draft-ietf-rtcweb-transports-07.txt | draft-ietf-rtcweb-transports-08.txt | |||
---|---|---|---|---|
Network Working Group H. Alvestrand | Network Working Group H. Alvestrand | |||
Internet-Draft Google | Internet-Draft Google | |||
Intended status: Standards Track October 22, 2014 | Intended status: Standards Track February 27, 2015 | |||
Expires: April 25, 2015 | Expires: August 31, 2015 | |||
Transports for WebRTC | Transports for WebRTC | |||
draft-ietf-rtcweb-transports-07 | draft-ietf-rtcweb-transports-08 | |||
Abstract | Abstract | |||
This document describes the data transport protocols used by WebRTC, | This document describes the data transport protocols used by WebRTC, | |||
including the protocols used for interaction with intermediate boxes | including the protocols used for interaction with intermediate boxes | |||
such as firewalls, relays and NAT boxes. | such as firewalls, relays and NAT boxes. | |||
Status of This Memo | Status of This Memo | |||
This Internet-Draft is submitted in full conformance with the | This Internet-Draft is submitted in full conformance with the | |||
skipping to change at page 1, line 32 | skipping to change at page 1, line 32 | |||
Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
Drafts is at http://datatracker.ietf.org/drafts/current/. | Drafts is at http://datatracker.ietf.org/drafts/current/. | |||
Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
This Internet-Draft will expire on April 25, 2015. | This Internet-Draft will expire on August 31, 2015. | |||
Copyright Notice | Copyright Notice | |||
Copyright (c) 2014 IETF Trust and the persons identified as the | Copyright (c) 2015 IETF Trust and the persons identified as the | |||
document authors. All rights reserved. | document authors. All rights reserved. | |||
This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
(http://trustee.ietf.org/license-info) in effect on the date of | (http://trustee.ietf.org/license-info) in effect on the date of | |||
publication of this document. Please review these documents | publication of this document. Please review these documents | |||
carefully, as they describe your rights and restrictions with respect | carefully, as they describe your rights and restrictions with respect | |||
to this document. Code Components extracted from this document must | to this document. Code Components extracted from this document must | |||
include Simplified BSD License text as described in Section 4.e of | include Simplified BSD License text as described in Section 4.e of | |||
the Trust Legal Provisions and are provided without warranty as | the Trust Legal Provisions and are provided without warranty as | |||
skipping to change at page 2, line 14 | skipping to change at page 2, line 14 | |||
Table of Contents | Table of Contents | |||
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 | |||
2. Requirements language . . . . . . . . . . . . . . . . . . . . 3 | 2. Requirements language . . . . . . . . . . . . . . . . . . . . 3 | |||
3. Transport and Middlebox specification . . . . . . . . . . . . 3 | 3. Transport and Middlebox specification . . . . . . . . . . . . 3 | |||
3.1. System-provided interfaces . . . . . . . . . . . . . . . 3 | 3.1. System-provided interfaces . . . . . . . . . . . . . . . 3 | |||
3.2. Ability to use IPv4 and IPv6 . . . . . . . . . . . . . . 3 | 3.2. Ability to use IPv4 and IPv6 . . . . . . . . . . . . . . 3 | |||
3.3. Usage of temporary IPv6 addresses . . . . . . . . . . . . 4 | 3.3. Usage of temporary IPv6 addresses . . . . . . . . . . . . 4 | |||
3.4. Middle box related functions . . . . . . . . . . . . . . 4 | 3.4. Middle box related functions . . . . . . . . . . . . . . 4 | |||
3.5. Transport protocols implemented . . . . . . . . . . . . . 6 | 3.5. Transport protocols implemented . . . . . . . . . . . . . 5 | |||
4. Media Prioritization . . . . . . . . . . . . . . . . . . . . 6 | 4. Media Prioritization . . . . . . . . . . . . . . . . . . . . 6 | |||
4.1. Usage of Quality of Service - DSCP and Multiplexing . . . 6 | 4.1. Usage of Quality of Service - DSCP and Multiplexing . . . 6 | |||
4.2. Local prioritization . . . . . . . . . . . . . . . . . . 8 | 4.2. Local prioritization . . . . . . . . . . . . . . . . . . 8 | |||
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 | 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 | |||
6. Security Considerations . . . . . . . . . . . . . . . . . . . 9 | 6. Security Considerations . . . . . . . . . . . . . . . . . . . 9 | |||
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 | 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 | |||
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 | 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 | |||
8.1. Normative References . . . . . . . . . . . . . . . . . . 9 | 8.1. Normative References . . . . . . . . . . . . . . . . . . 9 | |||
8.2. Informative References . . . . . . . . . . . . . . . . . 12 | 8.2. Informative References . . . . . . . . . . . . . . . . . 11 | |||
Appendix A. Change log . . . . . . . . . . . . . . . . . . . . . 12 | Appendix A. Change log . . . . . . . . . . . . . . . . . . . . . 12 | |||
A.1. Changes from -00 to -01 . . . . . . . . . . . . . . . . . 12 | A.1. Changes from -00 to -01 . . . . . . . . . . . . . . . . . 12 | |||
A.2. Changes from -01 to -02 . . . . . . . . . . . . . . . . . 13 | A.2. Changes from -01 to -02 . . . . . . . . . . . . . . . . . 12 | |||
A.3. Changes from -02 to -03 . . . . . . . . . . . . . . . . . 13 | A.3. Changes from -02 to -03 . . . . . . . . . . . . . . . . . 13 | |||
A.4. Changes from -03 to -04 . . . . . . . . . . . . . . . . . 14 | A.4. Changes from -03 to -04 . . . . . . . . . . . . . . . . . 13 | |||
A.5. Changes from -04 to -05 . . . . . . . . . . . . . . . . . 14 | A.5. Changes from -04 to -05 . . . . . . . . . . . . . . . . . 13 | |||
A.6. Changes from -05 to -06 . . . . . . . . . . . . . . . . . 14 | A.6. Changes from -05 to -06 . . . . . . . . . . . . . . . . . 14 | |||
A.7. Changes from -06 to -07 . . . . . . . . . . . . . . . . . 14 | A.7. Changes from -06 to -07 . . . . . . . . . . . . . . . . . 14 | |||
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 15 | A.8. Changes from -07 to -08 . . . . . . . . . . . . . . . . . 14 | |||
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 14 | ||||
1. Introduction | 1. Introduction | |||
WebRTC is a protocol suite aimed at real time multimedia exchange | WebRTC is a protocol suite aimed at real time multimedia exchange | |||
between browsers, and between browsers and other entities. | between browsers, and between browsers and other entities. | |||
WebRTC is described in the WebRTC overview document, | WebRTC is described in the WebRTC overview document, | |||
[I-D.ietf-rtcweb-overview], which also defines terminology used in | [I-D.ietf-rtcweb-overview], which also defines terminology used in | |||
this document. | this document. | |||
This document focuses on the data transport protocols that are used | This document focuses on the data transport protocols that are used | |||
by conforming implementations, including the protocols used for | by conforming implementations, including the protocols used for | |||
interaction with intermediate boxes such as firewalls, relays and NAT | interaction with intermediate boxes such as firewalls, relays and NAT | |||
boxes. | boxes. | |||
This protocol suite intends to satisfy the security considerations | This protocol suite intends to satisfy the security considerations | |||
described in the WebRTC security documents, | described in the WebRTC security documents, | |||
[I-D.ietf-rtcweb-security] and [I-D.ietf-rtcweb-security-arch]. | [I-D.ietf-rtcweb-security] and [I-D.ietf-rtcweb-security-arch]. | |||
This document describes requirements that apply to all WebRTC | This document describes requirements that apply to all WebRTC | |||
devices. When there are requirements that apply only to WebRTC User | devices. When there are requirements that apply only to WebRTC | |||
Agents (also called browsers) , this is called out. | browsers, this is called out by using the word "browser". | |||
The form "WebRTC endpoint" is used as a synonym for "WebRTC device" | ||||
in contexts where other text talks about endpoints. | ||||
2. Requirements language | 2. Requirements language | |||
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | |||
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this | "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this | |||
document are to be interpreted as described in RFC 2119 [RFC2119]. | document are to be interpreted as described in RFC 2119 [RFC2119]. | |||
3. Transport and Middlebox specification | 3. Transport and Middlebox specification | |||
3.1. System-provided interfaces | 3.1. System-provided interfaces | |||
The protocol specifications used here assume that the following | The protocol specifications used here assume that the following | |||
protocols are available to the WebRTC devices: | protocols are available to the implementations of the WebRTC | |||
protocols: | ||||
o UDP. This is the protocol assumed by most protocol elements | o UDP. This is the protocol assumed by most protocol elements | |||
described. | described. | |||
o TCP. This is used for HTTP/WebSockets, as well as for TURN/SSL | o TCP. This is used for HTTP/WebSockets, as well as for TURN/SSL | |||
and ICE-TCP. | and ICE-TCP. | |||
For both protocols, IPv4 and IPv6 support is assumed. | For both protocols, IPv4 and IPv6 support is assumed. | |||
For UDP, this specification assumes the ability to set the DSCP code | For UDP, this specification assumes the ability to set the DSCP code | |||
skipping to change at page 4, line 7 | skipping to change at page 4, line 5 | |||
access to ICMP or raw IP. | access to ICMP or raw IP. | |||
3.2. Ability to use IPv4 and IPv6 | 3.2. Ability to use IPv4 and IPv6 | |||
Web applications running in a WebRTC browser MUST be able to utilize | Web applications running in a WebRTC browser MUST be able to utilize | |||
both IPv4 and IPv6 where available - that is, when two peers have | both IPv4 and IPv6 where available - that is, when two peers have | |||
only IPv4 connectivity to each other, or they have only IPv6 | only IPv4 connectivity to each other, or they have only IPv6 | |||
connectivity to each other, applications running in the WebRTC | connectivity to each other, applications running in the WebRTC | |||
browser MUST be able to communicate. | browser MUST be able to communicate. | |||
WebRTC devices, when attached to networks with appropriate protocol | ||||
support MUST also be able to communicate using IPv6 and IPv4. | ||||
When TURN is used, and the TURN server has IPv4 or IPv6 connectivity | When TURN is used, and the TURN server has IPv4 or IPv6 connectivity | |||
to the peer or its TURN server, candidates of the appropriate types | to the peer or its TURN server, candidates of the appropriate types | |||
MUST be supported. The "Happy Eyeballs" specification for ICE | MUST be supported. The "Happy Eyeballs" specification for ICE | |||
[I-D.reddy-mmusic-ice-happy-eyeballs] SHOULD be supported. | [I-D.martinsen-mmusic-ice-dualstack-fairness] SHOULD be supported. | |||
3.3. Usage of temporary IPv6 addresses | 3.3. Usage of temporary IPv6 addresses | |||
The IPv6 default address selection specification [RFC6724] specifies | The IPv6 default address selection specification [RFC6724] specifies | |||
that temporary addresses [RFC4941] are to be preferred over permanent | that temporary addresses [RFC4941] are to be preferred over permanent | |||
addresses. This is a change from the rules specified by [RFC3484]. | addresses. This is a change from the rules specified by [RFC3484]. | |||
For applications that select a single address, this is usually done | For applications that select a single address, this is usually done | |||
by the IPV6_PREFER_SRC_TMP preference flag specified in [RFC5014]. | by the IPV6_PREFER_SRC_TMP preference flag specified in [RFC5014]. | |||
However, this rule is not completely obvious in the ICE scope. This | However, this rule is not completely obvious in the ICE scope. This | |||
is therefore clarified as follows: | is therefore clarified as follows: | |||
When a WebRTC endpoint gathers all IPv6 addresses on a host, and both | When a client gathers all IPv6 addresses on a host, and both | |||
temporary addresses and permanent addresses of the same scope are | temporary addresses and permanent addresses of the same scope are | |||
present, the client SHOULD discard the permanent addresses before | present, the client SHOULD discard the permanent addresses before | |||
forming pairs. This is consistent with the default policy described | forming pairs. This is consistent with the default policy described | |||
in [RFC6724]. | in [RFC6724]. | |||
3.4. Middle box related functions | 3.4. Middle box related functions | |||
Except when called out, all requirements in this section apply to all | ||||
WebRTC devices. | ||||
The primary mechanism to deal with middle boxes is ICE, which is an | The primary mechanism to deal with middle boxes is ICE, which is an | |||
appropriate way to deal with NAT boxes and firewalls that accept | appropriate way to deal with NAT boxes and firewalls that accept | |||
traffic from the inside, but only from the outside if it is in | traffic from the inside, but only from the outside if it is in | |||
response to inside traffic (simple stateful firewalls). | response to inside traffic (simple stateful firewalls). | |||
WebRTC endpoints MUST support ICE [RFC5245]. The implementation MUST | ICE [RFC5245] MUST be supported. The implementation MUST be a full | |||
be a full ICE implementation, not ICE-Lite. A full ICE | ICE implementation, not ICE-Lite. A full ICE implementation allows | |||
implementation allows interworking with both ICE and ICE-Lite | interworking with both ICE and ICE-Lite implementations when they are | |||
implementations when they are deployed appropriately. | deployed appropriately. | |||
In order to deal with situations where both parties are behind NATs | In order to deal with situations where both parties are behind NATs | |||
of the type that perform endpoint-dependent mapping (as defined in | of the type that perform endpoint-dependent mapping (as defined in | |||
[RFC5128] section 2.4), WebRTC endpoints MUST support TURN [RFC5766]. | [RFC5128] section 2.4), TURN [RFC5766] MUST be supported. | |||
WebRTC browsers MUST support configuration of STUN and TURN servers, | WebRTC browsers MUST support configuration of STUN and TURN servers, | |||
both from browser configuration and from an application. | both from browser configuration and from an application. | |||
In order to deal with firewalls that block all UDP traffic, the mode | In order to deal with firewalls that block all UDP traffic, the mode | |||
of TURN that uses TCP between the client and the server MUST be | of TURN that uses TCP between the client and the server MUST be | |||
supported, and the mode of TURN that uses TLS over TCP between the | supported, and the mode of TURN that uses TLS over TCP between the | |||
client and the server MUST be supported. See [RFC5766] section 2.1 | client and the server MUST be supported. See [RFC5766] section 2.1 | |||
for details. | for details. | |||
skipping to change at page 5, line 37 | skipping to change at page 5, line 31 | |||
their respective relay servers. | their respective relay servers. | |||
Third, using TCP only between the endpoint and its relay may result | Third, using TCP only between the endpoint and its relay may result | |||
in less issues with TCP in regards to real-time constraints, e.g. due | in less issues with TCP in regards to real-time constraints, e.g. due | |||
to head of line blocking. | to head of line blocking. | |||
ICE-TCP candidates [RFC6544] MUST be supported; this may allow | ICE-TCP candidates [RFC6544] MUST be supported; this may allow | |||
applications to communicate to peers with public IP addresses across | applications to communicate to peers with public IP addresses across | |||
UDP-blocking firewalls without using a TURN server. | UDP-blocking firewalls without using a TURN server. | |||
If ICE-TCP connections are used, RTP framing according to [RFC4571] | If TCP connections are used, RTP framing according to [RFC4571] MUST | |||
MUST be used for all content that doesn't have its own framing | be used, both for the RTP packets and for the DTLS packets used to | |||
mechanism. | carry data channels. | |||
The ALTERNATE-SERVER mechanism specified in [RFC5389] (STUN) section | The ALTERNATE-SERVER mechanism specified in [RFC5389] (STUN) section | |||
11 (300 Try Alternate) MUST be supported. | 11 (300 Try Alternate) MUST be supported. | |||
In order to deal with the scenario in which the media must traverse a | The WebRTC implementation MAY support accessing the Internet through | |||
HTTP Proxy, WebRTC browser MUST support the HTTP CONNECT request | an HTTP proxy. If it does so, it MUST support the "connect" header | |||
(Section 4.3.6 of [RFC7231]). WebRTC devices SHOULD support this | as specified in [I-D.ietf-httpbis-tunnel-protocol]. | |||
request. | ||||
The HTTP Proxy may require authentication and therefore, if HTTP | ||||
CONNECT request is supported, proxy authentication as described in | ||||
Section 4.3.6 of [RFC7231] and [RFC7235] MUST also be supported. | ||||
In addition, the HTTP CONNECT MUST include an indication of the | ||||
protocol being used with the HTTP CONNECT initiated tunnel as | ||||
described in [I-D.ietf-httpbis-tunnel-protocol] | ||||
3.5. Transport protocols implemented | 3.5. Transport protocols implemented | |||
For transport of media, secure RTP is used. The details of the | For transport of media, secure RTP is used. The details of the | |||
profile of RTP used are described in "RTP Usage" | profile of RTP used are described in "RTP Usage" | |||
[I-D.ietf-rtcweb-rtp-usage]. Key exchange MUST be done using DTLS- | [I-D.ietf-rtcweb-rtp-usage]. Key exchange MUST be done using DTLS- | |||
SRTP, as described in [I-D.ietf-rtcweb-security-arch]. | SRTP, as described in [I-D.ietf-rtcweb-security-arch]. | |||
For data transport over the WebRTC data channel | For data transport over the WebRTC data channel | |||
[I-D.ietf-rtcweb-data-channel], WebRTC endpoints MUST support SCTP | [I-D.ietf-rtcweb-data-channel], WebRTC implementations MUST support | |||
over DTLS over ICE. This encapsulation is specified in | SCTP over DTLS over ICE. This encapsulation is specified in | |||
[I-D.ietf-tsvwg-sctp-dtls-encaps]. Negotiation of this transport in | [I-D.ietf-tsvwg-sctp-dtls-encaps]. Negotiation of this transport in | |||
SDP is defined in [I-D.ietf-mmusic-sctp-sdp]. The SCTP extension for | SDP is defined in [I-D.ietf-mmusic-sctp-sdp]. The SCTP extension for | |||
NDATA, [I-D.ietf-tsvwg-sctp-ndata], MUST be supported. | NDATA, [I-D.ietf-tsvwg-sctp-ndata], MUST be supported. | |||
The setup protocol for WebRTC data channels is described in | The setup protocol for WebRTC data channels is described in | |||
[I-D.jesup-rtcweb-data-protocol]. | [I-D.ietf-rtcweb-data-protocol]. | |||
WebRTC devices MUST support multiplexing of DTLS and RTP over the | WebRTC implementations MUST support multiplexing of DTLS and RTP over | |||
same port pair, as described in the DTLS_SRTP specification | the same port pair, as described in the DTLS_SRTP specification | |||
[RFC5764], section 5.1.2. All application layer protocol payloads | [RFC5764], section 5.1.2. All application layer protocol payloads | |||
over this DTLS connection are SCTP packets. | over this DTLS connection are SCTP packets. | |||
Protocol identification MUST be supplied as part of the DTLS | Protocol identification MUST be supplied as part of the DTLS | |||
handshake, as specified in [I-D.thomson-rtcweb-alpn]. | handshake, as specified in [I-D.ietf-rtcweb-alpn]. | |||
4. Media Prioritization | 4. Media Prioritization | |||
The WebRTC prioritization model is that the application tells the | The WebRTC prioritization model is that the application tells the | |||
WebRTC browser about the priority of media and data flows through an | WebRTC implementation about the priority of media and data flows | |||
API. | through an API. | |||
The priority associated with a media or data flow is classified as | The priority associated with a media or data flow is classified as | |||
"normal", "below normal", "high" or "very high". There are only four | "normal", "below normal", "high" or "very high". There are only four | |||
priority levels at the API. | priority levels at the API. | |||
The priority settings affect two pieces of behavior: Packet markings | The priority settings affect two pieces of behavior: Packet markings | |||
and packet send sequence decisions. Each is described in its own | and packet send sequence decisions. Each is described in its own | |||
section below. | section below. | |||
4.1. Usage of Quality of Service - DSCP and Multiplexing | 4.1. Usage of Quality of Service - DSCP and Multiplexing | |||
WebRTC endpoints SHOULD attempt to set QoS on the packets sent, | Implementations SHOULD attempt to set QoS on the packets sent, | |||
according to the guidelines in [I-D.ietf-tsvwg-rtcweb-qos]. It is | according to the guidelines in [I-D.ietf-tsvwg-rtcweb-qos]. It is | |||
appropriate to depart from this recommendation when running on | appropriate to depart from this recommendation when running on | |||
platforms where QoS marking is not implemented. | platforms where QoS marking is not implemented. | |||
The WebRTC endpoint MAY turn off use of DSCP markings if it detects | The implementation MAY turn off use of DSCP markings if it detects | |||
symptoms of unexpected behaviour like priority inversion or blocking | symptoms of unexpected behaviour like priority inversion or blocking | |||
of packets with certain DSCP markings. The detection of these | of packets with certain DSCP markings. The detection of these | |||
conditions is implementation dependent. (Question: Does there need | conditions is implementation dependent. (Question: Does there need | |||
to be an API knob to turn off DSCP markings?) | to be an API knob to turn off DSCP markings?) | |||
All packets carrying data from the SCTP association supporting the | All packets arrying data from the SCTP association supporting the | |||
data channels MUST use a single DSCP code point. | data channels MUST use a single DSCP code point. | |||
All packets on one TCP connection, no matter what it carries, MUST | All packets on one TCP connection, no matter what it carries, MUST | |||
use a single DSCP code point. | use a single DSCP code point. | |||
More advice on the use of DSCP code points with RTP is given in | More advice on the use of DSCP code points with RTP is given in | |||
[I-D.ietf-dart-dscp-rtp]. | [I-D.ietf-dart-dscp-rtp]. | |||
There exist a number of schemes for achieving quality of service that | There exist a number of schemes for achieving quality of service that | |||
do not depend solely on DSCP code points. Some of these schemes | do not depend solely on DSCP code points. Some of these schemes | |||
skipping to change at page 7, line 48 | skipping to change at page 7, line 34 | |||
In each of the configurations mentioned, data channels may be carried | In each of the configurations mentioned, data channels may be carried | |||
in its own 5-tuple, or multiplexed together with one of the media | in its own 5-tuple, or multiplexed together with one of the media | |||
flows. | flows. | |||
More complex configurations, such as sending a high priority video | More complex configurations, such as sending a high priority video | |||
stream on one 5-tuple and sending all other video streams multiplexed | stream on one 5-tuple and sending all other video streams multiplexed | |||
together over another 5-tuple, can also be envisioned. More | together over another 5-tuple, can also be envisioned. More | |||
information on mapping media flows to 5-tuples can be found in | information on mapping media flows to 5-tuples can be found in | |||
[I-D.ietf-rtcweb-rtp-usage]. | [I-D.ietf-rtcweb-rtp-usage]. | |||
A sending WebRTC endpoint MUST be able to support the following | A sending implementation MUST be able to support the following | |||
configurations: | configurations: | |||
o multiplex all media and data on a single 5-tuple (fully bundled) | o multiplex all media and data on a single 5-tuple (fully bundled) | |||
o send each media stream on its own 5-tuple and data on its own | o send each media stream on its own 5-tuple and data on its own | |||
5-tuple (fully unbundled) | 5-tuple (fully unbundled) | |||
o bundle each media type (audio, video or data) into its own 5-tuple | It MAY choose to support other configurations, such as bundling each | |||
(bundling by media type) | media type (audio, video or data) into its own 5-tuple (bundling by | |||
media type). | ||||
It MAY choose to support other configurations. | ||||
Sending data over multiple 5-tuples is not supported. | Sending data over multiple 5-tuples is not supported. | |||
A receiving WebRTC endpoint MUST be able to receive media and data in | A receiving implementation MUST be able to receive media and data in | |||
all these configurations. | all these configurations. | |||
4.2. Local prioritization | 4.2. Local prioritization | |||
When an WebRTC endpoint has packets to send on multiple streams (with | When an WebRTC implementation has packets to send on multiple streams | |||
each media stream and each data channel considered as one "stream" | (with each media stream and each data channel considered as one | |||
for this purpose) that are congestion-controlled under the same | "stream" for this purpose) that are congestion-controlled under the | |||
congestion controller, the WebRTC endpoint SHOULD cause data to be | same congestion controller, the WebRTC implementation SHOULD cause | |||
emitted in such a way that each stream at each level of priority is | data to be emitted in such a way that each stream at each level of | |||
being given approximately twice the transmission capacity (measured | priority is being given approximately twice the transmission capacity | |||
in payload bytes) of the level below. | (measured in payload bytes) of the level below. | |||
Thus, when congestion occurs, a "very high" priority flow will have | Thus, when congestion occurs, a "very high" priority flow will have | |||
the ability to send 8 times as much data as a "below normal" flow if | the ability to send 8 times as much data as a "below normal" flow if | |||
both have data to send. This prioritization is independent of the | both have data to send. This prioritization is independent of the | |||
media type. The details of which packet to send first are | media type. The details of which packet to send first are | |||
implementation defined. | implementation defined. | |||
For example: If there is a very high priority audio flow sending 100 | For example: If there is a very high priority audio flow sending 100 | |||
byte packets, and a normal priority video flow sending 1000 byte | byte packets, and a normal priority video flow sending 1000 byte | |||
packets, and outgoing capacity exists for sending >5000 payload | packets, and outgoing capacity exists for sending >5000 payload | |||
skipping to change at page 9, line 51 | skipping to change at page 9, line 38 | |||
Eduardo Gueiros, Magnus Westerlund, Markus Isomaki and Dan Wing; the | Eduardo Gueiros, Magnus Westerlund, Markus Isomaki and Dan Wing; the | |||
contributions from Andrew Hutton also deserve special mention. | contributions from Andrew Hutton also deserve special mention. | |||
8. References | 8. References | |||
8.1. Normative References | 8.1. Normative References | |||
[I-D.ietf-httpbis-tunnel-protocol] | [I-D.ietf-httpbis-tunnel-protocol] | |||
Hutton, A., Uberti, J., and M. Thomson, "The Tunnel- | Hutton, A., Uberti, J., and M. Thomson, "The Tunnel- | |||
Protocol HTTP Request Header Field", draft-ietf-httpbis- | Protocol HTTP Request Header Field", draft-ietf-httpbis- | |||
tunnel-protocol-00 (work in progress), August 2014. | tunnel-protocol-01 (work in progress), January 2015. | |||
[I-D.ietf-mmusic-sctp-sdp] | [I-D.ietf-mmusic-sctp-sdp] | |||
Loreto, S. and G. Camarillo, "Stream Control Transmission | Holmberg, C., Loreto, S., and G. Camarillo, "Stream | |||
Protocol (SCTP)-Based Media Transport in the Session | Control Transmission Protocol (SCTP)-Based Media Transport | |||
Description Protocol (SDP)", draft-ietf-mmusic-sctp-sdp-07 | in the Session Description Protocol (SDP)", draft-ietf- | |||
(work in progress), July 2014. | mmusic-sctp-sdp-12 (work in progress), January 2015. | |||
[I-D.ietf-rtcweb-alpn] | ||||
Thomson, M., "Application Layer Protocol Negotiation for | ||||
Web Real-Time Communications (WebRTC)", draft-ietf-rtcweb- | ||||
alpn-00 (work in progress), July 2014. | ||||
[I-D.ietf-rtcweb-data-channel] | [I-D.ietf-rtcweb-data-channel] | |||
Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data | Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data | |||
Channels", draft-ietf-rtcweb-data-channel-11 (work in | Channels", draft-ietf-rtcweb-data-channel-13 (work in | |||
progress), July 2014. | progress), January 2015. | |||
[I-D.ietf-rtcweb-rtp-usage] | [I-D.ietf-rtcweb-rtp-usage] | |||
Perkins, C., Westerlund, M., and J. Ott, "Web Real-Time | Perkins, C., Westerlund, M., and J. Ott, "Web Real-Time | |||
Communication (WebRTC): Media Transport and Use of RTP", | Communication (WebRTC): Media Transport and Use of RTP", | |||
draft-ietf-rtcweb-rtp-usage-15 (work in progress), May | draft-ietf-rtcweb-rtp-usage-22 (work in progress), | |||
2014. | February 2015. | |||
[I-D.ietf-rtcweb-security] | [I-D.ietf-rtcweb-security] | |||
Rescorla, E., "Security Considerations for WebRTC", draft- | Rescorla, E., "Security Considerations for WebRTC", draft- | |||
ietf-rtcweb-security-07 (work in progress), July 2014. | ietf-rtcweb-security-07 (work in progress), July 2014. | |||
[I-D.ietf-rtcweb-security-arch] | [I-D.ietf-rtcweb-security-arch] | |||
Rescorla, E., "WebRTC Security Architecture", draft-ietf- | Rescorla, E., "WebRTC Security Architecture", draft-ietf- | |||
rtcweb-security-arch-10 (work in progress), July 2014. | rtcweb-security-arch-10 (work in progress), July 2014. | |||
[I-D.ietf-tsvwg-rtcweb-qos] | [I-D.ietf-tsvwg-rtcweb-qos] | |||
Dhesikan, S., Jennings, C., Druta, D., Jones, P., and J. | Dhesikan, S., Jennings, C., Druta, D., Jones, P., and J. | |||
Polk, "DSCP and other packet markings for RTCWeb QoS", | Polk, "DSCP and other packet markings for RTCWeb QoS", | |||
draft-ietf-tsvwg-rtcweb-qos-02 (work in progress), June | draft-ietf-tsvwg-rtcweb-qos-03 (work in progress), | |||
2014. | November 2014. | |||
[I-D.ietf-tsvwg-sctp-dtls-encaps] | [I-D.ietf-tsvwg-sctp-dtls-encaps] | |||
Tuexen, M., Stewart, R., Jesup, R., and S. Loreto, "DTLS | Tuexen, M., Stewart, R., Jesup, R., and S. Loreto, "DTLS | |||
Encapsulation of SCTP Packets", draft-ietf-tsvwg-sctp- | Encapsulation of SCTP Packets", draft-ietf-tsvwg-sctp- | |||
dtls-encaps-05 (work in progress), July 2014. | dtls-encaps-09 (work in progress), January 2015. | |||
[I-D.ietf-tsvwg-sctp-ndata] | [I-D.ietf-tsvwg-sctp-ndata] | |||
Stewart, R., Tuexen, M., Loreto, S., and R. Seggelmann, | Stewart, R., Tuexen, M., Loreto, S., and R. Seggelmann, | |||
"Stream Schedulers and a New Data Chunk for the Stream | "Stream Schedulers and a New Data Chunk for the Stream | |||
Control Transmission Protocol", draft-ietf-tsvwg-sctp- | Control Transmission Protocol", draft-ietf-tsvwg-sctp- | |||
ndata-01 (work in progress), July 2014. | ndata-02 (work in progress), January 2015. | |||
[I-D.reddy-mmusic-ice-happy-eyeballs] | ||||
Reddy, T., Patil, P., and P. Martinsen, "Happy Eyeballs | ||||
Extension for ICE", draft-reddy-mmusic-ice-happy- | ||||
eyeballs-07 (work in progress), June 2014. | ||||
[I-D.thomson-rtcweb-alpn] | [I-D.martinsen-mmusic-ice-dualstack-fairness] | |||
Thomson, M., "Application Layer Protocol Negotiation for | Martinsen, P., Reddy, T., and P. Patil, "ICE IPv4/IPv6 | |||
Web Real-Time Communications (WebRTC)", draft-thomson- | Dual Stack Fairness", draft-martinsen-mmusic-ice- | |||
rtcweb-alpn-00 (work in progress), April 2014. | dualstack-fairness-02 (work in progress), February 2015. | |||
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | |||
Requirement Levels", BCP 14, RFC 2119, March 1997. | Requirement Levels", BCP 14, RFC 2119, March 1997. | |||
[RFC4571] Lazzaro, J., "Framing Real-time Transport Protocol (RTP) | [RFC4571] Lazzaro, J., "Framing Real-time Transport Protocol (RTP) | |||
and RTP Control Protocol (RTCP) Packets over Connection- | and RTP Control Protocol (RTCP) Packets over Connection- | |||
Oriented Transport", RFC 4571, July 2006. | Oriented Transport", RFC 4571, July 2006. | |||
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy | [RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy | |||
Extensions for Stateless Address Autoconfiguration in | Extensions for Stateless Address Autoconfiguration in | |||
skipping to change at page 12, line 5 | skipping to change at page 11, line 42 | |||
6156, April 2011. | 6156, April 2011. | |||
[RFC6544] Rosenberg, J., Keranen, A., Lowekamp, B., and A. Roach, | [RFC6544] Rosenberg, J., Keranen, A., Lowekamp, B., and A. Roach, | |||
"TCP Candidates with Interactive Connectivity | "TCP Candidates with Interactive Connectivity | |||
Establishment (ICE)", RFC 6544, March 2012. | Establishment (ICE)", RFC 6544, March 2012. | |||
[RFC6724] Thaler, D., Draves, R., Matsumoto, A., and T. Chown, | [RFC6724] Thaler, D., Draves, R., Matsumoto, A., and T. Chown, | |||
"Default Address Selection for Internet Protocol Version 6 | "Default Address Selection for Internet Protocol Version 6 | |||
(IPv6)", RFC 6724, September 2012. | (IPv6)", RFC 6724, September 2012. | |||
[RFC7231] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol | ||||
(HTTP/1.1): Semantics and Content", RFC 7231, June 2014. | ||||
[RFC7235] Fielding, R. and J. Reschke, "Hypertext Transfer Protocol | ||||
(HTTP/1.1): Authentication", RFC 7235, June 2014. | ||||
8.2. Informative References | 8.2. Informative References | |||
[I-D.ietf-dart-dscp-rtp] | [I-D.ietf-dart-dscp-rtp] | |||
Black, D. and P. Jones, "Differentiated Services | Black, D. and P. Jones, "Differentiated Services | |||
(DiffServ) and Real-time Communication", draft-ietf-dart- | (DiffServ) and Real-time Communication", draft-ietf-dart- | |||
dscp-rtp-08 (work in progress), October 2014. | dscp-rtp-10 (work in progress), November 2014. | |||
[I-D.ietf-rtcweb-data-protocol] | ||||
Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data Channel | ||||
Establishment Protocol", draft-ietf-rtcweb-data- | ||||
protocol-09 (work in progress), January 2015. | ||||
[I-D.ietf-rtcweb-overview] | [I-D.ietf-rtcweb-overview] | |||
Alvestrand, H., "Overview: Real Time Protocols for | Alvestrand, H., "Overview: Real Time Protocols for | |||
Browser-based Applications", draft-ietf-rtcweb-overview-10 | Browser-based Applications", draft-ietf-rtcweb-overview-13 | |||
(work in progress), June 2014. | (work in progress), November 2014. | |||
[I-D.jesup-rtcweb-data-protocol] | ||||
Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data Channel | ||||
Protocol", draft-jesup-rtcweb-data-protocol-04 (work in | ||||
progress), February 2013. | ||||
[RFC3484] Draves, R., "Default Address Selection for Internet | [RFC3484] Draves, R., "Default Address Selection for Internet | |||
Protocol version 6 (IPv6)", RFC 3484, February 2003. | Protocol version 6 (IPv6)", RFC 3484, February 2003. | |||
[RFC5014] Nordmark, E., Chakrabarti, S., and J. Laganier, "IPv6 | [RFC5014] Nordmark, E., Chakrabarti, S., and J. Laganier, "IPv6 | |||
Socket API for Source Address Selection", RFC 5014, | Socket API for Source Address Selection", RFC 5014, | |||
September 2007. | September 2007. | |||
[RFC5128] Srisuresh, P., Ford, B., and D. Kegel, "State of Peer-to- | [RFC5128] Srisuresh, P., Ford, B., and D. Kegel, "State of Peer-to- | |||
Peer (P2P) Communication across Network Address | Peer (P2P) Communication across Network Address | |||
skipping to change at page 14, line 46 | skipping to change at page 14, line 25 | |||
o Added reference to the ALPN header (being adopted by RTCWEB) | o Added reference to the ALPN header (being adopted by RTCWEB) | |||
o Added reference to the DART RTP document | o Added reference to the DART RTP document | |||
o Said explicitly that SCTP for data channels has a single DSCP | o Said explicitly that SCTP for data channels has a single DSCP | |||
codepoint | codepoint | |||
A.7. Changes from -06 to -07 | A.7. Changes from -06 to -07 | |||
o Updated terminology in accordance with -overview. Got rid of all | o Updated references | |||
occurences of "WebRTC implementation". | ||||
o Modified description of ICE-TCP encapsulation in accordance with | o Removed reference to draft-hutton-rtcweb-nat-firewall- | |||
list discussion. | considerations | |||
o Added HTTP CONNECT requirement in accordance with list discussion. | A.8. Changes from -07 to -08 | |||
o Updated references | ||||
o Deleted "bundle each media type (audio, video or data) into its | ||||
own 5-tuple (bundling by media type)" from MUST support | ||||
configuration, since JSEP does not have a means to negotiate this | ||||
configuration | ||||
Author's Address | Author's Address | |||
Harald Alvestrand | Harald Alvestrand | |||
Email: harald@alvestrand.no | Email: harald@alvestrand.no | |||
End of changes. 46 change blocks. | ||||
110 lines changed or deleted | 94 lines changed or added | |||
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