I am not clear on what logic we want to add to the draft, or what 
about the draft this logic is explaining.

>  That said, as I noted in my review, it is still possible to get 
> some media (early media) prior to receiving the answer, so this 
> isn't a complete solution.

The draft provides a useful mechanism that will be helpful.  As an 
example of the fact that others find it useful, NENA has included it 
in it's next-generation emergency call architecture standards.  The 
draft does not try to solve all problems related to human language in 
real-time calling.

-- 
Randall Gellens
Opinions are personal;    facts are suspect;    I speak for myself only
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