--- 1/draft-ietf-mmusic-sdp-mux-attributes-13.txt 2016-09-21 23:15:50.222525463 -0700 +++ 2/draft-ietf-mmusic-sdp-mux-attributes-14.txt 2016-09-21 23:15:50.422530219 -0700 @@ -1,18 +1,18 @@ Network Working Group S. Nandakumar Internet-Draft Cisco -Intended status: Standards Track June 27, 2016 -Expires: December 29, 2016 +Intended status: Standards Track September 22, 2016 +Expires: March 26, 2017 A Framework for SDP Attributes when Multiplexing - draft-ietf-mmusic-sdp-mux-attributes-13 + draft-ietf-mmusic-sdp-mux-attributes-14 Abstract The purpose of this specification is to provide a framework for analyzing the multiplexing characteristics of Session Description Protocol (SDP) attributes when SDP is used to negotiate the usage of single 5-tuple for sending and receiving media associated with multiple media descriptions. This specification also categorizes the existing SDP attributes based @@ -26,21 +26,21 @@ 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 December 29, 2016. + This Internet-Draft will expire on March 26, 2017. Copyright Notice Copyright (c) 2016 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 @@ -167,44 +167,44 @@ 14.2.1.2. Example: Attribute Capability Multiplexing . . . 68 14.3. RFC6871 Analysis . . . . . . . . . . . . . . . . . . . . 69 14.3.1. Recommendation: Dealing with Payload Type Numbers . 69 14.3.1.1. Example: Attribute Capability Under Shared Payload Type . . . . . . . . . . . . . . . . . . 69 14.3.2. Recommendation: Dealing with Latent Configurations . 70 15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 71 15.1. New 'Multiplexing Categories' subregistry . . . . . . . 71 15.2. 'Mux Category' column for subregistries . . . . . . . . 72 15.2.1. Table: SDP bwtype . . . . . . . . . . . . . . . . . 72 - 15.2.2. Table: att-field (session level) . . . . . . . . . . 72 + 15.2.2. Table: att-field (session level) . . . . . . . . . . 73 15.2.3. Table: att-field (both session and media level) . . 73 15.2.4. Table: att-field (media level only) . . . . . . . . 75 15.2.5. Table: att-field (source level) . . . . . . . . . . 78 15.2.6. Table: content SDP Parameters . . . . . . . . . . . 79 15.2.7. Table: Semantics for the 'group' SDP Attribute . . . 79 - 15.2.8. Table: 'rtcp-fb' Attribute Values . . . . . . . . . 79 + 15.2.8. Table: 'rtcp-fb' Attribute Values . . . . . . . . . 80 15.2.9. Table: 'ack' and 'nack' Attribute Values . . . . . . 80 15.2.10. Table: 'depend' SDP Attribute Values . . . . . . . . 80 15.2.11. Table: 'cs-correlation' Attribute Values . . . . . . 81 15.2.12. Table: Semantics for the 'ssrc-group' SDP Attribute 81 15.2.13. Table: SDP/RTSP key management protocol identifiers 81 15.2.14. Table: Codec Control Messages . . . . . . . . . . . 82 15.2.15. Table: QoS Mechanism Tokens . . . . . . . . . . . . 82 15.2.16. Table: SDP Capability Negotiation Option Tags . . . 82 15.2.17. Table: Timestamp Reference Clock Source Parameters . 83 15.2.18. Table: Media Clock Source Parameters . . . . . . . . 83 - 16. Security Considerations . . . . . . . . . . . . . . . . . . . 83 + 16. Security Considerations . . . . . . . . . . . . . . . . . . . 84 17. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 84 18. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 84 19. References . . . . . . . . . . . . . . . . . . . . . . . . . 87 19.1. Normative References . . . . . . . . . . . . . . . . . . 87 - 19.2. Informative References . . . . . . . . . . . . . . . . . 87 - Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 95 + 19.2. Informative References . . . . . . . . . . . . . . . . . 88 + Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 96 1. Introduction SDP defines several attributes for capturing characteristics that apply to the individual media descriptions (described by "m=" lines") and the overall multimedia session. Typically different media types (audio, video, etc.) described using different media descriptions represent separate RTP sessions that are carried over individual transport layer flows. However [I-D.ietf-mmusic-sdp-bundle-negotiation] defines a way to use a @@ -688,31 +688,28 @@ | | | | | +--------+---------------+-------+--------------+ 5.5 RFC4574 Attribute Analysis 5.6. RFC5432: QOS Mechanism Selection in SDP [RFC5432] defines procedures to negotiate QOS mechanisms using the SDP offer/answer model. - +----------------+----------------------------+-------+-------------+ - | Name | Notes | Level | Mux | - | | | | Category | - +----------------+----------------------------+-------+-------------+ - | qos-mech-send | Refer to section Section | B | TRANSPORT | - | | 10 | | | + +----------------+-----------------------+-------+--------------+ + | Name | Notes | Level | Mux Category | + +----------------+-----------------------+-------+--------------+ + | qos-mech-send | Refer to Section 10 | B | TRANSPORT | | | | | | - | qos-mech-recv | Refer to section Section | B | TRANSPORT | - | | 10 | | | + | qos-mech-recv | Refer to Section 10 | B | TRANSPORT | | | | | | - +----------------+----------------------------+-------+-------------+ + +----------------+-----------------------+-------+--------------+ 5.6 RFC5432 Attribute Analysis 5.7. RFC4568: SDP Security Descriptions [RFC4568] defines a SDP cryptographic attribute for unicast media streams. The attribute describes a cryptographic key and other parameters that serve to configure security for a unicast media stream in either a single message or a roundtrip exchange. @@ -3046,33 +3043,29 @@ configurations with multiplexed media. It is still allowed to use the latent configuration attribute, however the limitations above will apply. To determine valid combinations, actual negotiation will have to be attempted subsequently instead. 15. IANA Considerations [RFC EDITOR NOTE: Please replace RFCXXXX with the RFC number of this document.] - Section 15.1 defines a new subregistry for identifying the initial - registrations for various multiplexing categories applicable, as - proposed in this document. + Section 15.1 defines a new subregistry to be added by the IANA for + identifying the initial registrations for various multiplexing + categories applicable, as proposed in this document. - The IANA is requested to add a new column named "Mux Category" to + IANA is also requested to add a new column named "Mux Category" to several of the subregistries in the "Session Description Protocol (SDP) Parameters" registry. The tables in Section 15.2 identify name - of an entry in the existing subregistry and specify the value to put - in the new "Mux Category" column of the associated IANA registry. - Any entries in the existing tables that do not have a value for the - "Mux Category" specified in this RFC will get a value of "TBD". - Future specifications can change the "TBD" entries to the correct - value. + of an entry in the existing subregistry and specify the value to be + put in the new "Mux Category" column of the associated IANA registry. 15.1. New 'Multiplexing Categories' subregistry A new sub-registry needs to be defined called the "Multiplexing Categories", with the following registrations created initially: "NORMAL", "CAUTION", "IDENTICAL", "TRANSPORT", "SUM", "INHERIT", "IDENTICAL-PER-PT", "SPECIAL" and "TBD" as defined in this document. Initial value registration for "Multiplexing Categories". @@ -3082,37 +3075,54 @@ | NORMAL | RFCXXXX | | CAUTION | RFCXXXX | | IDENTICAL | RFCXXXX | | TRANSPORT | RFCXXXX | | SUM | RFCXXXX | | INHERIT | RFCXXXX | | IDENTICAL-PER-PT | RFCXXXX | | SPECIAL | RFCXXXX | | TBD | RFCXXXX | +-------------------------+-----------+ - Further entries can be registered on a first-come first-serve basis. + + Further entries can be registered using Standard Actions policies + outlined in [RFC5226], which requires IESG review and approval and + standards-track IETF RFC publication. + Each registration needs to indicate the multiplexing category value to be added to the "Multiplexing Categories" subregistry as defined in this section. Such a registration MUST also indicate the applicability of the newly defined multiplexing category value to various subregistries defined - at "Session Description Protocol (SDP) Parameters". + at the "Session Description Protocol (SDP) Parameters" registry. 15.2. 'Mux Category' column for subregistries Each sub-section identifies a subregistry in the "Session Description Protocol (SDP) Parameters" registry. The tables list the column that identifies the SDP attribute name/Token/Value from the corresponding subregistries and the values to be used for the new "Mux Category" column to be added. + For the entries in the existing subregistries, under the "Session + Description Protocol (SDP) Parameters" registry, that lack a value + for the "Mux Category" in this specification will get a value of + "TBD". + + Any future updates to the "Mux Category" column values needs to + follow the existing registration policy of the affected table + (Section 8.2.4.2 of [I-D.ietf-mmusic-rfc4566bis]). + + Also, the procedures from Section 8.2.4.1 of + [I-D.ietf-mmusic-rfc4566bis] needs to be followed when assigning "Mux + Category" value for the newly defined SDP attributes. + 15.2.1. Table: SDP bwtype The following values are to be added to the 'SDP bwtype' subregistry in the "Session Description Protocol (SDP) Parameters" registry. The references should be updated to point at this RFC as well as the previous references. +----------+--------------+ | SDP Name | Mux Category | +----------+--------------+ @@ -3629,26 +3639,29 @@ | Name | Mux Category | +-----------+--------------+ | sender | NORMAL | | direct | NORMAL | | IEEE1722 | NORMAL | +-----------+--------------+ 16. Security Considerations This document does not add any new security considerations beyond the - existing considerations in the RFCs for protocols that are being - multiplexed together. + existing considerations in the RTP RFCs ([RFC3550] and [RFC3711]) + that are referenced by this specification. - The ways that SRTP streams are keyed is not believed to create any - two-time pad vulnerability for the currently defined SRTP keying - mechanism. + The primary security for RTP including the way it is used here is + described in [RFC3550] and [RFC3711]. + + When multiplexing SDP attributes with the category "CAUTION", the + implementations should be aware of possible issues as described in + this specification. 17. Acknowledgments I would like to thank Cullen Jennings, Flemming Andreasen for suggesting the categories, contributing text and reviewing the draft. I would also link to thank Magnus Westerlund, Christer Holmberg, Jonathan Lennox, Bo Burman, Ari Keranen, and Dan Wing on suggesting structural changes helping improve the document readability. I would like also to thank following experts on their inputs and @@ -3660,26 +3673,29 @@ Evens(5.12,5.27,8.4), Subha Dhesikan(5.6,10), Dan Wing(5.7,5.12,5.35,5.39,5.45), Cullen Jennings (5.40), Ali C Begen(5.1,5.20,5.22,5.25,5.38,7.3,8.2,8.4,8.6,9.2,13.1), Bo Burman (7.2,7.6), Charles Eckel(5.15,5.27,5.28,9.1,8.5), Paul Kyzivat(5.24), Ian Johansson(5.15), Saravanan Shanmugham(5.11), Paul E Jones(5.30), Rajesh Kumar(5.48), Jonathan Lennox(5.36,5,15,9.1,11.1), Mo Zanaty(5.4,5.5,5.23,8.1,8.3,8.5,12.1), Christian Huitema (5.14), Qin Wu (5.47 PM-Dir review), Hans Stokking(5.43,5.16), Christian Groves (5.48,5.55), Thomas Stach. + I would like to thank Chris Lonvick for the SECDIR review, Dan + Romascanu for th Gen-ART review and Sabrina Tanamal for the IANA + review. + Thanks to Ben Campbell for AD review suggestions. 18. Change Log [RFC EDITOR NOTE: Please remove this section when publishing] - Changes from draft-ietf-mmusic-sdp-mux-attributes-10 - draft-ietf- mmusic-sdp-mux-attributes-13 o Incorporated Comments from WGLC review and AD Evaluation Changes from draft-ietf-mmusic-sdp-mux-attributes-10 o Incorporated Comments from Bo Burman for publication request Changes from draft-ietf-mmusic-sdp-mux-attributes-08 to draft-ietf- @@ -3806,33 +3823,43 @@ o Updated IANA Consideration Section. Changes from draft-nandakumar-mmusic-mux-attributes-00 o Added new section for dealing with FEC payload types. 19. References 19.1. Normative References + [I-D.ietf-mmusic-rfc4566bis] + Handley, M., Jacobson, V., Perkins, C., and A. Begen, + "SDP: Session Description Protocol", draft-ietf-mmusic- + rfc4566bis-17 (work in progress), June 2016. + [I-D.ietf-mmusic-sdp-bundle-negotiation] Holmberg, C., Alvestrand, H., and C. Jennings, "Negotiating Media Multiplexing Using the Session Description Protocol (SDP)", draft-ietf-mmusic-sdp-bundle- negotiation-24 (work in progress), January 2016. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session Description Protocol", RFC 4566, DOI 10.17487/RFC4566, July 2006, . + [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an + IANA Considerations Section in RFCs", BCP 26, RFC 5226, + DOI 10.17487/RFC5226, May 2008, + . + 19.2. Informative References [H.248.15] "Gateway control protocol: SDP H.248 package attribute", . [IANA] "Session Description Protocol (SDP) Parameters", . @@ -3887,35 +3914,45 @@ [RFC3407] Andreasen, F., "Session Description Protocol (SDP) Simple Capability Declaration", RFC 3407, DOI 10.17487/RFC3407, October 2002, . [RFC3524] Camarillo, G. and A. Monrad, "Mapping of Media Streams to Resource Reservation Flows", RFC 3524, DOI 10.17487/ RFC3524, April 2003, . + [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. + Jacobson, "RTP: A Transport Protocol for Real-Time + Applications", STD 64, RFC 3550, DOI 10.17487/RFC3550, + July 2003, . + [RFC3556] Casner, S., "Session Description Protocol (SDP) Bandwidth Modifiers for RTP Control Protocol (RTCP) Bandwidth", RFC 3556, DOI 10.17487/RFC3556, July 2003, . [RFC3605] Huitema, C., "Real Time Control Protocol (RTCP) attribute in Session Description Protocol (SDP)", RFC 3605, DOI 10.17487/RFC3605, October 2003, . [RFC3611] Friedman, T., Ed., Caceres, R., Ed., and A. Clark, Ed., "RTP Control Protocol Extended Reports (RTCP XR)", RFC 3611, DOI 10.17487/RFC3611, November 2003, . + [RFC3711] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. + Norrman, "The Secure Real-time Transport Protocol (SRTP)", + RFC 3711, DOI 10.17487/RFC3711, March 2004, + . + [RFC3890] Westerlund, M., "A Transport Independent Bandwidth Modifier for the Session Description Protocol (SDP)", RFC 3890, DOI 10.17487/RFC3890, September 2004, . [RFC4091] Camarillo, G. and J. Rosenberg, "The Alternative Network Address Types (ANAT) Semantics for the Session Description Protocol (SDP) Grouping Framework", RFC 4091, DOI 10.17487/RFC4091, June 2005, .