draft-ietf-mmusic-rfc4566bis-33.txt   draft-ietf-mmusic-rfc4566bis-34.txt 
Network Working Group A. Begen Network Working Group A. Begen
Internet-Draft Networked Media Internet-Draft Networked Media
Obsoletes: 4566 (if approved) P. Kyzivat Obsoletes: 4566 (if approved) P. Kyzivat
Intended status: Standards Track Intended status: Standards Track
Expires: August 26, 2019 C. Perkins Expires: September 22, 2019 C. Perkins
University of Glasgow University of Glasgow
M. Handley M. Handley
UCL UCL
February 22, 2019 March 21, 2019
SDP: Session Description Protocol SDP: Session Description Protocol
draft-ietf-mmusic-rfc4566bis-33 draft-ietf-mmusic-rfc4566bis-34
Abstract Abstract
This memo defines the Session Description Protocol (SDP). SDP is This memo defines the Session Description Protocol (SDP). SDP is
intended for describing multimedia sessions for the purposes of intended for describing multimedia sessions for the purposes of
session announcement, session invitation, and other forms of session announcement, session invitation, and other forms of
multimedia session initiation. This document obsoletes RFC 4566. multimedia session initiation. This document obsoletes RFC 4566.
Status of This Memo Status of This Memo
skipping to change at page 1, line 38 skipping to change at page 1, line 38
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 https://datatracker.ietf.org/drafts/current/. Drafts is at https://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 August 26, 2019. This Internet-Draft will expire on September 22, 2019.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 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
(https://trustee.ietf.org/license-info) in effect on the date of (https://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
skipping to change at page 10, line 42 skipping to change at page 10, line 42
b=* (zero or more bandwidth information lines) b=* (zero or more bandwidth information lines)
k=* (encryption key) k=* (encryption key)
a=* (zero or more media attribute lines) a=* (zero or more media attribute lines)
The set of type letters is deliberately small and not intended to be The set of type letters is deliberately small and not intended to be
extensible -- an SDP parser MUST completely ignore any session extensible -- an SDP parser MUST completely ignore any session
description that contains a type letter that it does not understand. description that contains a type letter that it does not understand.
The attribute mechanism ("a=" described below) is the primary means The attribute mechanism ("a=" described below) is the primary means
for extending SDP and tailoring it to particular applications or for extending SDP and tailoring it to particular applications or
media. Some attributes (the ones listed in Section 6 of this memo) media. Some attributes (the ones listed in Section 6 of this memo)
have a defined meaning, but others may be added on a media-, or have a defined meaning, but others may be added on a media- or
session-specific basis. (Attribute scopes in addition to media- and session-specific basis. (Attribute scopes in addition to media- and
session- specific may also be defined in extensions to this document. session- specific may also be defined in extensions to this document.
E.g., [RFC5576], [I-D.ietf-mmusic-data-channel-sdpneg].) An SDP E.g., [RFC5576], [I-D.ietf-mmusic-data-channel-sdpneg].) An SDP
parser MUST ignore any attribute it doesn't understand. parser MUST ignore any attribute it doesn't understand.
An SDP description may contain URIs that reference external content An SDP description may contain URIs that reference external content
in the "u=", "k=", and "a=" lines. These URIs may be dereferenced in in the "u=", "k=", and "a=" lines. These URIs may be dereferenced in
some cases, making the session description non-self-contained. some cases, making the session description non-self-contained.
The connection ("c=") information in the session-level section The connection ("c=") information in the session-level section
skipping to change at page 30, line 43 skipping to change at page 30, line 43
Usage Level: session, media Usage Level: session, media
Charset Dependent: no Charset Dependent: no
Example: Example:
a=recvonly a=recvonly
This specifies that the tools should be started in receive-only mode This specifies that the tools should be started in receive-only mode
where applicable. Note that recvonly applies to the media only, not where applicable. Note that recvonly applies to the media only, not
to any associated control protocol (e.g., an RTP-based system in to any associated control protocol. An RTP-based system in recvonly
recvonly mode should still send RTCP packets). mode MUST still send RTCP packets as described in [RFC3550]
Section 6.
6.7.2. sendrecv (send-receive) 6.7.2. sendrecv (send-receive)
Name: sendrecv Name: sendrecv
Value: Value:
Usage Level: session, media Usage Level: session, media
Charset Dependent: no Charset Dependent: no
Example: Example:
a=sendrecv a=sendrecv
This specifies that the tools should be started in send and receive This specifies that the tools should be started in send and receive
mode. This is necessary for interactive multimedia conferences with mode. This is necessary for interactive multimedia conferences with
tools that default to receive-only mode. tools that default to receive-only mode.
skipping to change at page 54, line 45 skipping to change at page 54, line 45
o Identified now-obsolete items: "a=cat", "a=keywds", "k=". o Identified now-obsolete items: "a=cat", "a=keywds", "k=".
o Updated normative and informative references, and added references o Updated normative and informative references, and added references
to additional relevant related RFCs. to additional relevant related RFCs.
o Reformatted the SDP Attributes section for readability. The o Reformatted the SDP Attributes section for readability. The
syntax of attribute values is now given in ABNF. syntax of attribute values is now given in ABNF.
o Made mandatory the sending of RTCP with inactive media streams. o Made mandatory the sending of RTCP with inactive media streams.
o Removed the section "Private Sessions". That section dates back
to a time when the primary use of SDP was with SAP (Session
Announcement Protocol). That has fallen out of use. Now the vast
majority of uses of SDP is for establishment of private sessions.
The considerations for that are covered in Section 7.
o Expanded and clarified the specification of the "lang" and o Expanded and clarified the specification of the "lang" and
"sdplang" attributes. "sdplang" attributes.
o Removed some references to SAP because it is no longer in o Removed some references to SAP because it is no longer in
widespread use. widespread use.
o Changed the way <fmt> values for UDP transport are registered. o Changed the way <fmt> values for UDP transport are registered.
o Changed the mechanism and documentation required for registering o Changed the mechanism and documentation required for registering
new attributes. new attributes.
skipping to change at page 56, line 14 skipping to change at page 56, line 18
12. References 12. References
12.1. Normative References 12.1. Normative References
[E164] International Telecommunication Union, "E.164 : The [E164] International Telecommunication Union, "E.164 : The
international public telecommunication numbering plan", international public telecommunication numbering plan",
ITU Recommendation E.164, November 2010. ITU Recommendation E.164, November 2010.
[I-D.ietf-mmusic-data-channel-sdpneg] [I-D.ietf-mmusic-data-channel-sdpneg]
Drage, K., Makaraju, M., Stoetzer-Bradler, J., Ejzak, R., Drage, K., Makaraju, M., Ejzak, R., Marcon, J., and R.
Marcon, J., and R. Even, "SDP-based Data Channel Even, "SDP-based Data Channel Negotiation", draft-ietf-
Negotiation", draft-ietf-mmusic-data-channel-sdpneg-23 mmusic-data-channel-sdpneg-25 (work in progress), March
(work in progress), January 2019. 2019.
[I-D.ietf-mmusic-sdp-mux-attributes] [I-D.ietf-mmusic-sdp-mux-attributes]
Nandakumar, S., "A Framework for SDP Attributes when Nandakumar, S., "A Framework for SDP Attributes when
Multiplexing", draft-ietf-mmusic-sdp-mux-attributes-17 Multiplexing", draft-ietf-mmusic-sdp-mux-attributes-17
(work in progress), February 2018. (work in progress), February 2018.
[RFC1034] Mockapetris, P., "Domain names - concepts and facilities", [RFC1034] Mockapetris, P., "Domain names - concepts and facilities",
STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987, STD 13, RFC 1034, DOI 10.17487/RFC1034, November 1987,
<https://www.rfc-editor.org/info/rfc1034>. <https://www.rfc-editor.org/info/rfc1034>.
 End of changes. 9 change blocks. 
11 lines changed or deleted 19 lines changed or added

This html diff was produced by rfcdiff 1.47. The latest version is available from http://tools.ietf.org/tools/rfcdiff/