Internet DRAFT - draft-ietf-wish-whip
draft-ietf-wish-whip
wish S. Murillo
Internet-Draft Millicast
Updates: 8842, 8840 (if approved) A. Gouaillard
Intended status: Standards Track CoSMo Software
Expires: 10 August 2024 7 February 2024
WebRTC-HTTP ingestion protocol (WHIP)
draft-ietf-wish-whip-13
Abstract
This document describes a simple HTTP-based protocol that will allow
WebRTC-based ingestion of content into streaming services and/or
CDNs.
This document updates RFC 8842 and RFC 8840.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 10 August 2024.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Murillo & Gouaillard Expires 10 August 2024 [Page 1]
Internet-Draft whip February 2024
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Protocol Operation . . . . . . . . . . . . . . . . . . . . . 5
4.1. ICE support . . . . . . . . . . . . . . . . . . . . . . . 8
4.1.1. HTTP PATCH request usage . . . . . . . . . . . . . . 9
4.1.2. Trickle ICE . . . . . . . . . . . . . . . . . . . . . 9
4.1.3. ICE Restarts . . . . . . . . . . . . . . . . . . . . 11
4.2. WebRTC constraints . . . . . . . . . . . . . . . . . . . 14
4.2.1. SDP Bundle . . . . . . . . . . . . . . . . . . . . . 14
4.2.2. Single MediaStream . . . . . . . . . . . . . . . . . 14
4.2.3. No partially successful answers . . . . . . . . . . . 14
4.2.4. DTLS setup role and SDP "setup" attribute . . . . . . 14
4.2.5. Trickle ICE and ICE restarts . . . . . . . . . . . . 15
4.3. Load balancing and redirections . . . . . . . . . . . . . 15
4.4. STUN/TURN server configuration . . . . . . . . . . . . . 15
4.5. Authentication and authorization . . . . . . . . . . . . 17
4.5.1. Bearer token authentication . . . . . . . . . . . . . 17
4.6. Simulcast and scalable video coding . . . . . . . . . . . 18
4.7. Protocol extensions . . . . . . . . . . . . . . . . . . . 18
5. Security Considerations . . . . . . . . . . . . . . . . . . . 19
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
6.1. Link Relation Type: ice-server . . . . . . . . . . . . . 20
6.2. Registration of WHIP URN Sub-namespace and WHIP
Registry . . . . . . . . . . . . . . . . . . . . . . . . 21
6.3. URN Sub-namespace for WHIP . . . . . . . . . . . . . . . 21
6.3.1. Specification Template . . . . . . . . . . . . . . . 21
6.4. Registering WHIP Protocol Extensions URNs . . . . . . . . 23
6.4.1. Registration Procedure . . . . . . . . . . . . . . . 23
6.4.2. Guidance for Designated Experts . . . . . . . . . . . 24
6.4.3. WHIP Protocol Extension Registration Template . . . . 25
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 25
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 25
8.1. Normative References . . . . . . . . . . . . . . . . . . 25
8.2. Informative References . . . . . . . . . . . . . . . . . 30
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 30
1. Introduction
The IETF RTCWEB working group standardized JSEP ([RFC8829]), a
mechanism used to control the setup, management, and teardown of a
multimedia session. It also describes how to negotiate media flows
using the Offer/Answer Model with the Session Description Protocol
(SDP) [RFC3264] including the formats for data sent over the wire
(e.g., media types, codec parameters, and encryption). WebRTC
intentionally does not specify a signaling transport protocol at
Murillo & Gouaillard Expires 10 August 2024 [Page 2]
Internet-Draft whip February 2024
application level.
Unfortunately, the lack of a standardized signaling mechanism in
WebRTC has been an obstacle to adoption as an ingestion protocol
within the broadcast/streaming industry, where a streamlined
production pipeline is taken for granted: plug in cables carrying raw
media to hardware encoders, then push the encoded media to any
streaming service or Content Delivery Network (CDN) ingest using an
ingestion protocol.
While WebRTC can be integrated with standard signaling protocols like
SIP [RFC3261] or XMPP [RFC6120], they are not designed to be used in
broadcasting/streaming services, and there is also no sign of
adoption in that industry. RTSP [RFC7826], which is based on RTP,
does not support the SDP offer/answer model [RFC3264] for negotiating
the characteristics of the media session.
This document proposes a simple protocol based on HTTP for supporting
WebRTC as media ingestion method which:
* Is easy to implement,
* Is as easy to use as popular IP-based broadcast protocols
* Is fully compliant with WebRTC and RTCWEB specs
* Enables ingestion on both traditional media platforms and WebRTC
end-to-end platforms, achieving the lowest possible latency.
* Lowers the requirements on both hardware encoders and broadcasting
services to support WebRTC.
* Is usable both in web browsers and in standalone encoders.
2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
Murillo & Gouaillard Expires 10 August 2024 [Page 3]
Internet-Draft whip February 2024
3. Overview
The WebRTC-HTTP Ingest Protocol (WHIP) is designed to facilitate a
one-time exchange of Session Description Protocol (SDP) offers and
answers using HTTP POST requests. This exchange is a fundamental
step in establishing an Interactive Connectivity Establishment (ICE)
and Datagram Transport Layer Security (DTLS) session between the WHIP
client, which represents the encoder or media producer, and the media
server, the broadcasting ingestion endpoint.
Upon successful establishment of the ICE/DTLS session, unidirectional
media data transmission commences from the WHIP client to the media
server. It is important to note that SDP renegotiations are not
supported in WHIP, meaning that no modifications to the "m=" sections
can be made after the initial SDP offer/answer exchange via HTTP POST
is completed and only ICE related information can be updated via HTTP
PATCH requests as defined in Section 4.1.
The following diagram illustrates the core operation of the WHIP
protocol for initiating and terminating an ingest session:
+-------------+ +---------------+ +--------------+ +---------------+
| WHIP client | | WHIP endpoint | | Media Server | | WHIP session |
+--+----------+ +---------+-----+ +------+-------+ +--------|------+
| | | |
| | | |
|HTTP POST (SDP Offer) | | |
+------------------------>+ | |
|201 Created (SDP answer) | | |
+<------------------------+ | |
| ICE REQUEST | |
+--------------------------------------->+ |
| ICE RESPONSE | |
|<---------------------------------------+ |
| DTLS SETUP | |
|<======================================>| |
| RTP/RTCP FLOW | |
+<-------------------------------------->+ |
| HTTP DELETE |
+---------------------------------------------------------->+
| 200 OK |
<-----------------------------------------------------------x
Figure 1: WHIP session setup and teardown
The elements in Figure 1 are described as follows:
Murillo & Gouaillard Expires 10 August 2024 [Page 4]
Internet-Draft whip February 2024
* WHIP client: This represents the WebRTC media encoder or producer,
which functions as a client of the WHIP protocol by encoding and
delivering media to a remote media server.
* WHIP endpoint: This denotes the ingest server that receives the
initial WHIP request.
* WHIP endpoint URL: Refers to the URL of the WHIP endpoint
responsible for creating the WHIP session.
* media server: This is the WebRTC media server or consumer
responsible for establishing the media session with the WHIP
client and receiving the media content it produces.
* WHIP session: Indicates the allocated HTTP resource by the WHIP
endpoint for handling an ongoing ingest session.
* WHIP session URL: Refers to the URL of the WHIP resource allocated
by the WHIP endpoint for a specific media session. The WHIP
client can send requests to the WHIP session using this URL to
modify the session, such as ICE operations or termination.
4. Protocol Operation
In order to set up an ingestion session, the WHIP client MUST
generate an SDP offer according to the JSEP rules for an initial
offer as in Section 5.2.1 of [RFC8829] and perform an HTTP POST
request as per Section 9.3.3 of [RFC9110] to the configured WHIP
endpoint URL.
The HTTP POST request MUST have a content type of "application/sdp"
and contain the SDP offer as the body. The WHIP endpoint MUST
generate an SDP answer according to the JSEP rules for an initial
answer as in Section 5.3.1 of [RFC8829] and return a "201 Created"
response with a content type of "application/sdp", the SDP answer as
the body, and a Location header field pointing to the newly created
WHIP session.
As the WHIP protocol only supports the ingestion use case with
unidirectional media, the WHIP client SHOULD use "sendonly" attribute
in the SDP offer but MAY use the "sendrecv" attribute instead,
"inactive" and "recvonly" attributes MUST NOT be used. The WHIP
endpoint MUST use "recvonly" attribute in the SDP answer.
Murillo & Gouaillard Expires 10 August 2024 [Page 5]
Internet-Draft whip February 2024
If the HTTP POST to the WHIP endpoint has a content type different
than "application/sdp", the WHIP endpoint MUST reject the HTTP POST
request with a "415 Unsupported Media Type" error response. If the
SDP body is malformed, the WHIP session MUST reject the HTTP POST
with a "400 Bad Request" error response.
Following is an example of an HTTP POST sent from a WHIP client to a
WHIP endpoint and the "201 Created" response from the WHIP endpoint
containing the Location header pointing to the newly created WHIP
session:
POST /whip/endpoint HTTP/1.1
Host: whip.example.com
Content-Type: application/sdp
Content-Length: 1101
v=0
o=- 5228595038118931041 2 IN IP4 127.0.0.1
s=-
t=0 0
a=group:BUNDLE 0 1
a=extmap-allow-mixed
a=ice-options:trickle ice2
m=audio 9 UDP/TLS/RTP/SAVPF 111
c=IN IP4 0.0.0.0
a=rtcp:9 IN IP4 0.0.0.0
a=ice-ufrag:EsAw
a=ice-pwd:bP+XJMM09aR8AiX1jdukzR6Y
a=fingerprint:sha-256 DA:7B:57:DC:28:CE:04:4F:31:79:85:C4:31:67:EB:27:58:29:ED:77:2A:0D:24:AE:ED:AD:30:BC:BD:F1:9C:02
a=setup:actpass
a=mid:0
a=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid
a=sendonly
a=msid:d46fb922-d52a-4e9c-aa87-444eadc1521b ce326ecf-a081-453a-8f9f-0605d5ef4128
a=rtcp-mux
a=rtcp-mux-only
a=rtpmap:111 opus/48000/2
a=fmtp:111 minptime=10;useinbandfec=1
m=video 0 UDP/TLS/RTP/SAVPF 96 97
a=mid:1
a=bundle-only
a=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid
a=extmap:10 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id
a=extmap:11 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id
a=sendonly
a=msid:d46fb922-d52a-4e9c-aa87-444eadc1521b 3956b460-40f4-4d05-acef-03abcdd8c6fd
a=rtpmap:96 VP8/90000
a=rtcp-fb:96 ccm fir
Murillo & Gouaillard Expires 10 August 2024 [Page 6]
Internet-Draft whip February 2024
a=rtcp-fb:96 nack
a=rtcp-fb:96 nack pli
a=rtpmap:97 rtx/90000
a=fmtp:97 apt=96
HTTP/1.1 201 Created
ETag: "xyzzy"
Content-Type: application/sdp
Content-Length: 1053
Location: https://whip.example.com/session/id
v=0
o=- 1657793490019 1 IN IP4 127.0.0.1
s=-
t=0 0
a=group:BUNDLE 0 1
a=extmap-allow-mixed
a=ice-lite
a=ice-options:trickle ice2
m=audio 9 UDP/TLS/RTP/SAVPF 111
c=IN IP4 0.0.0.0
a=rtcp:9 IN IP4 0.0.0.0
a=ice-ufrag:38sdf4fdsf54
a=ice-pwd:2e13dde17c1cb009202f627fab90cbec358d766d049c9697
a=fingerprint:sha-256 F7:EB:F3:3E:AC:D2:EA:A7:C1:EC:79:D9:B3:8A:35:DA:70:86:4F:46:D9:2D:CC:D0:BC:81:9F:67:EF:34:2E:BD
a=candidate:1 1 UDP 2130706431 198.51.100.1 39132 typ host
a=setup:passive
a=mid:0
a=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid
a=recvonly
a=rtcp-mux
a=rtcp-mux-only
a=rtpmap:111 opus/48000/2
a=fmtp:111 minptime=10;useinbandfec=1
m=video 0 UDP/TLS/RTP/SAVPF 96 97
c=IN IP4 0.0.0.0
a=mid:1
a=bundle-only
a=extmap:4 urn:ietf:params:rtp-hdrext:sdes:mid
a=extmap:10 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id
a=extmap:11 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id
a=recvonly
a=rtpmap:96 VP8/90000
a=rtcp-fb:96 ccm fir
a=rtcp-fb:96 nack
a=rtcp-fb:96 nack pli
a=rtpmap:97 rtx/90000
a=fmtp:97 apt=96
Murillo & Gouaillard Expires 10 August 2024 [Page 7]
Internet-Draft whip February 2024
Figure 2: Example of SDP offer/answer exchange done via an HTTP POST
Once a session is setup, consent freshness as per [RFC7675] SHALL be
used to detect non-graceful disconnection by full ICE implementations
and DTLS teardown for session termination by either side.
To explicitly terminate a WHIP session, the WHIP client MUST perform
an HTTP DELETE request to the WHIP session URL returned in the
Location header field of the initial HTTP POST. Upon receiving the
HTTP DELETE request, the WHIP session will be removed and the
resources freed on the media server, terminating the ICE and DTLS
sessions.
A media server terminating a session MUST follow the procedures in
Section 5.2 of [RFC7675] for immediate revocation of consent.
The WHIP endpoints MUST return an "405 Method Not Allowed" response
for any HTTP request method different than OPTIONS and POST on the
endpoint URL in order to reserve their usage for future versions of
this protocol specification.
The WHIP endpoints MUST support OPTIONS requests for Cross-Origin
Resource Sharing (CORS) as defined in [FETCH]. The "200 OK" response
to any OPTIONS request SHOULD include an "Accept-Post" header with a
media type value of "application/sdp" as per [W3C.REC-ldp-20150226].
The WHIP sessions MUST return an "405 Method Not Allowed" response
for any HTTP request method different than PATCH and DELETE on the
session URLs in order to reserve their usage for future versions of
this protocol specification.
4.1. ICE support
ICE [RFC8845] is a protocol addressing the complexities of Network
Address Translation (NAT) traversal, commonly encountered in Internet
communication. NATs hinder direct communication between devices on
different local networks, posing challenges for real-time
applications. ICE facilitates seamless connectivity by employing
techniques to discover and negotiate efficient communication paths.
Trickle ICE [RFC8838] optimizes the connectivity process by
incrementally sharing potential communication paths, reducing
latency, and facilitating quicker establishment.
ICE Restarts are crucial for maintaining connectivity in dynamic
network conditions or disruptions, allowing devices to re-establish
communication paths without complete renegotiation. This ensures
minimal latency and reliable real-time communication.
Murillo & Gouaillard Expires 10 August 2024 [Page 8]
Internet-Draft whip February 2024
Trickle ICE and ICE restart support are RECOMMENDED for both WHIP
sessions and clients.
4.1.1. HTTP PATCH request usage
The WHIP client MAY perform trickle ICE or ICE restarts by sending an
HTTP PATCH request as per [RFC5789] to the WHIP session URL, with a
body containing a SDP fragment with media type "application/trickle-
ice-sdpfrag" as specified in [RFC8840] carrying the relevant ICE
information.
If the HTTP PATCH to the WHIP session has a content type different
than "application/trickle-ice-sdpfrag", the WHIP session MUST reject
the HTTP PATCH request with a "415 Unsupported Media Type" error
response. If the SDP fragment is malformed, the WHIP session MUST
reject the HTTP PATCH with a "400 Bad Request" error response.
If the WHIP session supports either Trickle ICE or ICE restarts, but
not both, it MUST return a "422 Unprocessable Content" response for
the HTTP PATCH requests that are not supported as per Section 15.5.21
of [RFC9110].
The WHIP client MAY send overlapping HTTP PATCH requests to one WHIP
session. Consequently, as those HTTP PATCH requests may be received
out-of-order by the WHIP session, if WHIP session supports ICE
restarts, it MUST generate a unique strong entity-tag identifying the
ICE session as per Section 8.8.3 of [RFC9110], being OPTIONAL
otherwise. The initial value of the entity-tag identifying the
initial ICE session MUST be returned in an ETag header field in the
"201 Created" response to the initial POST request to the WHIP
endpoint.
WHIP clients SHOULD NOT use entity-tag validation when matching a
specific ICE session is not required, such as for example when
initiating a DELETE request to terminate a session. WHIP sessions
MUST ignore any entity-tag value sent by the WHIP client when ICE
session matching is not required, as in the HTTP DELETE request.
4.1.2. Trickle ICE
Depending on the Trickle ICE support on the WHIP client, the initial
offer by the WHIP client MAY be sent after the full ICE gathering is
complete with the full list of ICE candidates, or it MAY only contain
local candidates (or even an empty list of candidates) as per
[RFC8845]. For the purpose of reducing setup times, when using
Trickle ICE the WHIP client SHOULD send the SDP offer as soon as
possible, containing either locally gathered ICE candidates or an
empty list of candidates.
Murillo & Gouaillard Expires 10 August 2024 [Page 9]
Internet-Draft whip February 2024
In order to simplify the protocol, the WHIP session cannot signal
additional ICE candidates to the WHIP client after the SDP answer has
been sent. The WHIP endpoint SHALL gather all the ICE candidates for
the media server before responding to the client request and the SDP
answer SHALL contain the full list of ICE candidates of the media
server.
As the WHIP client needs to know the WHIP session URL associated with
the ICE session in order to send a PATCH request containing new ICE
candidates, it MUST wait and buffer any gathered candidates until the
"201 Created" HTTP response to the initial POST request is received.
In order to lower the HTTP traffic and processing time required the
WHIP client SHOULD send a single aggregated HTTP PATCH request with
all the buffered ICE candidates once the response is received.
Additionally, if ICE restarts are supported by the WHIP session, the
WHIP client needs to know the entity-tag associated with the ICE
session in order to send a PATCH request containing new ICE
candidates, so it MUST also wait and buffer any gathered candidates
until it receives the HTTP response with the new entity-tag value to
the last PATCH request performing an ICE restart.
WHIP clients generating the HTTP PATCH body with the SDP fragment and
its subsequent processing by WHIP sessions MUST follow to the
guidelines defined in Section 4.4 of [RFC8840] with the following
considerations:
* As per [RFC8829], only m-sections not marked as bundle-only can
gather ICE candidates, so given that the "max-bundle" policy is
being used, the SDP fragment will contain only the offerer-tagged
m-line of the bundle group.
* The WHIP client MAY exclude ICE candidates from the HTTP PATCH
body if they have already been confirmed by the WHIP session with
a successful HTTP response to a previous HTTP PATCH request.
If the WHIP session is using entity-tags for identifying the ICE
sessions in explained in Section 4.1.1, a WHIP client sending a PATCH
request for performing trickle ICE MUST include an "If-Match" header
field with the latest known entity-tag as per Section 13.1.1 of
[RFC9110]. When the PATCH request is received by the WHIP session,
it MUST compare the indicated entity-tag value with the current
entity-tag of the resource as per Section 13.1.1 of [RFC9110] and
return a "412 Precondition Failed" response if they do not match. If
the HTTP PATCH request does not contain an "If-Match" header the WHIP
session MUST return an "428 Precondition Required" response as per
Section 3 of [RFC6585].
Murillo & Gouaillard Expires 10 August 2024 [Page 10]
Internet-Draft whip February 2024
When a WHIP session receives a PATCH request that adds new ICE
candidates without performing an ICE restart, it MUST return a "204
No Content" response without a body and MUST NOT include an ETag
header in the response. If the WHIP session does not support a
candidate transport or is not able to resolve the connection address,
it MUST silently discard the candidate and continue processing the
rest of the request normally.
PATCH /session/id HTTP/1.1
Host: whip.example.com
If-Match: "xyzzy"
Content-Type: application/trickle-ice-sdpfrag
Content-Length: 576
a=group:BUNDLE 0 1
m=audio 9 UDP/TLS/RTP/SAVPF 111
a=mid:0
a=ice-ufrag:EsAw
a=ice-pwd:P2uYro0UCOQ4zxjKXaWCBui1
a=candidate:1387637174 1 udp 2122260223 192.0.2.1 61764 typ host generation 0 ufrag EsAw network-id 1
a=candidate:3471623853 1 udp 2122194687 198.51.100.2 61765 typ host generation 0 ufrag EsAw network-id 2
a=candidate:473322822 1 tcp 1518280447 192.0.2.1 9 typ host tcptype active generation 0 ufrag EsAw network-id 1
a=candidate:2154773085 1 tcp 1518214911 198.51.100.2 9 typ host tcptype active generation 0 ufrag EsAw network-id 2
a=end-of-candidates
HTTP/1.1 204 No Content
Figure 3: Example of a Trickle ICE request and response
4.1.3. ICE Restarts
As defined in [RFC8839], when an ICE restart occurs, a new SDP offer/
answer exchange is triggered. However, as WHIP does not support
renegotiation of non-ICE related SDP information, a WHIP client will
not send a new offer when an ICE restart occurs. Instead, the WHIP
client and WHIP session will only exchange the relevant ICE
information via an HTTP PATCH request as defined in Section 4.1.1 and
MUST assume that the previously negotiated non-ICE related SDP
information still apply after the ICE restart.
Murillo & Gouaillard Expires 10 August 2024 [Page 11]
Internet-Draft whip February 2024
When performing an ICE restart, the WHIP client MUST include the
updated "ice-pwd" and "ice-ufrag" in the SDP fragment of the HTTP
PATCH request body as well as the new set of gathered ICE candidates
as defined in [RFC8840]. Similar what is defined in Section 4.1.2,
as per [RFC8829] only m-sections not marked as bundle-only can gather
ICE candidates, so given that the "max-bundle" policy is being used,
the SDP fragment will contain only the offerer-tagged m-line of the
bundle group. A WHIP client sending a PATCH request for performing
ICE restart MUST contain an "If-Match" header field with a field-
value "*" as per Section 13.1.1 of [RFC9110].
[RFC8840] states that an agent MUST discard any received requests
containing "ice-pwd" and "ice-ufrag" attributes that do not match
those of the current ICE Negotiation Session, however, any WHIP
session receiving an updated "ice-pwd" and "ice-ufrag" attributes
MUST consider the request as performing an ICE restart instead and,
if supported, SHALL return a "200 OK" with an "application/trickle-
ice-sdpfrag" body containing the new ICE username fragment and
password and a new set of ICE candidates for the WHIP session. Also,
the "200 OK" response for a successful ICE restart MUST contain the
new entity-tag corresponding to the new ICE session in an ETag
response header field and MAY contain a new set of ICE candidates for
the media server.
As defined in Section 4.4.1.1.1 of [RFC8839] the set of candidates
after an ICE restart may include some, none, or all of the previous
candidates for that data stream and may include a totally new set of
candidates. So after performing a successful ICE restart, both the
WHIP client and the WHIP session MUST replace the previous set of
remote candidates with the new set exchanged in the HTTP PATCH
request and response, discarding any remote ICE candidate not present
on the new set. Both the WHIP client and the WHIP session MUST
ensure that the HTTP PATCH requests and response bodies include the
same 'ice-options,' 'ice-pacing,' and 'ice-lite' attributes as those
used in the SDP offer or answer.
If the ICE restart request cannot be satisfied by the WHIP session,
the resource MUST return an appropriate HTTP error code and MUST NOT
terminate the session immediately and keep the existing ICE session.
The WHIP client MAY retry performing a new ICE restart or terminate
the session by issuing an HTTP DELETE request instead. In any case,
the session MUST be terminated if the ICE consent expires as a
consequence of the failed ICE restart as per Section 5.1 of
[RFC7675].
In case of unstable network conditions, the ICE restart HTTP PATCH
requests and responses might be received out of order. In order to
mitigate this scenario, when the client performs an ICE restart, it
Murillo & Gouaillard Expires 10 August 2024 [Page 12]
Internet-Draft whip February 2024
MUST discard any previous ICE username and passwords fragments and
ignore any further HTTP PATCH response received from a pending HTTP
PATCH request. WHIP clients MUST apply only the ICE information
received in the response to the last sent request. If there is a
mismatch between the ICE information at the WHIP client and at the
WHIP session (because of an out-of-order request), the STUN requests
will contain invalid ICE information and will be dropped by the
receiving side. If this situation is detected by the WHIP client, it
MUST send a new ICE restart request to the server.
PATCH /session/id HTTP/1.1
Host: whip.example.com
If-Match: "*"
Content-Type: application/trickle-ice-sdpfrag
Content-Length: 82
a=ice-options:trickle ice2
a=group:BUNDLE 0 1
m=audio 9 UDP/TLS/RTP/SAVPF 111
a=mid:0
a=ice-ufrag:ysXw
a=ice-pwd:vw5LmwG4y/e6dPP/zAP9Gp5k
a=candidate:1387637174 1 udp 2122260223 192.0.2.1 61764 typ host generation 0 ufrag EsAw network-id 1
a=candidate:3471623853 1 udp 2122194687 198.51.100.2 61765 typ host generation 0 ufrag EsAw network-id 2
a=candidate:473322822 1 tcp 1518280447 192.0.2.1 9 typ host tcptype active generation 0 ufrag EsAw network-id 1
a=candidate:2154773085 1 tcp 1518214911 198.51.100.2 9 typ host tcptype active generation 0 ufrag EsAw network-id 2
HTTP/1.1 200 OK
ETag: "abccd"
Content-Type: application/trickle-ice-sdpfrag
Content-Length: 252
a=ice-lite
a=ice-options:trickle ice2
a=group:BUNDLE 0 1
m=audio 9 UDP/TLS/RTP/SAVPF 111
a=mid:0
a=ice-ufrag:289b31b754eaa438
a=ice-pwd:0b66f472495ef0ccac7bda653ab6be49ea13114472a5d10a
a=candidate:1 1 udp 2130706431 198.51.100.1 39132 typ host
a=end-of-candidates
Figure 4: Example of an ICE restart request and response
Murillo & Gouaillard Expires 10 August 2024 [Page 13]
Internet-Draft whip February 2024
4.2. WebRTC constraints
In order to reduce the complexity of implementing WHIP in both
clients and media servers, WHIP imposes the following restrictions
regarding WebRTC usage:
4.2.1. SDP Bundle
Both the WHIP client and the WHIP endpoint SHALL support [RFC9143]
and use "max-bundle" policy as defined in [RFC8829]. The WHIP client
and the media server MUST support multiplexed media associated with
the BUNDLE group as per Section 9 of [RFC9143]. In addition, per
[RFC9143] the WHIP client and media server SHALL use RTP/RTCP
multiplexing for all bundled media. In order to reduce the network
resources required at the media server, both The WHIP client and WHIP
endpoints MUST include the "rtcp-mux-only" attribute in each bundled
"m=" sections as per Section 3 of [RFC8858].
4.2.2. Single MediaStream
WHIP only supports a single MediaStream as defined in [RFC8830] and
therefore all "m=" sections MUST contain an "msid" attribute with the
same value. The MediaStream MUST contain at least one
MediaStreamTrack of any media kind and it MUST NOT have two or more
than MediaStreamTracks for the same media (audio or video). However,
it would be possible for future revisions of this spec to allow more
than a single MediaStream or MediaStreamTrack of each media kind, so
in order to ensure forward compatibility, if the number of audio and
or video MediaStreamTracks or number of MediaStreams are not
supported by the WHIP endpoint, it MUST reject the HTTP POST request
with a "406 Not Acceptable" error response.
4.2.3. No partially successful answers
The WHIP endpoint SHOULD NOT reject individual "m=" sections as per
Section 5.3.1 of [RFC8829] in case there is any error processing the
"m=" section, but reject the HTTP POST request with a "406 Not
Acceptable" error response to prevent having partially successful
ingest sessions which can be misleading to end users.
4.2.4. DTLS setup role and SDP "setup" attribute
When a WHIP client sends an SDP offer, it SHOULD insert an SDP
"setup" attribute with an "actpass" attribute value, as defined in
[RFC8842]. However, if the WHIP client only implements the DTLS
client role, it MAY use an SDP "setup" attribute with an "active"
attribute value. If the WHIP endpoint does not support an SDP offer
with an SDP "setup" attribute with an "active" attribute value, it
Murillo & Gouaillard Expires 10 August 2024 [Page 14]
Internet-Draft whip February 2024
SHOULD reject the request with a "422 Unprocessable Entity" response.
NOTE: [RFC8842] defines that the offerer must insert an SDP "setup"
attribute with an "actpass" attribute value. However, the WHIP
client will always communicate with a media server that is expected
to support the DTLS server role, in which case the client might
choose to only implement support for the DTLS client role.
4.2.5. Trickle ICE and ICE restarts
The media server SHOULD support full ICE, unless it is connected to
the Internet with an IP address that is accessible by each WHIP
client that is authorized to use it, in which case it MAY support
only ICE lite. The WHIP client MUST implement and use full ICE.
Trickle ICE and ICE restarts support is OPTIONAL for both the WHIP
clients and media servers as explained in Section 4.1.
4.3. Load balancing and redirections
WHIP endpoints and media servers might not be colocated on the same
server, so it is possible to load balance incoming requests to
different media servers.
WHIP clients SHALL support HTTP redirections as per Section 15.4 of
[RFC9110]. In order to avoid POST requests to be redirected as GET
requests, status codes 301 and 302 MUST NOT be used and the preferred
method for performing load balancing is via the "307 Temporary
Redirect" response status code as described in Section 15.4.8 of
[RFC9110]. Redirections are not required to be supported for the
PATCH and DELETE requests.
In case of high load, the WHIP endpoints MAY return a "503 Service
Unavailable" response indicating that the server is currently unable
to handle the request due to a temporary overload or scheduled
maintenance as described in Section 15.6.4 of [RFC9110], which will
likely be alleviated after some delay. The WHIP endpoint might send
a Retry-After header field indicating the minimum time that the user
agent ought to wait before making a follow-up request as described in
Section 10.2.3 of [RFC9110].
4.4. STUN/TURN server configuration
The WHIP endpoint MAY return STUN/TURN server configuration URLs and
credentials usable by the client in the "201 Created" response to the
HTTP POST request to the WHIP endpoint URL.
Murillo & Gouaillard Expires 10 August 2024 [Page 15]
Internet-Draft whip February 2024
A reference to each STUN/TURN server will be returned using the
"Link" header field [RFC8288] with a "rel" attribute value of "ice-
server". The Link target URI is the server URI as defined in
[RFC7064] and [RFC7065]. The credentials are encoded in the Link
target attributes as follows:
* username: If the Link header field represents a TURN server, and
credential-type is "password", then this attribute specifies the
username to use with that TURN server.
* credential: If the "credential-type" attribute is missing or has a
"password" value, the credential attribute represents a long-term
authentication password, as described in Section 9.2 of [RFC8489].
* credential-type: If the Link header field represents a TURN
server, then this attribute specifies how the credential attribute
value should be used when that TURN server requests authorization.
The default value if the attribute is not present is "password".
Link: <stun:stun.example.net>; rel="ice-server"
Link: <turn:turn.example.net?transport=udp>; rel="ice-server";
username="user"; credential="myPassword"; credential-type="password"
Link: <turn:turn.example.net?transport=tcp>; rel="ice-server";
username="user"; credential="myPassword"; credential-type="password"
Link: <turns:turn.example.net?transport=tcp>; rel="ice-server";
username="user"; credential="myPassword"; credential-type="password"
Figure 5: Example of a STUN/TURN servers configuration
NOTE: The naming of both the "rel" attribute value of "ice-server"
and the target attributes follows the one used on the W3C WebRTC
recommendation [W3C.REC-webrtc-20210126] RTCConfiguration dictionary
in section 4.2.1. "rel" attribute value of "ice-server" is not
prepended with the "urn:ietf:params:whip:" so it can be reused by
other specifications which may use this mechanism to configure the
usage of STUN/TURN servers.
NOTE: Depending on the ICE Agent implementation, the WHIP client may
need to call the setConfiguration method before calling the
setLocalDescription method with the local SDP offer in order to avoid
having to perform an ICE restart for applying the updated STUN/TURN
server configuration on the next ICE gathering phase.
There are some WebRTC implementations that do not support updating
the STUN/TURN server configuration after the local offer has been
created as specified in Section 4.1.18 of [RFC8829]. In order to
support these clients, the WHIP endpoint MAY also include the STUN/
TURN server configuration on the responses to OPTIONS request sent to
Murillo & Gouaillard Expires 10 August 2024 [Page 16]
Internet-Draft whip February 2024
the WHIP endpoint URL before the POST request is sent. However, this
method is not NOT RECOMMENDED to be used by the WHIP clients and, if
supported by the underlying WHIP client's webrtc implementation, the
WHIP client SHOULD wait for the information to be returned by the
WHIP endpoint on the response of the HTTP POST request instead.
The generation of the TURN server credentials may require performing
a request to an external provider, which can both add latency to the
OPTIONS request processing and increase the processing required to
handle that request. In order to prevent this, the WHIP endpoint
SHOULD NOT return the STUN/TURN server configuration if the OPTIONS
request is a preflight request for CORS as defined in [FETCH], that
is, if The OPTIONS request does not contain an Access-Control-
Request-Method with "POST" value and the the Access-Control-Request-
Headers HTTP header does not contain the "Link" value.
The WHIP clients MAY also support configuring the STUN/TURN server
URIs with long term credentials provided by either the broadcasting
service or an external TURN provider, overriding the values provided
by the WHIP endpoint.
4.5. Authentication and authorization
All WHIP endpoints, sessions and clients MUST support HTTP
Authentication as per Section 11 of [RFC9110] and in order to ensure
interoperability, bearer token authentication as defined in the next
section MUST be supported by all WHIP entities. However this does
not preclude the support of additional HTTP authentication schemes as
defined in Section 11.6 of [RFC9110].
4.5.1. Bearer token authentication
WHIP endpoints and sessions MAY require the HTTP request to be
authenticated using an HTTP Authorization header field with a Bearer
token as specified in Section 2.1 of [RFC6750]. WHIP clients MUST
implement this authentication and authorization mechanism and send
the HTTP Authorization header field in all HTTP requests sent to
either the WHIP endpoint or session except the preflight OPTIONS
requests for CORS.
The nature, syntax, and semantics of the bearer token, as well as how
to distribute it to the client, is outside the scope of this
document. Some examples of the kind of tokens that could be used
are, but are not limited to, JWT tokens as per [RFC6750] and
[RFC8725] or a shared secret stored on a database. The tokens are
typically made available to the end user alongside the WHIP endpoint
URL and configured on the WHIP clients (similar to the way RTMP URLs
and Stream Keys are distributed).
Murillo & Gouaillard Expires 10 August 2024 [Page 17]
Internet-Draft whip February 2024
WHIP endpoints and sessions could perform the authentication and
authorization by encoding an authentication token within the URLs for
the WHIP endpoints or sessions instead. In case the WHIP client is
not configured to use a bearer token, the HTTP Authorization header
field must not be sent in any request.
4.6. Simulcast and scalable video coding
Simulcast as per [RFC8853] MAY be supported by both the media servers
and WHIP clients through negotiation in the SDP offer/answer.
If the client supports simulcast and wants to enable it for
ingesting, it MUST negotiate the support in the SDP offer according
to the procedures in Section 5.3 of [RFC8853]. A server accepting a
simulcast offer MUST create an answer according to the procedures in
Section 5.3.2 of [RFC8853].
It is possible for both media servers and WHIP clients to support
Scalable Video Coding (SVC). However, as there is no universal
negotiation mechanism in SDP for SVC, the encoder must consider the
negotiated codec(s), intended usage, and SVC support in available
decoders when configuring SVC.
4.7. Protocol extensions
In order to support future extensions to be defined for the WHIP
protocol, a common procedure for registering and announcing the new
extensions is defined.
Protocol extensions supported by the WHIP sessions MUST be advertised
to the WHIP client in the "201 Created" response to the initial HTTP
POST request sent to the WHIP endpoint. The WHIP endpoint MUST
return one "Link" header field for each extension that it supports,
with the extension "rel" attribute value containing the extension URN
and the URL for the HTTP resource that will be available for
receiving requests related to that extension.
Protocol extensions are optional for both WHIP clients and servers.
WHIP clients MUST ignore any Link attribute with an unknown "rel"
attribute value and WHIP session MUST NOT require the usage of any of
the extensions.
Each protocol extension MUST register a unique "rel" attribute value
at IANA starting with the prefix: "urn:ietf:params:whip:ext" as
defined in Section 6.3.
Murillo & Gouaillard Expires 10 August 2024 [Page 18]
Internet-Draft whip February 2024
For example, considering a potential extension of server-to-client
communication using server-sent events as specified in
https://html.spec.whatwg.org/multipage/server-sent-
events.html#server-sent-events, the URL for connecting to the server-
sent event resource for the ingested stream could be returned in the
initial HTTP "201 Created" response with a "Link" header field and a
"rel" attribute of "urn:ietf:params:whip:ext:example:server-sent-
events" (this document does not specify such an extension, and uses
it only as an example).
In this theoretical case, the "201 Created" response to the HTTP POST
request would look like:
HTTP/1.1 201 Created
Content-Type: application/sdp
Location: https://whip.example.com/session/id
Link: <https://whip.ietf.org/publications/213786HF/sse>;
rel="urn:ietf:params:whip:ext:example:server-sent-events"
Figure 6: Example of a WHIP protocol extension
5. Security Considerations
This document specifies a new protocol on top of HTTP and WebRTC,
thus, security protocols and considerations from related
specifications apply to the WHIP specification. These include:
* WebRTC security considerations: [RFC8826]. HTTPS SHALL be used in
order to preserve the WebRTC security model.
* Transport Layer Security (TLS): [RFC8446] and [RFC9147].
* HTTP security: Section 11 of [RFC9112] and Section 17 of
[RFC9110].
* URI security: Section 7 of [RFC3986].
On top of that, the WHIP protocol exposes a thin new attack surface
specific of the REST API methods used within it:
* HTTP POST flooding and resource exhaustion: It would be possible
for an attacker in possession of authentication credentials valid
for ingesting a WHIP stream to make multiple HTTP POST to the WHIP
endpoint. This will force the WHIP endpoint to process the
incoming SDP and allocate resources for being able to setup the
DTLS/ICE connection. While the malicious client does not need to
initiate the DTLS/ICE connection at all, the WHIP session will
have to wait for the DTLS/ICE connection timeout in order to
Murillo & Gouaillard Expires 10 August 2024 [Page 19]
Internet-Draft whip February 2024
release the associated resources. If the connection rate is high
enough, this could lead to resource exhaustion on the servers
handling the requests and it will not be able to process
legitimate incoming ingests. In order to prevent this scenario,
WHIP endpoints SHOULD implement a rate limit and avalanche control
mechanism for incoming initial HTTP POST requests.
* Insecure direct object references (IDOR) on the WHIP session
locations: If the URLs returned by the WHIP endpoint for the WHIP
sessions location are easy to guess, it would be possible for an
attacker to send multiple HTTP DELETE requests and terminate all
the WHIP sessions currently running. In order to prevent this
scenario, WHIP endpoints SHOULD generate URLs with enough
randomness, using a cryptographically secure pseudorandom number
generator following the best practices in Randomness Requirements
for Security [RFC4086], and implement a rate limit and avalanche
control mechanism for HTTP DELETE requests. The security
considerations for Universally Unique IDentifier (UUID) [RFC4122],
Section 6 are applicable for generating the WHIP sessions location
URL.
* HTTP PATCH flooding: Similar to the HTTP POST flooding, a
malicious client could also create a resource exhaustion by
sending multiple HTTP PATCH request to the WHIP session, although
the WHIP sessions can limit the impact by not allocating new ICE
candidates and reusing the existing ICE candidates when doing ICE
restarts. In order to prevent this scenario, WHIP endpoints
SHOULD implement a rate limit and avalanche control mechanism for
incoming HTTP PATCH requests.
6. IANA Considerations
This specification adds a new link relation type and a registry for
URN sub-namespaces for WHIP protocol extensions.
6.1. Link Relation Type: ice-server
The link relation type below has been registered by IANA per
Section 4.2 of [RFC8288].
Relation Name: ice-server
Description: Conveys the STUN and TURN servers that can be used by an
ICE Agent to establish a connection with a peer.
Reference: TBD
Murillo & Gouaillard Expires 10 August 2024 [Page 20]
Internet-Draft whip February 2024
6.2. Registration of WHIP URN Sub-namespace and WHIP Registry
IANA is asked to add an entry to the "IETF URN Sub-namespace for
Registered Protocol Parameter Identifiers" registry and create a sub-
namespace for the Registered Parameter Identifier as per [RFC3553]:
"urn:ietf:params:whip".
To manage this sub-namespace, IANA is asked to create the "WebRTC-
HTTP ingestion protocol (WHIP) URNs" registry, which is used to
manage entries within the "urn:ietf:params:whip" namespace. The
registry description is as follows:
* Registry name: WebRTC-HTTP ingestion protocol (WHIP) URNs
* Specification: this document (RFC TBD)
* Registration policy: Specification Required
* Repository: See Section Section 6.3
* Index value: See Section Section 6.3
6.3. URN Sub-namespace for WHIP
WHIP endpoint utilizes URNs to identify the supported WHIP protocol
extensions on the "rel" attribute of the Link header as defined in
Section 4.7.
This section creates and registers an IETF URN Sub-namespace for use
in the WHIP specifications and future extensions.
6.3.1. Specification Template
Namespace ID:
* The Namespace ID "whip" has been assigned.
Registration Information:
* Version: 1
* Date: TBD
Declared registrant of the namespace:
* Registering organization: The Internet Engineering Task Force.
Murillo & Gouaillard Expires 10 August 2024 [Page 21]
Internet-Draft whip February 2024
* Designated contact: A designated expert will monitor the WHIP
public mailing list, "wish@ietf.org".
Declaration of Syntactic Structure:
* The Namespace Specific String (NSS) of all URNs that use the
"whip" Namespace ID shall have the following structure:
urn:ietf:params:whip:{type}:{name}:{other}.
* The keywords have the following meaning:
- type: The entity type. This specification only defines the
"ext" type.
- name: A required US-ASCII string that conforms to the URN
syntax requirements (see [RFC8141]) and defines a major
namespace of a WHIP protocol extension. The value MAY also be
an industry name or organization name.
- other: Any US-ASCII string that conforms to the URN syntax
requirements (see [RFC8141]) and defines the sub-namespace
(which MAY be further broken down in namespaces delimited by
colons) as needed to uniquely identify an WHIP protocol
extension.
Relevant Ancillary Documentation:
* None
Identifier Uniqueness Considerations:
* The designated contact shall be responsible for reviewing and
enforcing uniqueness.
Identifier Persistence Considerations:
* Once a name has been allocated, it MUST NOT be reallocated for a
different purpose.
* The rules provided for assignments of values within a sub-
namespace MUST be constructed so that the meanings of values
cannot change.
* This registration mechanism is not appropriate for naming values
whose meanings may change over time.
Process of Identifier Assignment:
Murillo & Gouaillard Expires 10 August 2024 [Page 22]
Internet-Draft whip February 2024
* Namespace with type "ext" (e.g., "urn:ietf:params:whip:ext") is
reserved for IETF-approved WHIP specifications.
Process of Identifier Resolution:
* None specified.
Rules for Lexical Equivalence:
* No special considerations; the rules for lexical equivalence
specified in [RFC8141] apply.
Conformance with URN Syntax:
* No special considerations.
Validation Mechanism:
* None specified.
Scope:
* Global.
6.4. Registering WHIP Protocol Extensions URNs
This section defines the process for registering new WHIP protocol
extensions URNs with IANA in the "WebRTC-HTTP ingestion protocol
(WHIP) URNs" registry (see Section 6.3).
A WHIP Protocol Extension URNs is used as a value in the "rel"
attribute of the Link header as defined in Section 4.7 for the
purpose of signaling the WHIP protocol extensions supported by the
WHIP endpoints.
WHIP Protocol Extensions URNs have a "ext" type as defined in
Section 6.3.
6.4.1. Registration Procedure
The IETF has created a mailing list, "wish@ietf.org", which can be
used for public discussion of WHIP protocol extensions proposals
prior to registration. Use of the mailing list is strongly
encouraged. The IESG has appointed a designated expert RFC8126 who
will monitor the wish@ietf.org mailing list and review registrations.
Murillo & Gouaillard Expires 10 August 2024 [Page 23]
Internet-Draft whip February 2024
Registration of new "ext" type URNs (in the namespace
"urn:ietf:params:whip:ext") belonging to a WHIP Protocol Extension
MUST be documented in a permanent and readily available public
specification, in sufficient detail so that interoperability between
independent implementations is possible and reviewed by the
designated expert as per Section 4.6 of [BCP26] . An RFC is REQUIRED
for the registration of new value data types that modify existing
properties. An RFC is also REQUIRED for registration of WHIP
Protocol Extensions URNs that modify WHIP Protocol Extensions
previously documented in an existing RFC.
The registration procedure begins when a completed registration
template, defined in the sections below, is sent to iana@iana.org.
Decisions made by the designated expert can be appealed to an
Applications and Real Time (ART) Area Director, then to the IESG.
The normal appeals procedure described in [BCP9] is to be followed.
Once the registration procedure concludes successfully, IANA creates
or modifies the corresponding record in the WHIP Protocol Extension
registry.
An RFC specifying one or more new WHIP Protocol Extension URNs MUST
include the completed registration templates, which MAY be expanded
with additional information. These completed templates are intended
to go in the body of the document, not in the IANA Considerations
section. The RFC MUST include the syntax and semantics of any
extension-specific attributes that may be provided in a Link header
field advertising the extension.
6.4.2. Guidance for Designated Experts
The Designated Expert (DE) is expected to ascertain the existence of
suitable documentation (a specification) as described in RFC8126 and
to verify that the document is permanently and publicly available.
The DE is also expected to check the clarity of purpose and use of
the requested registration.
Additionally, the DE must verify that any request for one of these
registrations has been made available for review and comment within
the IETF: the DE will post the request to the WebRTC Ingest Signaling
over HTTPS (wish) Working Group mailing list (or a successor mailing
list designated by the IESG).
If the request comes from within the IETF, it should be documented in
an Internet-Draft. Lastly, the DE must ensure that any other request
for a code point does not conflict with work that is active or
already published within the IETF.
Murillo & Gouaillard Expires 10 August 2024 [Page 24]
Internet-Draft whip February 2024
6.4.3. WHIP Protocol Extension Registration Template
A WHIP Protocol Extension URNs is defined by completing the following
template:
* URN: A unique URN for the WHIP Protocol Extension (e.g.,
"urn:ietf:params:whip:ext:example:server-sent-events").
* Reference: A formal reference to the publicly available
specification
* Name: A descriptive name of the WHIP Protocol Extension extension
(e.g., "Sender Side events").
* Description: A brief description of the function of the extension,
in a short paragraph or two
* Contact information: Contact information for the organization or
person making the registration
7. Acknowledgements
The authors wish to thank Lorenzo Miniero, Juliusz Chroboczek, Adam
Roach, Nils Ohlmeier, Christer Holmberg, Cameron Elliott, Gustavo
Garcia, Jonas Birme, Sandro Gauci, Christer Holmberg and everyone
else in the WebRTC community that have provided comments, feedback,
text and improvement proposals on the document and contributed early
implementations of the spec.
8. References
8.1. Normative References
[BCP26] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, June 2017.
<https://www.rfc-editor.org/info/bcp26>
[BCP9] Bradner, S., "The Internet Standards Process -- Revision
3", BCP 9, RFC 2026, October 1996.
Dusseault, L. and R. Sparks, "Guidance on Interoperation
and Implementation Reports for Advancement to Draft
Standard", BCP 9, RFC 5657, September 2009.
Murillo & Gouaillard Expires 10 August 2024 [Page 25]
Internet-Draft whip February 2024
Housley, R., Crocker, D., and E. Burger, "Reducing the
Standards Track to Two Maturity Levels", BCP 9, RFC 6410,
October 2011.
Resnick, P., "Retirement of the "Internet Official
Protocol Standards" Summary Document", BCP 9, RFC 7100,
December 2013.
Kolkman, O., Bradner, S., and S. Turner, "Characterization
of Proposed Standards", BCP 9, RFC 7127, January 2014.
Dawkins, S., "Increasing the Number of Area Directors in
an IETF Area", BCP 9, RFC 7475, March 2015.
Halpern, J., Ed. and E. Rescorla, Ed., "IETF Stream
Documents Require IETF Rough Consensus", BCP 9, RFC 8789,
June 2020.
Rosen, B., "Responsibility Change for the RFC Series",
BCP 9, RFC 9282, June 2022.
<https://www.rfc-editor.org/info/bcp9>
[FETCH] WHATWG, "Fetch - Living Standard", n.d.,
<https://fetch.spec.whatwg.org>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model
with Session Description Protocol (SDP)", RFC 3264,
DOI 10.17487/RFC3264, June 2002,
<https://www.rfc-editor.org/rfc/rfc3264>.
[RFC3553] Mealling, M., Masinter, L., Hardie, T., and G. Klyne, "An
IETF URN Sub-namespace for Registered Protocol
Parameters", BCP 73, RFC 3553, DOI 10.17487/RFC3553, June
2003, <https://www.rfc-editor.org/rfc/rfc3553>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/rfc/rfc3986>.
Murillo & Gouaillard Expires 10 August 2024 [Page 26]
Internet-Draft whip February 2024
[RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker,
"Randomness Requirements for Security", BCP 106, RFC 4086,
DOI 10.17487/RFC4086, June 2005,
<https://www.rfc-editor.org/rfc/rfc4086>.
[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Unique IDentifier (UUID) URN Namespace", RFC 4122,
DOI 10.17487/RFC4122, July 2005,
<https://www.rfc-editor.org/rfc/rfc4122>.
[RFC5789] Dusseault, L. and J. Snell, "PATCH Method for HTTP",
RFC 5789, DOI 10.17487/RFC5789, March 2010,
<https://www.rfc-editor.org/rfc/rfc5789>.
[RFC6585] Nottingham, M. and R. Fielding, "Additional HTTP Status
Codes", RFC 6585, DOI 10.17487/RFC6585, April 2012,
<https://www.rfc-editor.org/rfc/rfc6585>.
[RFC6750] Jones, M. and D. Hardt, "The OAuth 2.0 Authorization
Framework: Bearer Token Usage", RFC 6750,
DOI 10.17487/RFC6750, October 2012,
<https://www.rfc-editor.org/rfc/rfc6750>.
[RFC7064] Nandakumar, S., Salgueiro, G., Jones, P., and M. Petit-
Huguenin, "URI Scheme for the Session Traversal Utilities
for NAT (STUN) Protocol", RFC 7064, DOI 10.17487/RFC7064,
November 2013, <https://www.rfc-editor.org/rfc/rfc7064>.
[RFC7065] Petit-Huguenin, M., Nandakumar, S., Salgueiro, G., and P.
Jones, "Traversal Using Relays around NAT (TURN) Uniform
Resource Identifiers", RFC 7065, DOI 10.17487/RFC7065,
November 2013, <https://www.rfc-editor.org/rfc/rfc7065>.
[RFC7675] Perumal, M., Wing, D., Ravindranath, R., Reddy, T., and M.
Thomson, "Session Traversal Utilities for NAT (STUN) Usage
for Consent Freshness", RFC 7675, DOI 10.17487/RFC7675,
October 2015, <https://www.rfc-editor.org/rfc/rfc7675>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8288] Nottingham, M., "Web Linking", RFC 8288,
DOI 10.17487/RFC8288, October 2017,
<https://www.rfc-editor.org/rfc/rfc8288>.
Murillo & Gouaillard Expires 10 August 2024 [Page 27]
Internet-Draft whip February 2024
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/rfc/rfc8446>.
[RFC8489] Petit-Huguenin, M., Salgueiro, G., Rosenberg, J., Wing,
D., Mahy, R., and P. Matthews, "Session Traversal
Utilities for NAT (STUN)", RFC 8489, DOI 10.17487/RFC8489,
February 2020, <https://www.rfc-editor.org/rfc/rfc8489>.
[RFC8725] Sheffer, Y., Hardt, D., and M. Jones, "JSON Web Token Best
Current Practices", BCP 225, RFC 8725,
DOI 10.17487/RFC8725, February 2020,
<https://www.rfc-editor.org/rfc/rfc8725>.
[RFC8826] Rescorla, E., "Security Considerations for WebRTC",
RFC 8826, DOI 10.17487/RFC8826, January 2021,
<https://www.rfc-editor.org/rfc/rfc8826>.
[RFC8829] Uberti, J., Jennings, C., and E. Rescorla, Ed.,
"JavaScript Session Establishment Protocol (JSEP)",
RFC 8829, DOI 10.17487/RFC8829, January 2021,
<https://www.rfc-editor.org/rfc/rfc8829>.
[RFC8830] Alvestrand, H., "WebRTC MediaStream Identification in the
Session Description Protocol", RFC 8830,
DOI 10.17487/RFC8830, January 2021,
<https://www.rfc-editor.org/rfc/rfc8830>.
[RFC8838] Ivov, E., Uberti, J., and P. Saint-Andre, "Trickle ICE:
Incremental Provisioning of Candidates for the Interactive
Connectivity Establishment (ICE) Protocol", RFC 8838,
DOI 10.17487/RFC8838, January 2021,
<https://www.rfc-editor.org/rfc/rfc8838>.
[RFC8839] Petit-Huguenin, M., Nandakumar, S., Holmberg, C., Keränen,
A., and R. Shpount, "Session Description Protocol (SDP)
Offer/Answer Procedures for Interactive Connectivity
Establishment (ICE)", RFC 8839, DOI 10.17487/RFC8839,
January 2021, <https://www.rfc-editor.org/rfc/rfc8839>.
[RFC8840] Ivov, E., Stach, T., Marocco, E., and C. Holmberg, "A
Session Initiation Protocol (SIP) Usage for Incremental
Provisioning of Candidates for the Interactive
Connectivity Establishment (Trickle ICE)", RFC 8840,
DOI 10.17487/RFC8840, January 2021,
<https://www.rfc-editor.org/rfc/rfc8840>.
Murillo & Gouaillard Expires 10 August 2024 [Page 28]
Internet-Draft whip February 2024
[RFC8842] Holmberg, C. and R. Shpount, "Session Description Protocol
(SDP) Offer/Answer Considerations for Datagram Transport
Layer Security (DTLS) and Transport Layer Security (TLS)",
RFC 8842, DOI 10.17487/RFC8842, January 2021,
<https://www.rfc-editor.org/rfc/rfc8842>.
[RFC8845] Duckworth, M., Ed., Pepperell, A., and S. Wenger,
"Framework for Telepresence Multi-Streams", RFC 8845,
DOI 10.17487/RFC8845, January 2021,
<https://www.rfc-editor.org/rfc/rfc8845>.
[RFC8853] Burman, B., Westerlund, M., Nandakumar, S., and M. Zanaty,
"Using Simulcast in Session Description Protocol (SDP) and
RTP Sessions", RFC 8853, DOI 10.17487/RFC8853, January
2021, <https://www.rfc-editor.org/rfc/rfc8853>.
[RFC8858] Holmberg, C., "Indicating Exclusive Support of RTP and RTP
Control Protocol (RTCP) Multiplexing Using the Session
Description Protocol (SDP)", RFC 8858,
DOI 10.17487/RFC8858, January 2021,
<https://www.rfc-editor.org/rfc/rfc8858>.
[RFC9110] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "HTTP Semantics", STD 97, RFC 9110,
DOI 10.17487/RFC9110, June 2022,
<https://www.rfc-editor.org/rfc/rfc9110>.
[RFC9112] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "HTTP/1.1", STD 99, RFC 9112, DOI 10.17487/RFC9112,
June 2022, <https://www.rfc-editor.org/rfc/rfc9112>.
[RFC9143] Holmberg, C., Alvestrand, H., and C. Jennings,
"Negotiating Media Multiplexing Using the Session
Description Protocol (SDP)", RFC 9143,
DOI 10.17487/RFC9143, February 2022,
<https://www.rfc-editor.org/rfc/rfc9143>.
[RFC9147] Rescorla, E., Tschofenig, H., and N. Modadugu, "The
Datagram Transport Layer Security (DTLS) Protocol Version
1.3", RFC 9147, DOI 10.17487/RFC9147, April 2022,
<https://www.rfc-editor.org/rfc/rfc9147>.
[W3C.REC-ldp-20150226]
Malhotra, A., Ed., Arwe, J., Ed., and S. Speicher, Ed.,
"Linked Data Platform 1.0", W3C REC REC-ldp-20150226, W3C
REC-ldp-20150226, 26 February 2015,
<https://www.w3.org/TR/2015/REC-ldp-20150226/>.
Murillo & Gouaillard Expires 10 August 2024 [Page 29]
Internet-Draft whip February 2024
8.2. Informative References
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261,
DOI 10.17487/RFC3261, June 2002,
<https://www.rfc-editor.org/rfc/rfc3261>.
[RFC6120] Saint-Andre, P., "Extensible Messaging and Presence
Protocol (XMPP): Core", RFC 6120, DOI 10.17487/RFC6120,
March 2011, <https://www.rfc-editor.org/rfc/rfc6120>.
[RFC7826] Schulzrinne, H., Rao, A., Lanphier, R., Westerlund, M.,
and M. Stiemerling, Ed., "Real-Time Streaming Protocol
Version 2.0", RFC 7826, DOI 10.17487/RFC7826, December
2016, <https://www.rfc-editor.org/rfc/rfc7826>.
[RFC8141] Saint-Andre, P. and J. Klensin, "Uniform Resource Names
(URNs)", RFC 8141, DOI 10.17487/RFC8141, April 2017,
<https://www.rfc-editor.org/rfc/rfc8141>.
[W3C.REC-webrtc-20210126]
Jennings, C., Ed., Boström, H., Ed., and J. Bruaroey, Ed.,
"WebRTC 1.0: Real-Time Communication Between Browsers",
W3C REC REC-webrtc-20210126, W3C REC-webrtc-20210126, 26
January 2021,
<https://www.w3.org/TR/2021/REC-webrtc-20210126/>.
Authors' Addresses
Sergio Garcia Murillo
Millicast
Email: sergio.garcia.murillo@cosmosoftware.io
Alexandre Gouaillard
CoSMo Software
Email: alex.gouaillard@cosmosoftware.io
Murillo & Gouaillard Expires 10 August 2024 [Page 30]
