draft-ietf-xrblock-independent-burst-gap-discard-01.txt   draft-ietf-xrblock-independent-burst-gap-discard-02.txt 
Audio/Video Transport Working Group V. Singh Audio/Video Transport Working Group V. Singh
Internet-Draft callstats.io Internet-Draft callstats.io
Intended status: Standards Track C. Perkins Intended status: Standards Track C. Perkins
Expires: September 22, 2016 University of Glasgow Expires: December 29, 2016 University of Glasgow
A. Clark A. Clark
Telchemy Telchemy
R. Huang R. Huang
Huawei Huawei
March 21, 2016 June 27, 2016
RTP Control Protocol (RTCP) Extended Report (XR) Block for Independent RTP Control Protocol (RTCP) Extended Report (XR) Block for Independent
Reporting of Burst/Gap Discard Metric Reporting of Burst/Gap Discard Metric
draft-ietf-xrblock-independent-burst-gap-discard-01 draft-ietf-xrblock-independent-burst-gap-discard-02
Abstract Abstract
This document defines an RTP Control Protocol (RTCP) Extended Report This document defines an RTP Control Protocol (RTCP) Extended Report
(XR) block that allows the reporting of burst and gap discard metrics (XR) block that allows the reporting of burst and gap discard metrics
independently of the burst and gap loss metrics for use in a range of independently of the burst and gap loss metrics for use in a range of
RTP applications. RTP applications.
Status of This Memo Status of This Memo
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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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 September 22, 2016. This Internet-Draft will expire on December 29, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 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
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6.1. New RTCP XR Block Type Value . . . . . . . . . . . . . . 9 6.1. New RTCP XR Block Type Value . . . . . . . . . . . . . . 9
6.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 9 6.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 9
6.3. Contact Information for Registrations . . . . . . . . . . 9 6.3. Contact Information for Registrations . . . . . . . . . . 9
7. Security Considerations . . . . . . . . . . . . . . . . . . . 9 7. Security Considerations . . . . . . . . . . . . . . . . . . . 9
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
10.1. Normative References . . . . . . . . . . . . . . . . . . 10 10.1. Normative References . . . . . . . . . . . . . . . . . . 10
10.2. Informative References . . . . . . . . . . . . . . . . . 11 10.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. Metrics Represented Using the Template from RFC 6390 13 Appendix A. Metrics Represented Using the Template from RFC 6390 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction 1. Introduction
1.1. Burst-Gap Discard Metrics Block 1.1. Burst-Gap Discard Metrics Block
This document defines a new block type that extends the metrics This document defines a new block type that extends the metrics
defined in [RFC7003]. The new block type reports the proportion of defined in [RFC7003]. The new block type reports the proportion of
packets discarded in a burst by the dejitter buffer at the receiver. packets discarded in a burst by the dejitter buffer at the receiver.
The number of packets discarded depends on the dejitter buffer The number of packets discarded depends on the dejitter buffer
algorithm implemented by the endpoint. algorithm implemented by the endpoint.
The new report block defined in this document is different from the The new report block defined in this document is different from the
one defined in [RFC7003]. The metrics in [RFC7003] depends on the one defined in [RFC7003]. The metrics in [RFC7003] depends on the
metrics in the burst-gap loss metric defined in [RFC6958]. metrics in the burst-gap loss metric defined in [RFC6958].
Consequently, an endpoint using [RFC7003] MUST report it along with
Consequently, an endpoint using [RFC7003] MUST report it along with
[RFC6958] for it to be useful. The combined usage is useful when an [RFC6958] for it to be useful. The combined usage is useful when an
endpoint observes correlated packet losses and discard. However, endpoint observes correlated packet losses and discard. However,
when the burst of packet losses and discards do not occur when the burst of packet losses and discards do not occur
simultaneously, the application may prefer a concise report block simultaneously, the application may prefer a concise report block
that just reports the burst-gap of discarded packets. The report that just reports the burst-gap of discarded packets. The report
block in this document provides the complete information and does not block in this document provides the complete information and does not
require additional report blocks. That is, this block reports: the require additional report blocks. That is, this block reports: the
total number of packets discarded, the total burst duration, and the total number of packets discarded, the total burst duration, and the
total number of bursts, all of these metrics are missing in total number of bursts, all of these metrics are missing in
[RFC7003]. [RFC7003].
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burst affects the user experience. Based on the metrics reported in burst affects the user experience. Based on the metrics reported in
the block, the sending endpoint may change the packetization the block, the sending endpoint may change the packetization
interval, vary the bitrate, etc. The report may additionally be used interval, vary the bitrate, etc. The report may additionally be used
for diagnostics [RFC6792]. The metric belongs to the class of for diagnostics [RFC6792]. The metric belongs to the class of
transport-related end-system metrics defined in [RFC6792]. transport-related end-system metrics defined in [RFC6792].
The definitions of "burst", "gap", "loss", and "discard" are The definitions of "burst", "gap", "loss", and "discard" are
consistent with the definitions in [RFC3611]. To accommodate a range consistent with the definitions in [RFC3611]. To accommodate a range
of dejitter buffer algorithms and packet discard logic that may be of dejitter buffer algorithms and packet discard logic that may be
used by implementors, the method used to distinguish between bursts used by implementors, the method used to distinguish between bursts
and gaps shall use an equivalent method to that defined in and gaps use an equivalent method to that defined in Section 4.7.2 of
Section 4.7.2 of [RFC3611]. Note that reporting the specific [RFC3611]. Note that reporting the specific dejitter buffer
dejitter buffer algorithm and/or the packet discard logic is out of algorithm and/or the packet discard logic is out of the scope of this
the scope of this document. document.
1.2. RTCP and RTCP Extended Reports 1.2. RTCP and RTCP Extended 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].
1.3. Performance Metrics Framework 1.3. Performance Metrics Framework
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applications. Where the metric is used with a Voice-over-IP (VoIP) applications. Where the metric is used with a Voice-over-IP (VoIP)
application and the stream repair means is not available, the application and the stream repair means is not available, the
following considerations apply. following considerations apply.
RTCP XR views a call as being divided into bursts, which are periods RTCP XR views a call as being divided into bursts, which are periods
during which the discard rate is high enough to cause noticeable call during which the discard rate is high enough to cause noticeable call
quality degradation (generally over 5 percent discard rate) and gaps, quality degradation (generally over 5 percent discard rate) and gaps,
which are periods during which discarded packets are infrequent and which are periods during which discarded packets are infrequent and
hence call quality is generally acceptable. hence call quality is generally acceptable.
If voice activity detection is used, the burst and gap duration shall If voice activity detection is used, the burst and gap duration is
be determined as if silence packets had been sent, i.e., a period of determined as if silence packets had been sent, i.e., a period of
silence in excess of Gmin packets will terminate a burst condition. silence in excess of Gmin packets will terminate a burst condition.
The recommended value for the threshold Gmin in [RFC3611] results in The recommended value for the threshold Gmin in [RFC3611] results in
a burst being a period of time during which the call quality is a burst being a period of time during which the call quality is
degraded to a similar extent to a typical pulse code modulation (PCM) degraded to a similar extent to a typical pulse code modulation (PCM)
severely errored second. severely errored second.
5. SDP Signaling 5. SDP Signaling
[RFC3611] defines the use of SDP (Session Description Protocol) [RFC3611] defines the use of SDP (Session Description Protocol)
skipping to change at page 9, line 41 skipping to change at page 9, line 41
6.2. New RTCP XR SDP Parameter 6.2. New RTCP XR SDP Parameter
This document also registers a new parameter "ind-burst-gap-discard" This document also registers a new parameter "ind-burst-gap-discard"
in the "RTP Control Protocol Extended Reports (RTCP XR) Session in the "RTP Control Protocol Extended Reports (RTCP XR) Session
Description Protocol (SDP) Parameters Registry". Description Protocol (SDP) Parameters Registry".
6.3. Contact Information for Registrations 6.3. Contact Information for Registrations
The contact information for the registrations is: The contact information for the registrations is:
ART Area Directors <art-ads@tools.ietf.org> ART Area Directors <art-ads@ietf.org>
7. Security Considerations 7. Security Considerations
It is believed that this RTCP XR block introduces no new security This block does not provide per-packet statistics, so the risk to
considerations beyond those described in [RFC3611]. This block does confidentiality documented in Section 7, paragraph 3 of [RFC3611]
not provide per-packet statistics, so the risk to confidentiality does not apply. However the gap indicated within this block could be
documented in Section 7, paragraph 3 of [RFC3611] does not apply. used to detect the timing of other events on the path between the
sender and receiver. For example, a competing multimedia stream
might cause a discard burst for the duration of the stream, allowing
the receiver of this block to know when the competing stream was
active. This risk is not a significant threat since the only
information leaked is the timing of the discard, not the cause.
Where this is a concern, the implementation should apply encryption
and authentication to this report block. For example, this can be
achieved by using the Audio-Visual Profile with Feedback (AVPF)
profile together with the Secure RTP profile, as defined in
[RFC3711]; an appropriate combination of those two profiles ("SAVPF")
is specified in [RFC5124]. Besides this, it is believed that this
RTCP XR block introduces no new security considerations beyond those
described in [RFC3611].
8. Contributors 8. Contributors
Qin Wu, Rachel Huang, and Alan Clark wrote RFC7003, which this Qin Wu, Rachel Huang, and Alan Clark wrote RFC7003, which this
document extends. document extends.
9. Acknowledgments 9. Acknowledgments
The authors would like to thank Paul Kyzivat, Jan Novak, Dan The authors would like to thank Paul Kyzivat, Jan Novak, Dan
Romascanu for providing valuable feedback on earlier versions of this Romascanu for providing valuable feedback on earlier versions of this
draft. draft.
10. References 10. References
10.1. Normative References 10.1. 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, DOI 10.17487/ Requirement Levels", BCP 14, RFC 2119,
RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[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, DOI 10.17487/RFC3550, Applications", STD 64, RFC 3550, DOI 10.17487/RFC3550,
July 2003, <http://www.rfc-editor.org/info/rfc3550>. July 2003, <http://www.rfc-editor.org/info/rfc3550>.
[RFC3611] Friedman, T., Ed., Caceres, R., Ed., and A. Clark, Ed., [RFC3611] Friedman, T., Ed., Caceres, R., Ed., and A. Clark, Ed.,
"RTP Control Protocol Extended Reports (RTCP XR)", RFC "RTP Control Protocol Extended Reports (RTCP XR)",
3611, DOI 10.17487/RFC3611, November 2003, RFC 3611, DOI 10.17487/RFC3611, November 2003,
<http://www.rfc-editor.org/info/rfc3611>. <http://www.rfc-editor.org/info/rfc3611>.
[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,
<http://www.rfc-editor.org/info/rfc3711>.
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
Description Protocol", RFC 4566, DOI 10.17487/RFC4566, Description Protocol", RFC 4566, DOI 10.17487/RFC4566,
July 2006, <http://www.rfc-editor.org/info/rfc4566>. July 2006, <http://www.rfc-editor.org/info/rfc4566>.
[RFC5124] Ott, J. and E. Carrara, "Extended Secure RTP Profile for
Real-time Transport Control Protocol (RTCP)-Based Feedback
(RTP/SAVPF)", RFC 5124, DOI 10.17487/RFC5124, February
2008, <http://www.rfc-editor.org/info/rfc5124>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, DOI 10.17487/ Specifications: ABNF", STD 68, RFC 5234,
RFC5234, January 2008, DOI 10.17487/RFC5234, January 2008,
<http://www.rfc-editor.org/info/rfc5234>. <http://www.rfc-editor.org/info/rfc5234>.
[RFC5725] Begen, A., Hsu, D., and M. Lague, "Post-Repair Loss RLE [RFC5725] Begen, A., Hsu, D., and M. Lague, "Post-Repair Loss RLE
Report Block Type for RTP Control Protocol (RTCP) Extended Report Block Type for RTP Control Protocol (RTCP) Extended
Reports (XRs)", RFC 5725, DOI 10.17487/RFC5725, February Reports (XRs)", RFC 5725, DOI 10.17487/RFC5725, February
2010, <http://www.rfc-editor.org/info/rfc5725>. 2010, <http://www.rfc-editor.org/info/rfc5725>.
[RFC6776] Clark, A. and Q. Wu, "Measurement Identity and Information [RFC6776] Clark, A. and Q. Wu, "Measurement Identity and Information
Reporting Using a Source Description (SDES) Item and an Reporting Using a Source Description (SDES) Item and an
RTCP Extended Report (XR) Block", RFC 6776, DOI 10.17487/ RTCP Extended Report (XR) Block", RFC 6776,
RFC6776, October 2012, DOI 10.17487/RFC6776, October 2012,
<http://www.rfc-editor.org/info/rfc6776>. <http://www.rfc-editor.org/info/rfc6776>.
[RFC7003] Clark, A., Huang, R., and Q. Wu, Ed., "RTP Control [RFC7003] Clark, A., Huang, R., and Q. Wu, Ed., "RTP Control
Protocol (RTCP) Extended Report (XR) Block for Burst/Gap Protocol (RTCP) Extended Report (XR) Block for Burst/Gap
Discard Metric Reporting", RFC 7003, DOI 10.17487/RFC7003, Discard Metric Reporting", RFC 7003, DOI 10.17487/RFC7003,
September 2013, <http://www.rfc-editor.org/info/rfc7003>. September 2013, <http://www.rfc-editor.org/info/rfc7003>.
10.2. Informative References 10.2. Informative References
[I-D.ietf-payload-flexible-fec-scheme] [I-D.ietf-payload-flexible-fec-scheme]
Singh, V., Begen, A., Zanaty, M., and G. Mandyam, "RTP Singh, V., Begen, A., Zanaty, M., and G. Mandyam, "RTP
Payload Format for Flexible Forward Error Correction Payload Format for Flexible Forward Error Correction
(FEC)", draft-ietf-payload-flexible-fec-scheme-01 (work in (FEC)", draft-ietf-payload-flexible-fec-scheme-02 (work in
progress), October 2015. progress), March 2016.
[RFC4588] Rey, J., Leon, D., Miyazaki, A., Varsa, V., and R. [RFC4588] Rey, J., Leon, D., Miyazaki, A., Varsa, V., and R.
Hakenberg, "RTP Retransmission Payload Format", RFC 4588, Hakenberg, "RTP Retransmission Payload Format", RFC 4588,
DOI 10.17487/RFC4588, July 2006, DOI 10.17487/RFC4588, July 2006,
<http://www.rfc-editor.org/info/rfc4588>. <http://www.rfc-editor.org/info/rfc4588>.
[RFC5481] Morton, A. and B. Claise, "Packet Delay Variation [RFC5481] Morton, A. and B. Claise, "Packet Delay Variation
Applicability Statement", RFC 5481, DOI 10.17487/RFC5481, Applicability Statement", RFC 5481, DOI 10.17487/RFC5481,
March 2009, <http://www.rfc-editor.org/info/rfc5481>. March 2009, <http://www.rfc-editor.org/info/rfc5481>.
[RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New [RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New
Performance Metric Development", BCP 170, RFC 6390, DOI Performance Metric Development", BCP 170, RFC 6390,
10.17487/RFC6390, October 2011, DOI 10.17487/RFC6390, October 2011,
<http://www.rfc-editor.org/info/rfc6390>. <http://www.rfc-editor.org/info/rfc6390>.
[RFC6709] Carpenter, B., Aboba, B., Ed., and S. Cheshire, "Design [RFC6709] Carpenter, B., Aboba, B., Ed., and S. Cheshire, "Design
Considerations for Protocol Extensions", RFC 6709, DOI Considerations for Protocol Extensions", RFC 6709,
10.17487/RFC6709, September 2012, DOI 10.17487/RFC6709, September 2012,
<http://www.rfc-editor.org/info/rfc6709>. <http://www.rfc-editor.org/info/rfc6709>.
[RFC6792] Wu, Q., Ed., Hunt, G., and P. Arden, "Guidelines for Use [RFC6792] Wu, Q., Ed., Hunt, G., and P. Arden, "Guidelines for Use
of the RTP Monitoring Framework", RFC 6792, DOI 10.17487/ of the RTP Monitoring Framework", RFC 6792,
RFC6792, November 2012, DOI 10.17487/RFC6792, November 2012,
<http://www.rfc-editor.org/info/rfc6792>. <http://www.rfc-editor.org/info/rfc6792>.
[RFC6958] Clark, A., Zhang, S., Zhao, J., and Q. Wu, Ed., "RTP [RFC6958] Clark, A., Zhang, S., Zhao, J., and Q. Wu, Ed., "RTP
Control Protocol (RTCP) Extended Report (XR) Block for Control Protocol (RTCP) Extended Report (XR) Block for
Burst/Gap Loss Metric Reporting", RFC 6958, DOI 10.17487/ Burst/Gap Loss Metric Reporting", RFC 6958,
RFC6958, May 2013, DOI 10.17487/RFC6958, May 2013,
<http://www.rfc-editor.org/info/rfc6958>. <http://www.rfc-editor.org/info/rfc6958>.
[RFC7002] Clark, A., Zorn, G., and Q. Wu, "RTP Control Protocol [RFC7002] Clark, A., Zorn, G., and Q. Wu, "RTP Control Protocol
(RTCP) Extended Report (XR) Block for Discard Count Metric (RTCP) Extended Report (XR) Block for Discard Count Metric
Reporting", RFC 7002, DOI 10.17487/RFC7002, September Reporting", RFC 7002, DOI 10.17487/RFC7002, September
2013, <http://www.rfc-editor.org/info/rfc7002>. 2013, <http://www.rfc-editor.org/info/rfc7002>.
Appendix A. Metrics Represented Using the Template from RFC 6390 Appendix A. Metrics Represented Using the Template from RFC 6390
a. Threshold Metric a. Threshold Metric
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