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

Bernard Aboba <> Mon, 08 January 2018 06:12 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 31FC5126B6E for <>; Sun, 7 Jan 2018 22:12:52 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2.699
X-Spam-Status: No, score=-2.699 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id XPy5hUXP4riV for <>; Sun, 7 Jan 2018 22:12:50 -0800 (PST)
Received: from ( [IPv6:2607:f8b0:400c:c05::22e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 165A0120454 for <>; Sun, 7 Jan 2018 22:12:50 -0800 (PST)
Received: by with SMTP id l63so6687606vke.5 for <>; Sun, 07 Jan 2018 22:12:50 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=GaSlcrl9VmVPb51R3bhFeHCIZHTn409mWNBu0B0zmaU=; b=gWjdceRKXK9T0pKhpXZjkFd2fDUHKQdGXMPoKbUbKjot+mYDKbL2ofXtOuN4FKX/Kl 4pIenGtGpqBlSSjehZjlueFKZLT/Mb7XVX7DBNQ64RtlRgfWEJpQI6jcpl3MRUX3R60u XdV0zGywMm5o9wuiUmePMm2pmr0u28IF4H3FeFCGm5XFJkKGbgU5EGwTUBMgsgc9b9lp fNJ3NeKIjbs9QJp8HlgcZlWFPCwshq3+ajvedwLMVJPfOVKHiSB9esrXz9somk6XjtQK QM6wMJZyEoRpo+rfihtQ2GwDsJ4YsrHBiDfFues/LBz+9eRxKFLHKDDNpG+YwrTHqRqM wy3g==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=GaSlcrl9VmVPb51R3bhFeHCIZHTn409mWNBu0B0zmaU=; b=luFB2mijD+GmF44XitPRaL2HbHRdb0XE9qWStgzvcqRsCjZfeix6UbEmPZGTe9EuUA HZdYTqoImsYckCh+wPrQildLF6RUbQlzPkBy3KyrCLxtgSLGiZTZ1u8/Aclx3MUUthPu uAucG4rqonCzrDqkoZlYRyFeDAhuaxtwni4hHaKczGKY3d2MFI/gOYpmDaMtbE6ygrfT w3m83V+walVyST/ABtu3sAjkuT4Tp4c7UXESZGhWm0f548u+EMm809MbXEoDZ9bsd+6T NFYWclia8bCReFBmoNgq6C3SV0dQXiHwcEZ6iM+RFsgHl+JA06l7c+rcC3A76rO3QUnS Desg==
X-Gm-Message-State: AKwxytf1R5AyJNMtSEh1/5AlUvpj6nsDjuluw5uRDwNh8XEwij9vxbe5 32MXdxUBRo9rTRKMANs7KlUuTWe3iPAAHSeKSjI=
X-Google-Smtp-Source: ACJfBou+EwnSyWRw2GJ1JRirGKmLFIkpou5sc7/tmajx+3SKKnH75R1CsrT9cCh/LreyqcZM8LBoACl0VGN6XGT3Gp8=
X-Received: by with SMTP id t190mr9815743vka.102.1515391968814; Sun, 07 Jan 2018 22:12:48 -0800 (PST)
MIME-Version: 1.0
Received: by with HTTP; Sun, 7 Jan 2018 22:12:28 -0800 (PST)
In-Reply-To: <p06240601d6785f2e3ad4@>
References: <> <> <> <> <p06240601d6785f2e3ad4@>
From: Bernard Aboba <>
Date: Sun, 7 Jan 2018 22:12:28 -0800
Message-ID: <>
To: Randall Gellens <>
Cc: Eric Rescorla <>, Bernard Aboba <>, "" <>
Content-Type: multipart/alternative; boundary="001a11484ed0ff2c3d05623dafdb"
Archived-At: <>
Subject: Re: [Slim] Eric Rescorla's No Objection on draft-ietf-slim-negotiating-human-language-19: (with COMMENT)
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: Selection of Language for Internet Media <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Mon, 08 Jan 2018 06:12:52 -0000

Randall said:

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

[BA] EKR's question is why it is not sufficient to only advertise
hlang-recv, as is done for codecs.

The "logic" would be to explain the benefits of also advertising

On Sun, Jan 7, 2018 at 5:22 PM, Randall Gellens <>

> At 6:36 AM -0800 1/7/18, Eric Rescorla wrote:
>  On Sat, Jan 6, 2018 at 7:31 PM, Bernard Aboba <<mailto:
>>>> wrote:
>>  On Jan 6, 2018, at 6:55 PM, Eric Rescorla <<>ekr@rtfm
>> .com> 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
> -------------- Randomly selected tag: ---------------
> (If you can't hear me, it's because I'm in parentheses)