RE: 48-Hour Call for Consensus (CfC): WebRTC Accessibility Considerations

To Janina 

+1 from me. 

Scot. 

Dr Scott Hollier 
Digital Access Specialist 
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-----Original Message-----
From: Janina Sajka (janina@rednote.net) <janina@rednote.net> 
Sent: Wednesday, 16 October 2019 11:16 PM
To: Accessible Platform Architectures Administration <public-apa-admin@w3.org>
Subject: 48-Hour Call for Consensus (CfC): WebRTC Accessibility Considerations

Colleagues:

This is a Call for Consensus (CfC) to the Accessible Platform Architectures (APA) Working Group on a proposed Accessibility Considerations addendum to the WebRTC 1.0 specification:

https://www.w3.org/TR/webrtc/

***Begin Proposed Section
------------------

Accessibility considerations [New section, informative]

The WebRTC 1.0 specification exposes an API to control protocols (defined within the IETF) necessary to establish real-time audio, video and data exchange.

Real-time Text, defined in RFC 4103 on which people who are deaf or hard of hearing (among others) rely on for their communication needs, utilizes T.140 encapsulated in RTP to enable the transition from TDD/TTY devices to IP-based communications. Support for RFC 4103 is especially important as it is being established as the new and more reliable mechanism for text communications with Public Safety Access Points (PSAP).[1]

Since Real-time Text requires the ability to send and receive data in near real time, it can be best supported via the WebRTC 1.0 data channel API. As defined by the IETF, the data channel protocol utilizes the SCTP/DTLS/UDP protocol stack, which supports both reliable and unreliable data channels. The IETF chose to standardize SCTP/DTLS/UDP over proposals for an RTP data channel which relied on SRTP key management and were focused on unreliable communications.

Since the IETF chose a different approach than the RTP data channel as part of the WebRTC suite of protocols, as of the time of this publication there is no standardized way for the WebRTC APIs to directly support Real-time Text as defined at IETF and implemented in U.S. (FCC) regulations.  The WebRTC working Group will evaluate whether the developing IETF protocols in this space warrant direct exposure in the browser APIs and is looking for input from the relevant user communities on this potential gap.

Within the IETF MMUSIC WG, work is ongoing to enable Real-time text to be sent over the WebRTC data channel, allowing gateways to be deployed to translate between the SCTP data channel protocol and RFC 4103 Real-time text. This work, once completed, would enable a unified and interoperable approach for integrating real-time text in WebRTC user-agents (including browsers) - through a gateway or otherwise.

MMUSIC-T140:
https://tools.ietf.org/html/draft-holmberg-mmusic-t140-usage-data-channel

At the time of this publication, gateways that enable effective RTT support in WebRTC clients can be developed e.g. through a custom WebRTC data channel.

This is deemed sufficient until such time as future standardized gateways are enabled via IETF protocols such as the SCTP data channel protocol and RFC 4103 Real-time text. This will need to be defined at IETF in conjunction with related work in W3C groups to effectively and consistently standardise RTT support internationally.

 
[1] https://www.ecfr.gov/cgi-bin/text-idx?SID=ada7cebd65433a9e05c35426a2bc76b8&mc=true&node=pt47.3.67&rgn=div5
------------------

***Action to Take***

This CfC is now open for objection, comment, as well as statements of support via email. Silence will be interpreted as support, though messages of support are certainly welcome.

If you object to this proposed action, or have comments concerning this proposal, please respond by replying on list to this message no later than 23:59 (Midnight) Boston Time, Sunday 20 October.

NOTE: This Call for Consensus is being conducted in accordance with the APA Decision Policy published at:

http://www.w3.org/WAI/APA/decision-policy

Thanks especially to our Research Questions Task Force (RQTF) for working with WebRTC to develop this addendum.

Janina

-- 

Janina Sajka

Linux Foundation Fellow
Executive Chair, Accessibility Workgroup:	http://a11y.org

The World Wide Web Consortium (W3C), Web Accessibility Initiative (WAI)
Chair, Accessible Platform Architectures	http://www.w3.org/wai/apa

Received on Wednesday, 16 October 2019 23:26:35 UTC