Re: [AVTCORE] draft-ietf-avtcore-multi-party-rtt-mix-00 Issue 1: transport Tue, 12 May 2020 02:14 UTC

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To: Gunnar Hellström <>
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Date: Mon, 11 May 2020 22:14:45 -0400
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Subject: Re: [AVTCORE] draft-ietf-avtcore-multi-party-rtt-mix-00 Issue 1: transport
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Speaking to one aspect of one point:

Gunnar Hellstrom <> writes:
> That 
> means real-time transmission while text is created and accepting some 
> rare dropouts just as we do with voice and video. However, users are 
> nowadays used to text messaging where it is customary to accept a delay 
> and get the text complete in most cases, rather than to have loss. That 
> user experience might be expected from real-time text as well.

I was attending IETF meetings around the time that "real-time text"
became an important project, and my understanding is that the
deaf/hard-of-hearing community is very insistent on the real-time nature
of it, as in seeing the pacing of how the sender is typing characters.
In particular, the SIP MESSAGE method, which resembles mobile phone text
messages, was considered quite inadequate.

The possibility of lost packets was compensated for by the RTP
redundancy mechanism.

Poking around, I find,
which points to the Real Time Text Task Force, which has an FAQ containing

    Why is Real-Time Text important to people who are deaf or hard of

    In addition to its many applications for fully hearing people, Real-Time
    Text is important as an equivalent alternative to voice communications
    for people who are deaf and hard of hearing. It allows a more natural,
    bi-directional flow of text based conversation to take place compared
    with the "type-enter-wait-read-response-reply" technology of IM(chat)
    and SMS.

    In fact: when Real-Time Text is fully mainstream, it will be solving one
    of the biggest accessibility problems of Internet communications for
    people who are deaf or hard of hearing!

While searching for that, I found that Verizon has a big page on how to
activate RTT on various phone models