draft-ietf-xrblock-rtcp-xr-synchronization-08.txt   draft-ietf-xrblock-rtcp-xr-synchronization-09.txt 
Network Working Group H. Asaeda Network Working Group H. Asaeda
Internet-Draft NICT Internet-Draft NICT
Intended status: Standards Track Q. Wu Intended status: Standards Track Q. Wu
Expires: August 12, 2014 R. Huang Expires: August 30, 2014 R. Huang
Huawei Huawei
February 8, 2014 February 26, 2014
RTP Control Protocol (RTCP) Extended Report (XR) Blocks for RTP Control Protocol (RTCP) Extended Report (XR) Blocks for
Synchronization Delay and Offset Metrics Reporting Synchronization Delay and Offset Metrics Reporting
draft-ietf-xrblock-rtcp-xr-synchronization-08 draft-ietf-xrblock-rtcp-xr-synchronization-09
Abstract Abstract
This document defines two RTP Control Protocol (RTCP) Extended Report This document defines two RTP Control Protocol (RTCP) Extended Report
(XR) Blocks that allow the reporting of synchronization delay and (XR) Blocks that allow the reporting of synchronization delay and
offset metrics for use in a range of RTP applications. offset metrics for use in a range of RTP applications.
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 35 skipping to change at page 1, line 35
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 August 12, 2014. This Internet-Draft will expire on August 30, 2014.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 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
skipping to change at page 2, line 20 skipping to change at page 2, line 20
Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . . 3 1.2. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . . 3
1.3. Performance Metrics Framework . . . . . . . . . . . . . . 3 1.3. Performance Metrics Framework . . . . . . . . . . . . . . 3
1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 3 1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 4 2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 4
3. RTP Flows Initial Synchronization Delay Report Block . . . . . 5 3. RTP Flows Initial Synchronization Delay Report Block . . . . . 5
3.1. Metric Block Structure . . . . . . . . . . . . . . . . . . 5 3.1. Metric Block Structure . . . . . . . . . . . . . . . . . . 5
3.2. Definition of Fields in RTP Flow Initial 3.2. Definition of Fields in RTP Flow Initial
Synchronization Delay Metrics Block . . . . . . . . . . . 5 Synchronization Delay Metrics Block . . . . . . . . . . . 5
4. RTP Flows Synchronization Offset Metrics Block . . . . . . . . 6 4. RTP Flows Synchronization Offset Metrics Block . . . . . . . . 7
4.1. Metric Block Structure . . . . . . . . . . . . . . . . . . 7 4.1. Metric Block Structure . . . . . . . . . . . . . . . . . . 7
4.2. Definition of Fields in RTP Flow General 4.2. Definition of Fields in RTP Flow General
Synchronization Offset Metrics Block . . . . . . . . . . . 7 Synchronization Offset Metrics Block . . . . . . . . . . . 8
5. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 9 5. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 9
5.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 9 5.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 9
5.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 10 5.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 10
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 7. Security Considerations . . . . . . . . . . . . . . . . . . . 11
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 11
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
9.1. Normative References . . . . . . . . . . . . . . . . . . . 11 9.1. Normative References . . . . . . . . . . . . . . . . . . . 11
9.2. Informative References . . . . . . . . . . . . . . . . . . 11 9.2. Informative References . . . . . . . . . . . . . . . . . . 12
Appendix A. Metrics represented using RFC6390 Template . . . . . 12 Appendix A. Metrics represented using RFC6390 Template . . . . . 12
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 13 Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 13
B.1. draft-ietf-xrblock-rtcp-xr-syncronization-08 . . . . . . . 13 B.1. draft-ietf-xrblock-rtcp-xr-syncronization-09 . . . . . . . 14
B.2. draft-ietf-xrblock-rtcp-xr-syncronization-07 . . . . . . . 13 B.2. draft-ietf-xrblock-rtcp-xr-syncronization-08 . . . . . . . 14
B.3. draft-ietf-xrblock-rtcp-xr-syncronization-06 . . . . . . . 13 B.3. draft-ietf-xrblock-rtcp-xr-syncronization-07 . . . . . . . 14
B.4. draft-ietf-xrblock-rtcp-xr-syncronization-05 . . . . . . . 13 B.4. draft-ietf-xrblock-rtcp-xr-syncronization-06 . . . . . . . 14
B.5. draft-ietf-xrblock-rtcp-xr-syncronization-04 . . . . . . . 14 B.5. draft-ietf-xrblock-rtcp-xr-syncronization-05 . . . . . . . 14
B.6. draft-ietf-xrblock-rtcp-xr-syncronization-03 . . . . . . . 14 B.6. draft-ietf-xrblock-rtcp-xr-syncronization-04 . . . . . . . 14
B.7. draft-ietf-xrblock-rtcp-xr-syncronization-02 . . . . . . . 14 B.7. draft-ietf-xrblock-rtcp-xr-syncronization-03 . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14 B.8. draft-ietf-xrblock-rtcp-xr-syncronization-02 . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction 1. Introduction
1.1. Synchronization Delay and Offset Metrics Reporting Blocks 1.1. Synchronization Delay and Offset Metrics Reporting Blocks
This document defines two new block types to augment those defined in This document defines two new block types to augment those defined in
[RFC3611], for use in a range of RTP applications. [RFC3611], for use in a range of RTP applications.
The first new block type supports reporting of Initial The first new block type supports reporting of Initial
Synchronization Delay to establish multimedia session. Information Synchronization Delay to establish multimedia session. Information
is recorded about time difference between the start of RTP sessions is recorded about time difference between the start of RTP sessions
and the time the RTP receiver acquires all components of RTP sessions and the time the RTP receiver acquires all components of RTP sessions
in the multimedia session [RFC6051]. in the multimedia session [RFC6051].
The second new block type supports reporting of the relative The second new block type supports reporting of the relative
synchronization offset time of two arbitrary streams (e.g., between synchronization offset time of two arbitrary streams (e.g., between
audio and video streams), with the same RTCP CNAME included in RTCP audio and video streams), with the same RTCP CNAME included in RTCP
SDES packets [RFC3550]. Source description items (SDES) packets [RFC3550].
These metrics belong to the class of transport level metrics defined These metrics belong to the class of transport level metrics defined
in [RFC6792]. in [RFC6792].
1.2. RTCP and RTCP XR Reports 1.2. RTCP and RTCP XR Reports
The use of RTCP for reporting is defined in [RFC3550]. [RFC3611] The use of RTCP for reporting is defined in [RFC3550]. [RFC3611]
defined an extensible structure for reporting using an RTCP Extended defined an extensible structure for reporting using an RTCP Extended
Report (XR). This document defines a new Extended Report block for Report (XR). This document defines a new Extended Report block for
use with [RFC3550] and [RFC3611]. use with [RFC3550] and [RFC3611].
skipping to change at page 3, line 44 skipping to change at page 3, line 44
The RTP Monitoring Architectures [RFC6792] provides guideline for The RTP Monitoring Architectures [RFC6792] provides guideline for
reporting block format using RTCP XR. The new report block described reporting block format using RTCP XR. The new report block described
in this memo is in compliance with the monitoring architecture in this memo is in compliance with the monitoring architecture
specified in [RFC6792]. specified in [RFC6792].
1.4. Applicability 1.4. Applicability
When joining each session in layered video sessions [RFC6190] or the When joining each session in layered video sessions [RFC6190] or the
multimedia session, a receiver may not synchronize playout across the multimedia session, a receiver may not synchronize playout across the
multimedia session or layered video session until RTCP SR packets multimedia session or layered video session until RTCP Sender Report
have been received on all components of RTP sessions. The component (SR) packets have been received on all components of RTP sessions.
RTP session are referred to as each RTP session for each media type The component RTP session are referred to as each RTP session for
in multimedia session or separate RTP session for each layer in the each media type in multimedia session or separate RTP session for
layered video session. For multicast session, the initial each layer in the layered video session. For multicast session, the
synchronization delay metric varies with the session bandwidth, the initial synchronization delay metric varies with the session
number of members, and the number of senders in the session. The RTP bandwidth, the number of members, and the number of senders in the
flow Initial synchronization delay block defined in this document can session. The RTP flow Initial synchronization delay block defined in
be used to report such metric, i.e., the initial synchronization this document can be used to report such metric, i.e., the initial
delay to receive all the RTP streams belonging to the same multimedia synchronization delay to receive all the RTP streams belonging to the
session or layered video session. In the absence of packet loss, the same multimedia session or layered video session. In the absence of
initial synchronization delay equals to the average time taken to packet loss, the initial synchronization delay equals to the average
receive the first RTCP packet in the RTP session with the longest time taken to receive the first RTCP packet in the RTP session with
RTCP reporting interval. In the presence of packet loss, the media the longest RTCP reporting interval. In the presence of packet loss,
synchronization should rely on the in-band mapping of RTP and NTP- the media synchronization should rely on the in-band mapping of RTP
format timestamps [RFC6051] or wait until the reporting interval has and NTP-format timestamps [RFC6051] or wait until the reporting
passed, and the next RTCP SR packet is sent. interval has passed, and the next RTCP SR packet is sent.
Receivers of the RTP flow initial synchronization delay block could Receivers of the RTP flow initial synchronization delay block could
use this metric to compare with targets (i.e., Service Level use this metric to compare with targets (i.e., Service Level
Agreement or thresholds of the system) to help ensure the quality of Agreement or thresholds of the system) to help ensure the quality of
real-time application performance. real-time application performance.
In an RTP multimedia session, there can be an arbitrary number of In an RTP multimedia session, there can be an arbitrary number of
streams carried in different RTP sessions, with the same RTCP CNAME. streams carried in different RTP sessions, with the same RTCP CNAME.
These streams may be not synchronized with each other. For example, These streams may be not synchronized with each other. For example,
one audio stream and one video stream belong to the same session, and one audio stream and one video stream belong to the same session, and
skipping to change at page 5, line 8 skipping to change at page 5, line 8
A multimedia session comprises a set of concurrent RTP sessions A multimedia session comprises a set of concurrent RTP sessions
among a common group of participants, using one RTP session for among a common group of participants, using one RTP session for
each media type. The initial synchronization Delay is the average each media type. The initial synchronization Delay is the average
time for receiver to synchronize all components of a multimedia time for receiver to synchronize all components of a multimedia
session [RFC6051]. session [RFC6051].
Synchronization Offset: Synchronization Offset:
Synchronization between two media streams must be maintained to Synchronization between two media streams must be maintained to
ensure satisfactory QoE. Two media streams can be of the same or ensure satisfactory Quality of Experience (QoE). Two media
different media type belonging to one RTP session or in different streams can be of the same or different media type belonging to
media types belonging to one multimedia session. The one RTP session or in different media types belonging to one
Synchronization Offset is the relative time difference of the two multimedia session. The Synchronization Offset is the relative
media streams that need to be synchronized. time difference of the two media streams that need to be
synchronized.
3. RTP Flows Initial Synchronization Delay Report Block 3. RTP Flows Initial Synchronization Delay Report Block
This block is sent by RTP receivers and reports Initial This block is sent by RTP receivers and reports Initial
synchronization delay beyond the information carried in the standard synchronization delay beyond the information carried in the standard
RTCP packet format. Information is recorded about time difference RTCP packet format. Information is recorded about time difference
between the start of multimedia session and the time when the RTP between the start of multimedia session and the time when the RTP
receiver acquires all components of RTP sessions [RFC6051] measured receiver acquires all components of RTP sessions [RFC6051] measured
at the receiving end of RTP stream. at the receiving end of RTP stream.
skipping to change at page 10, line 38 skipping to change at page 10, line 46
Reference: Section 4 Reference: Section 4
This document also registers two new SDP [RFC4566] parameters for the This document also registers two new SDP [RFC4566] parameters for the
"rtcp-xr" attribute in the RTCP XR SDP Parameters Registry: "rtcp-xr" attribute in the RTCP XR SDP Parameters Registry:
* "rtp-flow-init-syn-delay " * "rtp-flow-init-syn-delay "
* "rtp-flow-syn-offset" * "rtp-flow-syn-offset"
The contact information for the registrations is: The contact information for the registrations is:
Qin Wu RAI Area Directors
sunseawq@huawei.com <rai-ads@tools.ietf.org>
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012, China
7. Security Considerations 7. Security Considerations
The new RTCP XR report blocks proposed in this document introduces no When using Secure RTP [RFC3711], or other media layer security,
reporting accurate synchronisation offset information can expose some
details about the timing of the cryptographic operations that are
used to protect the media. There is a possibility that this timing
information might enable a side-channel attack on the encryption.
For environments where this attack is a concern, implementations need
to take care to ensure cryptographic processing and media compression
take the same amount of time irrespective of the media content, to
avoid the potential attack.
Besides this, it is believed that this RTCP XR block introduces no
new security considerations beyond those described in [RFC3611]. new security considerations beyond those described in [RFC3611].
8. Acknowledgements 8. Acknowledgements
The authors would like to thank Bill Ver Steeg, David R Oran, Ali The authors would like to thank Bill Ver Steeg, David R Oran, Ali
Begen, Colin Perkins, Roni Even, Kevin Gross, Jing Zhao, Fernando Begen, Colin Perkins, Roni Even, Kevin Gross, Jing Zhao, Fernando
Boronat Segui, Mario Montagud Climent, Youqing Yang, Wenxiao Yu and Boronat Segui, Mario Montagud Climent, Youqing Yang, Wenxiao Yu and
Yinliang Hu,Jonathan Lennox for their valuable comments and Yinliang Hu,Jonathan Lennox, Stephen Farrel for their valuable
suggestions on this document. comments and suggestions on this document.
9. References 9. References
9.1. Normative References 9.1. Normative References
[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.
[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V.
Jacobson, "RTP: A Transport Protocol for Real-Time Jacobson, "RTP: A Transport Protocol for Real-Time
Applications", STD 64, RFC 3550, July 2003. Applications", STD 64, RFC 3550, July 2003.
[RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control
Protocol Extended Reports (RTCP XR)", RFC 3611, Protocol Extended Reports (RTCP XR)", RFC 3611,
November 2003. November 2003.
[RFC3711] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K.
Norrman, "The Secure Real-time Transport Protocol (SRTP)",
RFC 3711, March 2004.
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
Description Protocol", RFC 4566, July 2006. Description Protocol", RFC 4566, July 2006.
[RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008. Specifications: ABNF", STD 68, RFC 5234, January 2008.
[RFC5905] Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network [RFC5905] Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network
Time Protocol Version 4: Protocol and Algorithms Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, June 2010. Specification", RFC 5905, June 2010.
skipping to change at page 13, line 24 skipping to change at page 14, line 5
* Use and applications: See section 1.4 [RFCXXXX]. * Use and applications: See section 1.4 [RFCXXXX].
* Reporting model: See RFC3611. * Reporting model: See RFC3611.
Appendix B. Change Log Appendix B. Change Log
Note to the RFC-Editor: please remove this section prior to Note to the RFC-Editor: please remove this section prior to
publication as an RFC. publication as an RFC.
B.1. draft-ietf-xrblock-rtcp-xr-syncronization-08 B.1. draft-ietf-xrblock-rtcp-xr-syncronization-09
The following are the major changes compared to previous version:
Some Editorial changes based on IESG Review comments.
B.2. draft-ietf-xrblock-rtcp-xr-syncronization-08
The following are the major changes compared to previous version: The following are the major changes compared to previous version:
Some Editorial changes based on Gen-Art Reviewer comments. Some Editorial changes based on Gen-Art Reviewer comments.
B.2. draft-ietf-xrblock-rtcp-xr-syncronization-07 B.3. draft-ietf-xrblock-rtcp-xr-syncronization-07
The following are the major changes compared to previous version: The following are the major changes compared to previous version:
Minor Editorial changes. Minor Editorial changes.
B.3. draft-ietf-xrblock-rtcp-xr-syncronization-06 B.4. draft-ietf-xrblock-rtcp-xr-syncronization-06
The following are the major changes compared to previous version: The following are the major changes compared to previous version:
Some Editorial changes. Some Editorial changes.
B.4. draft-ietf-xrblock-rtcp-xr-syncronization-05 B.5. draft-ietf-xrblock-rtcp-xr-syncronization-05
The following are the major changes compared to previous version: The following are the major changes compared to previous version:
Editorial changes and typo fixed. Editorial changes and typo fixed.
B.5. draft-ietf-xrblock-rtcp-xr-syncronization-04 B.6. draft-ietf-xrblock-rtcp-xr-syncronization-04
The following are the major changes compared to previous version: The following are the major changes compared to previous version:
Additional text to clarify on how to distinguish report stream Additional text to clarify on how to distinguish report stream
from reference stream. from reference stream.
Other Editorial changes. Other Editorial changes.
B.6. draft-ietf-xrblock-rtcp-xr-syncronization-03 B.7. draft-ietf-xrblock-rtcp-xr-syncronization-03
The following are the major changes compared to previous version: The following are the major changes compared to previous version:
Remove the need to signal the reference source in the Remove the need to signal the reference source in the
synchronisation offset metrics RTCP XR report. synchronisation offset metrics RTCP XR report.
Apply RFC6390 template to metrics in the appendix. Apply RFC6390 template to metrics in the appendix.
Other editorial changes to get inline with other XRBLOCK drafts. Other editorial changes to get inline with other XRBLOCK drafts.
B.7. draft-ietf-xrblock-rtcp-xr-syncronization-02 B.8. draft-ietf-xrblock-rtcp-xr-syncronization-02
The following are the major changes compared to previous version: The following are the major changes compared to previous version:
Editorial change based on comments raised on the list and in the Editorial change based on comments raised on the list and in the
IETF85 meeting IETF85 meeting
Authors' Addresses Authors' Addresses
Hitoshi Asaeda Hitoshi Asaeda
National Institute of Information and Communications Technology National Institute of Information and Communications Technology
 End of changes. 23 change blocks. 
53 lines changed or deleted 73 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/