--- 1/draft-ietf-rtcweb-overview-05.txt 2013-02-21 03:24:02.103753552 +0100 +++ 2/draft-ietf-rtcweb-overview-06.txt 2013-02-21 03:24:02.139755210 +0100 @@ -1,109 +1,104 @@ Network Working Group H. Alvestrand Internet-Draft Google -Intended status: Standards Track December 14, 2012 -Expires: June 17, 2013 +Intended status: Standards Track February 20, 2013 +Expires: August 24, 2013 Overview: Real Time Protocols for Brower-based Applications - draft-ietf-rtcweb-overview-05 + draft-ietf-rtcweb-overview-06 Abstract This document gives an overview and context of a protocol suite intended for use with real-time applications that can be deployed in browsers - "real time communication on the Web". It intends to serve as a starting and coordination point to make sure all the parts that are needed to achieve this goal are findable, and that the parts that belong in the Internet protocol suite are fully specified and on the right publication track. This document is a work item of the RTCWEB working group. -Requirements Language - - The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", - "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this - document are to be interpreted as described in RFC 2119 [RFC2119]. - 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 http://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 June 17, 2013. + This Internet-Draft will expire on August 24, 2013. Copyright Notice - Copyright (c) 2012 IETF Trust and the persons identified as the + Copyright (c) 2013 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 (http://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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents - 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 2. Principles and Terminology . . . . . . . . . . . . . . . . . . 5 - 2.1. Goals of this document . . . . . . . . . . . . . . . . . . 5 - 2.2. Relationship between API and protocol . . . . . . . . . . 5 - 2.3. On interoperability and innovation . . . . . . . . . . . . 6 - 2.4. Terminology . . . . . . . . . . . . . . . . . . . . . . . 7 - 3. Architecture and Functionality groups . . . . . . . . . . . . 8 - 4. Data transport . . . . . . . . . . . . . . . . . . . . . . . . 12 - 5. Data framing and securing . . . . . . . . . . . . . . . . . . 13 - 6. Data formats . . . . . . . . . . . . . . . . . . . . . . . . . 13 - 7. Connection management . . . . . . . . . . . . . . . . . . . . 13 - 8. Presentation and control . . . . . . . . . . . . . . . . . . . 14 - 9. Local system support functions . . . . . . . . . . . . . . . . 14 - 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 - 11. Security Considerations . . . . . . . . . . . . . . . . . . . 15 - 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16 - 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 - 13.1. Normative References . . . . . . . . . . . . . . . . . . . 16 - 13.2. Informative References . . . . . . . . . . . . . . . . . . 18 - Appendix A. Transport and Middlebox specification . . . . . . . . 19 - A.1. System-provided interfaces . . . . . . . . . . . . . . . . 19 - A.2. Middle box related functions . . . . . . . . . . . . . . . 19 - A.3. Transport protocols implemented . . . . . . . . . . . . . 20 - Appendix B. Change log . . . . . . . . . . . . . . . . . . . . . 20 + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 + 2. Principles and Terminology . . . . . . . . . . . . . . . . . . 4 + 2.1. Goals of this document . . . . . . . . . . . . . . . . . . 4 + 2.2. Relationship between API and protocol . . . . . . . . . . 4 + 2.3. On interoperability and innovation . . . . . . . . . . . . 5 + 2.4. Terminology . . . . . . . . . . . . . . . . . . . . . . . 6 + 3. Architecture and Functionality groups . . . . . . . . . . . . 7 + 4. Data transport . . . . . . . . . . . . . . . . . . . . . . . . 11 + 5. Data framing and securing . . . . . . . . . . . . . . . . . . 12 + 6. Data formats . . . . . . . . . . . . . . . . . . . . . . . . . 12 + 7. Connection management . . . . . . . . . . . . . . . . . . . . 12 + 8. Presentation and control . . . . . . . . . . . . . . . . . . . 13 + 9. Local system support functions . . . . . . . . . . . . . . . . 13 + 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 + 11. Security Considerations . . . . . . . . . . . . . . . . . . . 14 + 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15 + 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 + 13.1. Normative References . . . . . . . . . . . . . . . . . . . 15 + 13.2. Informative References . . . . . . . . . . . . . . . . . . 17 + Appendix A. Transport and Middlebox specification . . . . . . . . 18 + A.1. System-provided interfaces . . . . . . . . . . . . . . . . 18 + A.2. Middle box related functions . . . . . . . . . . . . . . . 18 + A.3. Transport protocols implemented . . . . . . . . . . . . . 19 + Appendix B. Change log . . . . . . . . . . . . . . . . . . . . . 19 B.1. Changes from - draft-alvestrand-dispatch-rtcweb-datagram-00 to -01 . . . 20 + draft-alvestrand-dispatch-rtcweb-datagram-00 to -01 . . . 19 B.2. Changes from draft-alvestrand-dispatch-01 to - draft-alvestrand-rtcweb-overview-00 . . . . . . . . . . . 20 - B.3. Changes from draft-alvestrand-rtcweb-00 to -01 . . . . . . 20 + draft-alvestrand-rtcweb-overview-00 . . . . . . . . . . . 19 + B.3. Changes from draft-alvestrand-rtcweb-00 to -01 . . . . . . 19 B.4. Changes from draft-alvestrand-rtcweb-overview-01 to - draft-ietf-rtcweb-overview-00 . . . . . . . . . . . . . . 21 - B.5. Changes from -00 to -01 of draft-ietf-rtcweb-overview . . 21 - B.6. Changes from -01 to -02 of draft-ietf-rtcweb-overview . . 21 - B.7. Changes from -02 to -03 of draft-ietf-rtcweb-overview . . 21 - B.8. Changes from -03 to -04 of draft-ietf-rtcweb-overview . . 22 - B.9. Changes from -04 to -05 of draft-ietf-rtcweb-overview . . 22 - Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 22 + draft-ietf-rtcweb-overview-00 . . . . . . . . . . . . . . 20 + B.5. Changes from -00 to -01 of draft-ietf-rtcweb-overview . . 20 + B.6. Changes from -01 to -02 of draft-ietf-rtcweb-overview . . 20 + B.7. Changes from -02 to -03 of draft-ietf-rtcweb-overview . . 20 + B.8. Changes from -03 to -04 of draft-ietf-rtcweb-overview . . 21 + B.9. Changes from -04 to -05 of draft-ietf-rtcweb-overview . . 21 + B.10. Changes from -05 to -06 . . . . . . . . . . . . . . . . . 21 + Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 21 1. Introduction The Internet was, from very early in its lifetime, considered a possible vehicle for the deployment of real-time, interactive applications - with the most easily imaginable being audio conversations (aka "Internet telephony") and video conferencing. The first attempts to build this were dependent on special networks, special hardware and custom-built software, often at very high prices @@ -172,21 +167,21 @@ possible to have all information needed to implement an RTCWEB compatible implementation. 2.2. Relationship between API and protocol The total RTCWEB/WEBRTC effort consists of two pieces: o A protocol specification, done in the IETF o A Javascript API specification, done in the W3C - [W3C.WD-webrtc-20120209] + [W3C.WD-webrtc-20120209][W3C.WD-mediacapture-streams-20120628] Together, these two specifications aim to provide an environment where Javascript embedded in any page, viewed in any compatible browser, when suitably authorized by its user, is able to set up communication using audio, video and auxiliary data, where the browser environment does not constrain the types of application in which this functionality can be used. The protocol specification does not assume that all implementations implement this API; it is not intended to be necessary for @@ -562,23 +557,24 @@ The most important part of control is the user's control over the browser's interaction with input/output devices and communications channels. It is important that the user have some way of figuring out where his audio, video or texting is being sent, for what purported reason, and what guarantees are made by the parties that form part of this control channel. This is largely a local function between the browser, the underlying operating system and the user interface; this is being worked on as part of the W3C API effort, and will be part of the peer connection API [W3C.WD-webrtc-20120209], and - the device control API [getusermedia]. Considerations for the - implications of wanting to identify correspondents are described in - [I-D.rescorla-rtcweb-generic-idp] (not a WG item). + the media capture API [W3C.WD-mediacapture-streams-20120628]. + Considerations for the implications of wanting to identify + correspondents are described in [I-D.rescorla-rtcweb-generic-idp] + (not a WG item). 9. Local system support functions These are characterized by the fact that the quality of these functions strongly influence the user experience, but the exact algorithm does not need coordination. In some cases (for instance echo cancellation, as described below), the overall system definition may need to specify that the overall system needs to have some characteristics for which these facilities are useful, without requiring them to be implemented a certain way. @@ -593,26 +589,25 @@ o Echo cancellation should be good enough to achieve the suppression of acoustical feedback loops below a perceptually noticeable level. o Privacy concerns must be satisfied; for instance, if remote control of camera is offered, the APIs should be available to let the local participant figure out who's controlling the camera, and possibly decide to revoke the permission for camera usage. o Automatic gain control, if present, should normalize a speaking - voice into + voice into a reasonable dB range. - The requirements on RTCWEB systems in this category are found in - ; the proposed API for - control of local devices are found in [getusermedia]. + The requirements on RTCWEB systems with regard to audio processing + are found in [I-D.ietf-rtcweb-audio]; the proposed API for control of + local devices are found in [W3C.WD-mediacapture-streams-20120628]. 10. IANA Considerations This document makes no request of IANA. Note to RFC Editor: this section may be removed on publication as an RFC. 11. Security Considerations @@ -647,81 +642,83 @@ does not mean that others' contributions are less important. Thanks to Cary Bran, Cullen Jennings, Colin Perkins, Magnus Westerlund and Joerg Ott, who offered technical contributions on various versions of the draft. Thanks to Jonathan Rosenberg, Matthew Kaufman and others at Skype for the ASCII drawings in section 1. Thanks to Eric Rescorla, Justin Uberti, Henry Sinnreich, Colin - Perkins and Simon Leinen for document review, ad to Heath Matlock for - grammatical review. + Perkins, Bjoern Hoehrmann and Simon Leinen for document review, and + to Heath Matlock for grammatical review. 13. References 13.1. Normative References [I-D.ietf-mmusic-sctp-sdp] Loreto, S. and G. Camarillo, "Stream Control Transmission Protocol (SCTP)-Based Media Transport in the Session - Description Protocol (SDP)", draft-ietf-mmusic-sctp-sdp-01 - (work in progress), March 2012. + Description Protocol (SDP)", draft-ietf-mmusic-sctp-sdp-03 + (work in progress), January 2013. + + [I-D.ietf-rtcweb-audio] + Valin, J. and C. Bran, "WebRTC Audio Codec and Processing + Requirements", draft-ietf-rtcweb-audio-01 (work in + progress), November 2012. [I-D.ietf-rtcweb-data-channel] Jesup, R., Loreto, S., and M. Tuexen, "RTCWeb Datagram - Connection", draft-ietf-rtcweb-data-channel-00 (work in - progress), March 2012. + Connection", draft-ietf-rtcweb-data-channel-02 (work in + progress), October 2012. [I-D.ietf-rtcweb-jsep] Uberti, J. and C. Jennings, "Javascript Session - Establishment Protocol", draft-ietf-rtcweb-jsep-01 (work - in progress), June 2012. + Establishment Protocol", draft-ietf-rtcweb-jsep-02 (work + in progress), October 2012. [I-D.ietf-rtcweb-rtp-usage] Perkins, C., Westerlund, M., and J. Ott, "Web Real-Time Communication (WebRTC): Media Transport and Use of RTP", - draft-ietf-rtcweb-rtp-usage-04 (work in progress), - July 2012. + draft-ietf-rtcweb-rtp-usage-05 (work in progress), + October 2012. [I-D.ietf-rtcweb-security] Rescorla, E., "Security Considerations for RTC-Web", - draft-ietf-rtcweb-security-03 (work in progress), - June 2012. + draft-ietf-rtcweb-security-04 (work in progress), + January 2013. [I-D.ietf-rtcweb-security-arch] Rescorla, E., "RTCWEB Security Architecture", - draft-ietf-rtcweb-security-arch-03 (work in progress), - July 2012. + draft-ietf-rtcweb-security-arch-06 (work in progress), + January 2013. [I-D.nandakumar-rtcweb-stun-uri] Nandakumar, S., Salgueiro, G., Jones, P., and M. Petit- Huguenin, "URI Scheme for Session Traversal Utilities for - NAT (STUN) Protocol", draft-nandakumar-rtcweb-stun-uri-01 - (work in progress), March 2012. + NAT (STUN) Protocol", draft-nandakumar-rtcweb-stun-uri-03 + (work in progress), January 2013. [I-D.tuexen-tsvwg-sctp-dtls-encaps] Jesup, R., Loreto, S., Stewart, R., and M. Tuexen, "DTLS Encapsulation of SCTP Packets for RTCWEB", draft-tuexen-tsvwg-sctp-dtls-encaps-01 (work in progress), July 2012. - [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate - Requirement Levels", BCP 14, RFC 2119, March 1997. - [RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model with Session Description Protocol (SDP)", RFC 3264, June 2002. [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. Jacobson, "RTP: A Transport Protocol for Real-Time - Applications", STD 64, RFC 3550, July 2003. + Applications", RFC 3550, July 2003. [RFC3711] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, "The Secure Real-time Transport Protocol (SRTP)", RFC 3711, March 2004. [RFC5245] Rosenberg, J., "Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal for Offer/Answer Protocols", RFC 5245, April 2010. @@ -733,107 +730,108 @@ [I-D.cbran-rtcweb-codec] Bran, C., Jennings, C., and J. Valin, "WebRTC Codec and Media Processing Requirements", draft-cbran-rtcweb-codec-02 (work in progress), March 2012. [I-D.ietf-rtcweb-use-cases-and-requirements] Holmberg, C., Hakansson, S., and G. Eriksson, "Web Real- Time Communication Use-cases and Requirements", - draft-ietf-rtcweb-use-cases-and-requirements-09 (work in - progress), June 2012. + draft-ietf-rtcweb-use-cases-and-requirements-10 (work in + progress), December 2012. [I-D.jesup-rtcweb-data-protocol] Jesup, R., Loreto, S., and M. Tuexen, "WebRTC Data Channel - Protocol", draft-jesup-rtcweb-data-protocol-02 (work in - progress), July 2012. + Protocol", draft-jesup-rtcweb-data-protocol-03 (work in + progress), September 2012. [I-D.rescorla-rtcweb-generic-idp] Rescorla, E., "RTCWEB Generic Identity Provider Interface", draft-rescorla-rtcweb-generic-idp-01 (work in progress), March 2012. [RFC3935] Alvestrand, H., "A Mission Statement for the IETF", BCP 95, RFC 3935, October 2004. [W3C.WD-html5-20110525] Hickson, I., "HTML5", World Wide Web Consortium LastCall WD-html5-20110525, May 2011, . + [W3C.WD-mediacapture-streams-20120628] + Burnett, D. and A. Narayanan, "Media Capture and Streams", + World Wide Web Consortium WD WD-mediacapture-streams- + 20120628, June 2012, . + [W3C.WD-webrtc-20120209] Bergkvist, A., Burnett, D., Narayanan, A., and C. Jennings, "WebRTC 1.0: Real-time Communication Between Browsers", World Wide Web Consortium WD WD-webrtc- 20120209, February 2012, . - [getusermedia] - Burnett, D. and A. Narayanan, "getusermedia: Getting - access to local devices that can generate multimedia - streams", December 2011, - . - Appendix A. Transport and Middlebox specification The draft referred to as "transport and middle boxes" in Section 4 has not been written yet. This appendix contains some keywords to what it should say; this also serves the purpose of linking to the drafts-in-progress that are relevant to this specification. A.1. System-provided interfaces The protocol specifications used here assume that the following protocols are available as system-level interfaces: o UDP. This is the protocol assumed by most protocol elements described. o TCP. This is used for HTTP/WebSockets, as well as for TURN/SSL and ICE-TCP. - For both protocols, we assume the ability to set the DSCP code point - of the sockets opened. We do not assume that the DSCP codepoints - will be honored, and we do assume that they may be zeroed or changed, - since this is a local configuration issue. + For both protocols, this specification assumes the ability to set the + DSCP code point of the sockets opened. It does not assume that the + DSCP codepoints will be honored, and does assume that they may be + zeroed or changed, since this is a local configuration issue. - We do not assume that the implementation will have access to ICMP or - raw IP. + This specification does not assume that the implementation will have + access to ICMP or raw IP. A.2. Middle box related functions The primary mechanism to deal with middle boxes is ICE, which is an appropriate way to deal with NAT boxes and firewalls that accept traffic from the inside, but only from the outside if it's in response to inside traffic (simple stateful firewalls). In order to deal with symmetric NATs, TURN MUST be supported. In order to deal with firewalls that block all UDP traffic, TURN over TCP MUST be supported. (QUESTION: What about ICE-TCP?) The following specifications MUST be supported: o ICE [RFC5245] o TURN, including TURN over TCP [[QUESTION: and TURN over TLS]], [RFC5766]. - For referring to ICE servers, we use the STUN URI, - [I-D.nandakumar-rtcweb-stun-uri]. + For referring to STUN and TURN servers, this specification depends on + the STUN URI, [I-D.nandakumar-rtcweb-stun-uri]. A.3. Transport protocols implemented - For data transport, we implement SCTP over DTLS over ICE. This is - specified in [I-D.tuexen-tsvwg-sctp-dtls-encaps]. Negotiation of - this transport in SCTP is defined in [I-D.ietf-mmusic-sctp-sdp]. + For data transport, RTCWEB implementations support SCTP over DTLS + over ICE. This is specified in [I-D.tuexen-tsvwg-sctp-dtls-encaps]. + Negotiation of this transport in SCTP is defined in + [I-D.ietf-mmusic-sctp-sdp]. Appendix B. Change log This section may be deleted by the RFC Editor when preparing for publication. B.1. Changes from draft-alvestrand-dispatch-rtcweb-datagram-00 to -01 Added section "On interoperability and innovation" @@ -924,19 +922,24 @@ Several wording changes in response to review comments from EKR Added Appendix A to hold references and notes that are not yet in a separate document. B.9. Changes from -04 to -05 of draft-ietf-rtcweb-overview Minor grammatical fixes. This is mainly a "keepalive" refresh. +B.10. Changes from -05 to -06 + + Clarifications in response to Last Call review comments. Inserted + reference to draft-ietf-rtcweb-audio. + Author's Address Harald T. Alvestrand Google Kungsbron 2 Stockholm, 11122 Sweden Email: harald@alvestrand.no