WebRTC Ingest Signaling over HTTPS
charter-ietf-wish-01

The WISH working group is chartered to specify a simple, extensible,
HTTPS-based signaling protocol to establish one-way WebRTC-based audiovisual
sessions between broadcasting tools and real-time media broadcast networks.

Background:

WebRTC defines a set of wire protocols for real-time media transmission, as
well as a profile of the Session Description Protocol (SDP) for setting up and
controlling the associated media streams. Because of its typical use cases, and
to increase overall flexibility, WebRTC did not specify a wire protocol for
exchanging SDP messages, leaving the creation of such protocols up to the
applications that use WebRTC. This works well when WebRTC clients are
vertically integrated with the servers they communicate with, as it allows for
rapid iteration of new features.

At the same time, the use of WebRTC as a mechanism for large-scale media
broadcast is gaining popularity, with companies such as Millicast, Caffeine,
Janus/Meetecho, Evercast, Wowza, Liveswitch, Antmedia, and Strivecast deploying
WebRTC-based media distribution networks. Unlike more vertically integrated
uses of WebRTC, these networks would benefit immensely from being able to
re-use the several broadcasting tools that have been developed over time (such
as Wirecast, OBS, Stretchcast, NewBlue Stream, XSplit, FFSplit, Lightstream,
vMix, and a host of other applications). To date, these media distribution
networks have employed their own proprietary signaling protocols to establish
the connection between broadcasting tools and the network, generally requiring
either bespoke software or customized modifications to existing broadcasting
tools.

With the large number of available tools and the growing number of real-time
media distribution networks, this ad-hoc approach to creating custom protocols
for establishing sessions clearly does not scale. The real-time broadcasting
ecosystem would benefit immensely from a single, shared protocol to meet this
goal.

Deliverables:

The product of this working group will be a specification for a simple,
extensible, HTTPS-based signaling protocol to establish one-way WebRTC-based
audiovisual sessions between broadcasting tools and real-time media broadcast
networks.

This working group will use existing HTTPS, WebRTC, and SDP mechanisms to the
extent possible. While no extensions to those core protocols is expected, the
working group may consider such extensions if they are necessary to meet the
requirements of broadcasting tools and networks. Any such work will be
coordinated with the HTTPBIS, MMUSIC, and/or MOPS working groups, as
appropriate.  Additionally, this working group will coordinate with HTTPBIS and
HTTPAPI to assure that the HTTP protocol is being used according to current
best practice.

While there may be other problems that the proposed mechanism may solve or
nearly solve, such as video display clients connecting to the egress of a media
delivery network, adding explicit protocol support for those use cases is not
in scope for the WISH working group.