draft-ietf-xrblock-rtcp-xr-burst-gap-loss-06.txt   draft-ietf-xrblock-rtcp-xr-burst-gap-loss-07.txt 
Audio/Video Transport Working Group A. Clark Audio/Video Transport Working Group A. Clark
Internet-Draft Telchemy Internet-Draft Telchemy
Intended status: Standards Track S. Zhang, Ed. Intended status: Standards Track S. Zhang, Ed.
Expires: June 8, 2013 J. Zhao Expires: June 24, 2013 J. Zhao
STTRI STTRI
Q. Wu Q. Wu
Huawei Huawei
December 5, 2012 December 21, 2012
RTP Control Protocol (RTCP) Extended Report (XR) Block for Burst/Gap RTP Control Protocol (RTCP) Extended Report (XR) Block for Burst/Gap
Loss metric Reporting Loss metric Reporting
draft-ietf-xrblock-rtcp-xr-burst-gap-loss-06.txt draft-ietf-xrblock-rtcp-xr-burst-gap-loss-07.txt
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 Loss metrics (XR) Block that allows the reporting of Burst and Gap Loss metrics
for use in a range of RTP applications. 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 37 skipping to change at page 1, line 37
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 June 8, 2013. This Internet-Draft will expire on June 24, 2013.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2012 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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1.1. Burst and Gap Loss Report Block . . . . . . . . . . . . . 3 1.1. Burst and Gap Loss Report Block . . . . . . . . . . . . . 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 . . . . . . . . . . . . . . . . . . . . . . 4 1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 5 2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 5
3. Burst/Gap Loss Block . . . . . . . . . . . . . . . . . . . . . 6 3. Burst/Gap Loss Block . . . . . . . . . . . . . . . . . . . . . 6
3.1. Report Block Structure . . . . . . . . . . . . . . . . . . 6 3.1. Report Block Structure . . . . . . . . . . . . . . . . . . 6
3.2. Definition of Fields in Burst/Gap Loss Report Block . . . 6 3.2. Definition of Fields in Burst/Gap Loss Report Block . . . 6
3.3. Derived metrics based on reported metrics . . . . . . . . 9 3.3. Derived metrics based on reported metrics . . . . . . . . 9
4. Considerations for Voice-over-IP applications . . . . . . . . 10 4. Considerations for Voice-over-IP applications . . . . . . . . 11
5. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 11 5. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 12
5.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 11 5.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 12
5.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 11 5.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 12
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
6.1. New RTCP XR Block Type value . . . . . . . . . . . . . . . 12 6.1. New RTCP XR Block Type value . . . . . . . . . . . . . . . 13
6.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 12 6.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 13
6.3. Contact information for registrations . . . . . . . . . . 12 6.3. Contact information for registrations . . . . . . . . . . 13
7. Security Considerations . . . . . . . . . . . . . . . . . . . 13 7. Security Considerations . . . . . . . . . . . . . . . . . . . 14
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 14 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 15
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
10.1. Normative References . . . . . . . . . . . . . . . . . . . 16 10.1. Normative References . . . . . . . . . . . . . . . . . . . 17
10.2. Informative References . . . . . . . . . . . . . . . . . . 16 10.2. Informative References . . . . . . . . . . . . . . . . . . 17
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 17 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 18
A.1. draft-ietf-xrblock-rtcp-xr-burst-gap-loss-06 . . . . . . . 17 A.1. draft-ietf-xrblock-rtcp-xr-burst-gap-loss-07 . . . . . . . 18
A.2. draft-ietf-xrblock-rtcp-xr-burst-gap-loss-04 . . . . . . . 17 A.2. draft-ietf-xrblock-rtcp-xr-burst-gap-loss-06 . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18 A.3. draft-ietf-xrblock-rtcp-xr-burst-gap-loss-04 . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction 1. Introduction
1.1. Burst and Gap Loss Report Block 1.1. Burst and Gap Loss Report Block
This draft defines a new block type to augment those defined in This draft defines a new block type to augment those defined in
[RFC3611] for use in a range of RTP applications. The new block type [RFC3611] for use in a range of RTP applications. The new block type
supports the reporting of the proportion of packets lost by the supports the reporting of the proportion of packets lost by the
network. The losses during loss bursts are reported, together with network. The losses during loss bursts are reported, together with
the number of bursts and additional data allowing the calculation of the number of bursts and additional data allowing the calculation of
statistical parameters (mean and variance) of the distribution of statistical parameters (mean and variance) of the distribution of
burst lengths. Some uses of these metrics depend on the availability burst lengths. Some uses of these metrics depend on the availability
of the metric "cumulative number of packets lost" from RTCP of the metric "cumulative number of packets lost" from RTCP
[RFC3550]. [RFC3550].
This block provides information on transient IP problems. Burst/Gap This block provides information on transient IP problems. Burst/Gap
metrics are typically used in Cumulative reports however MAY be used metrics are typically used in Cumulative reports, however they also
in Interval reports. The burstiness of packet loss affects user MAY be used in Interval reports. The burstiness of packet loss
experience, may influence any sender strategies to mitigate the affects user experience, may influence any sender strategies to
problem, and may also have diagnostic value. mitigate the problem, and may also have diagnostic value.
The metric belongs to the class of transport-related end system The metric belongs to the class of transport-related end system
metrics defined in [RFC6792]. metrics defined in [RFC6792].
The definitions of Burst, Gap, Loss and Discard are consistent with The definitions of Burst, Gap, Loss and Discard are consistent with
definitions in [RFC3611]. To accommodate the range of jitter buffer definitions in [RFC3611]. To accommodate the range of jitter buffer
algorithms and packet discard logic that may be used by implementors, algorithms and packet discard logic that may be used by implementors,
the method used to distinguish between bursts and gaps may be an the method used to distinguish between bursts and gaps may be an
equivalent method to that defined in [RFC3611]. The method used equivalent method to that defined in [RFC3611]. The method used
SHOULD produce the same result as that defined in [RFC3611] for SHOULD produce the same result as that defined in [RFC3611] for
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The Performance Metrics Framework [RFC6390] provides guidance on the The Performance Metrics Framework [RFC6390] provides guidance on the
definition and specification of performance metrics. The RTP definition and specification of performance metrics. The RTP
Monitoring Architectures [RFC6792] provides guideline for reporting Monitoring Architectures [RFC6792] provides guideline for reporting
block format using RTCP XR. The Metrics Block described in this block format using RTCP XR. The Metrics Block described in this
document are in accordance with the guidelines in [RFC6390] and document are in accordance with the guidelines in [RFC6390] and
[RFC6792]. [RFC6792].
1.4. Applicability 1.4. Applicability
These metrics are applicable to a range of RTP applications which These metrics are applicable to a range of RTP applications which
don't use stream repair means. contain jitter buffers and don't use stream repair means,e.g.,
Forward Error Correction (FEC) [RFC5109] and/or retransmission
[RFC4588].
2. Terminology 2. Terminology
2.1. Standards Language 2.1. Standards Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
In addition, the following terms are defined: In addition, the following terms are defined:
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enough to cause noticeable quality degradation (generally over 5 enough to cause noticeable quality degradation (generally over 5
percent loss rate), and gaps, which are periods during which lost percent loss rate), and gaps, which are periods during which lost
packets are infrequent and hence quality is generally acceptable. packets are infrequent and hence quality is generally acceptable.
3. Burst/Gap Loss Block 3. Burst/Gap Loss Block
Metrics in this block report on Burst/Gap Loss in the stream arriving Metrics in this block report on Burst/Gap Loss in the stream arriving
at the RTP system. The measurement of these metrics are made at the at the RTP system. The measurement of these metrics are made at the
receiving end of the RTP stream. Instances of this Metrics Block receiving end of the RTP stream. Instances of this Metrics Block
refer by Synchronization source (SSRC) to the separate auxiliary refer by Synchronization source (SSRC) to the separate auxiliary
Measurement Information block [RFC6776] which contains measurement Measurement Information block [RFC6776] which describes measurement
periods (see RFC6776 section 4.2). This metric block relies on the periods in use(see RFC6776 section 4.2). This Metrics Block relies
measurement period in the Measurement Information block indicating on the measurement period in the Measurement Information block
the span of the report and SHOULD be sent in the same compound RTCP indicating the span of the report and SHOULD be sent in the same
packet as the measurement information block. If the measurement compound RTCP packet as the measurement information block. If the
period is not received in the same compound RTCP packet as this measurement period is not received in the same compound RTCP packet
metric block, this metric block MUST be discarded. as this Metrics Block, this Metrics Block MUST be discarded.
3.1. Report Block Structure 3.1. Report Block Structure
Burst/Gap Loss metrics block Burst/Gap Loss metrics block
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BT=NBGL | I |C| resv. | block length = 5 | | BT=NBGL | I |C| resv. | block length = 5 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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I=10: Interval Duration - the reported value applies to the I=10: Interval Duration - the reported value applies to the
most recent measurement interval duration between successive most recent measurement interval duration between successive
metrics reports. metrics reports.
I=11: Cumulative Duration - the reported value applies to the I=11: Cumulative Duration - the reported value applies to the
accumulation period characteristic of cumulative measurements. accumulation period characteristic of cumulative measurements.
I=01: Sampled Value - the reported value is a sampled I=01: Sampled Value - the reported value is a sampled
instantaneous value. instantaneous value.
In this document, Burst/Gap Loss Metric is not measured at a In this document, Burst/Gap Loss Metrics can only be measured over
particular time instant but over one or several reporting definite intervals, and cannot be sampled. Accordingly, the value
intervals. Therefore Burst/Gap Loss Metric MUST NOT be chosen as I=01, indicating a sampled value, MUST NOT be used. In addition,
Sampled Metric. the value I=00 is reserved and also MUST NOT be used. The block
MUST be discarded if the value I=01 or I=00 is received.
Loss and Discard Combination flag (C): 1 bit Loss and Discard Combination flag (C): 1 bit
The 'C' flag is used to indicate whether combining loss/discard The 'C' flag is used to indicate whether combining loss/discard
report is needed. This field MUST be set to '1' if the burst gap report is needed. This field MUST be set to '1' if the burst gap
loss report is present in conjunction with the burst gap discard loss report is present in conjunction with the burst gap discard
report in the same compound RTCP packet and MUST be set to '0' report in the same compound RTCP packet and MUST be set to '0'
otherwise. If the burst gap discard is not sent with the burst otherwise. If the burst gap discard is not sent with the burst
gap loss, then the receiver MUST discard the burst gap loss with gap loss, then the receiver MUST discard the burst gap loss with
'C' flag set to 1. If the 'C' flag is set to 0, then receiver 'C' flag set to 1. If the 'C' flag is set to 0, then receiver
MUST NOT discard the burst gap loss metric block when the burst MUST NOT discard the burst gap loss Metrics Block when the burst
gap discard is not received. gap discard is not received.
Reserved (resv): 5 bits Reserved (resv): 5 bits
These bits are reserved. They SHOULD be set to zero by senders These bits are reserved. They MUST be set to zero by senders and
and MUST be ignored by receivers. ignored by receivers (See RFC6709 section 4.2). The block MUST be
discarded if the block length is set to a different value.
block length: 16 bits block length: 16 bits
The length of this report block in 32-bit words, minus one. For The length of this report block in 32-bit words, minus one. For
the Burst/Gap Loss block, the block length is equal to 5. the Burst/Gap Loss block, the block length is equal to 5. The
block MUST be discarded if the block length is set to a different
value.
SSRC of source: 32 bits SSRC of source: 32 bits
As defined in Section 4.1 of [RFC3611]. As defined in Section 4.1 of [RFC3611].
Threshold: 8 bits Threshold: 8 bits
The Threshold is equivalent to Gmin in [RFC3611], i.e. the number The Threshold is equivalent to Gmin in [RFC3611], i.e. the number
of successive packets that must be received prior to and following of successive packets that must be received prior to and following
a lost packet in order for this lost packet to be regarded as part a lost packet in order for this lost packet to be regarded as part
of a gap. of a gap.
Sum of Burst Durations (ms): 24 bits Sum of Burst Durations (ms): 24 bits
The total duration of bursts of lost packets in the period of the The total duration of bursts of lost packets in the period of the
report (Interval or Cumulative). report (Interval or Cumulative).
If the measured value exceeds 0xFFFFFD, the value 0xFFFFFE SHOULD If the measured value exceeds 0xFFFFFD, the value 0xFFFFFE MUST be
be reported to indicate an over-range measurement. If the reported to indicate an over-range measurement. If the
measurement is unavailable, the value 0xFFFFFF SHOULD be reported. measurement is unavailable, the value 0xFFFFFF MUST be reported.
Packets lost in bursts: 24 bits Packets lost in bursts: 24 bits
The total number of packets lost during loss bursts. The total number of packets lost during loss bursts.
If the measured value exceeds 0xFFFFFD, the value 0xFFFFFE SHOULD If the measured value exceeds 0xFFFFFD, the value 0xFFFFFE MUST be
be reported to indicate an over-range measurement. If the reported to indicate an over-range measurement. If the
measurement is unavailable, the value 0xFFFFFF SHOULD be reported. measurement is unavailable, the value 0xFFFFFF MUST be reported.
Total packets expected in bursts: 24 bits Total packets expected in bursts: 24 bits
The total number of packets expected during loss bursts (that is, The total number of packets expected during loss bursts (that is,
the sum of received packets and lost packets). the sum of received packets and lost packets).
If the measured value exceeds 0xFFFFFD, the value 0xFFFFFE SHOULD If the measured value exceeds 0xFFFFFD, the value 0xFFFFFE MUST be
be reported to indicate an over-range measurement. If the reported to indicate an over-range measurement. If the
measurement is unavailable, the value 0xFFFFFF SHOULD be reported. measurement is unavailable, the value 0xFFFFFF MUST be reported.
Number of bursts: 16 bits Number of bursts: 16 bits
The number of bursts in the period of the report (Interval or The number of bursts in the period of the report (Interval or
Cumulative). Cumulative).
If the measured value exceeds 0xFFFD, the value 0xFFFE SHOULD be If the measured value exceeds 0xFFFD, the value 0xFFFE MUST be
reported to indicate an over-range measurement. If the reported to indicate an over-range measurement. If the
measurement is unavailable, the value 0xFFFF SHOULD be reported. measurement is unavailable, the value 0xFFFF MUST be reported.
Sum of Squares of Burst Durations (ms-squared): 36 bits Sum of Squares of Burst Durations (ms-squared): 36 bits
The sum of the squares of burst durations (where individual burst The sum of the squares of burst durations (where individual burst
durations are expressed in ms) over in the period of the report durations are expressed in ms) over in the period of the report
(Interval or Cumulative). The units for this quantity are (Interval or Cumulative). The units for this quantity are
milliseconds-squared. milliseconds-squared.
If the measured value exceeds 0xFFFFFFFFD, the value 0xFFFFFFFFE If the measured value exceeds 0xFFFFFFFFD, the value 0xFFFFFFFFE
SHOULD be reported to indicate an over-range measurement. If the MUST be reported to indicate an over-range measurement. If the
measurement is unavailable, the value 0xFFFFFFFFF SHOULD be measurement is unavailable, the value 0xFFFFFFFFF MUST be
reported. reported.
3.3. Derived metrics based on reported metrics 3.3. Derived metrics based on reported metrics
The metrics described here are intended to be used as described in The metrics described here are intended to be used as described in
this section, in conjunction with information from the Measurement this section, in conjunction with information from the Measurement
Information block [RFC6776] (which MUST be present in the same RTCP Information block [RFC6776] (which MUST be present in the same RTCP
packet as the Burst/Gap Loss block) and also with the metric packet as the Burst/Gap Loss block) and also with the metric
"cumulative number of packets lost" provided in standard RTCP "cumulative number of packets lost" provided in standard RTCP
[RFC3550]. [RFC3550].
These metrics provides information relevant to statistical These metrics provide information relevant to statistical parameters,
parameters, including: including:
o The fraction of packets lost during bursts (i.e., Burst Loss Rate o The fraction of packets lost during bursts (i.e., Burst Loss Rate
in [SUMSTAT]) in [SUMSTAT]), which can be calculated using the metric " Packets
Loss in Bursts " and the metric " Total Packets expected in Bursts
" provided in the Burst/Gap Loss metrics block.
o The fraction of packets lost during gaps (i.e., Gap Loss Rate in o The fraction of packets lost during gaps (i.e., Gap Loss Rate in
[SUMSTAT]) [SUMSTAT]), which can be calculated using the metric " Packets
Loss in Bursts " and the metric " Total Packets expected in Bursts
" provided in the Burst/Gap Loss metrics block.
o burst duration mean [SUMSTAT] o burst duration mean [SUMSTAT], which can be calculated using the
metric " Packets Loss in Bursts " and the metric " Total Packets
expected in Bursts " provided in the Burst/Gap Loss metrics block.
o burst duration variance [SUMSTAT] o burst duration variance [SUMSTAT], which can be calculated using
the metric " Packets Loss in Bursts " and the metric " Total
Packets expected in Bursts " provided in the Burst/Gap Loss
metrics block.
The details on calculation these parameters in the metrics are The details on calculation these parameters in the metrics are
described in [SUMSTAT]. described in [SUMSTAT].
4. Considerations for Voice-over-IP applications 4. Considerations for Voice-over-IP applications
This metric block is applicable to a broad range of RTP applications. This Metrics Block is applicable to a broad range of RTP
Where the metric is used with a Voice-overIP (VoIP) application and applications. Where the metric is used with a Voice-overIP (VoIP)
the stream repair means is not available, the following application and the stream repair means is not available, the
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 loss rate is high enough to cause noticeable call during which the loss rate is high enough to cause noticeable call
quality degradation (generally over 5 percent loss rate), and gaps, quality degradation (generally over 5 percent loss rate), and gaps,
which are periods during which lost packets are infrequent and hence which are periods during which lost packets are infrequent and hence
call quality is generally acceptable. 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 shall
be determined as if silence packets had been sent, i.e. a period of be determined as if silence packets had been sent, i.e. a period of
silence in excess of Gmin packets MUST terminate a burst condition. silence in excess of Gmin packets MUST 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 PCM Severely Errored Second degraded to a similar extent to a typical Pulse-Code Modulation(PCM)
[PSES]. 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)
[RFC4566] for signaling the use of XR blocks. XR blocks MAY be used [RFC4566] for signaling the use of XR blocks. XR blocks MAY be used
without prior signaling. without prior signaling.
5.1. SDP rtcp-xr-attrib Attribute Extension 5.1. SDP rtcp-xr-attrib Attribute Extension
This section augments the SDP [RFC4566] attribute "rtcp-xr" defined This section augments the SDP [RFC4566] attribute "rtcp-xr" defined
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Geoff Hunt wrote the initial draft of this document. Geoff Hunt wrote the initial draft of this document.
9. Acknowledgments 9. Acknowledgments
The authors gratefully acknowledge reviews and feedback provided by The authors gratefully acknowledge reviews and feedback provided by
Bruce Adams, Philip Arden, Amit Arora, Bob Biskner, Kevin Connor, Bruce Adams, Philip Arden, Amit Arora, Bob Biskner, Kevin Connor,
Claus Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert Higashi, Claus Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert Higashi,
Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith Lantz, Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith Lantz,
Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, Ravi Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, Ravi
Raviraj, Albrecht Schwarz, Tom Taylor, Hideaki Yamada and Adam Roach. Raviraj, Albrecht Schwarz, Tom Taylor, Hideaki Yamada, Adam Roach and
Dan Romascanu..
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", March 1997. Requirement Levels", March 1997.
[RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time [RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time
Applications", RFC 3550, July 2003. Applications", RFC 3550, July 2003.
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[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)", November 2003. Protocol Extended Reports (RTCP XR)", November 2003.
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
Description Protocol", July 2006. Description Protocol", July 2006.
[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, February 2020. Reports (XRs)", RFC 5725, February 2020.
[RFC6709] Carpenter, B., Aboba, B., and S. Cheshire, "Design
Considerations for Protocol Extensions", RFC 6709,
September 2012.
10.2. Informative References 10.2. Informative References
[DISCARD] Wu, Q., "RTCP XR Report Block for Discard metric [DISCARD] Wu, Q., "RTCP XR Report Block for Discard metric
Reporting", ID draft-ietf-xrblock-rtcp-xr-discard-09, Reporting", ID draft-ietf-xrblock-rtcp-xr-discard-11,
October 2012. December 2012.
[PSES] "URL", http://www.its.bldrdoc.gov/projects/devglossary/ [RFC4588] Rey, J., Leon, D., , A., Varsa, V., and R. Hakenberg, "RTP
_severely_errored_second.html, October 2011. Retransmission Payload Format", RFC 4588, July 2006.
[RFC5109] Li, A., "RTP Payload Format for Generic Forward Error
Correction", RFC 5109, December 2007.
[RFC6390] Clark, A. and B. Claise, "Framework for Performance Metric [RFC6390] Clark, A. and B. Claise, "Framework for Performance Metric
Development", RFC 6390, July 2011. Development", RFC 6390, July 2011.
[RFC6776] Wu, Q., "Measurement Identity and information Reporting [RFC6776] Wu, Q., "Measurement Identity and information Reporting
using SDES item and XR Block", RFC 6776, October 2012. using SDES item and XR Block", RFC 6776, October 2012.
[RFC6792] Hunt, G., "Monitoring Architectures for RTP", RFC 6792, [RFC6792] Hunt, G., "Monitoring Architectures for RTP", RFC 6792,
November 2012. November 2012.
[SUMSTAT] Zorn, G., "RTCP XR for Summary Statistics Metrics [SUMSTAT] Zorn, G., "RTCP XR for Summary Statistics Metrics
Reporting", ID draft-ietf-xrblock-rtcp-xr-summary-stat-03, Reporting", ID draft-ietf-xrblock-rtcp-xr-summary-stat-05,
November 2012. December 2012.
Appendix A. Change Log Appendix A. 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.
A.1. draft-ietf-xrblock-rtcp-xr-burst-gap-loss-06 A.1. draft-ietf-xrblock-rtcp-xr-burst-gap-loss-07
The following are the major changes compared to previous version:
o Editorial changes based on comments in the WGLC.
A.2. draft-ietf-xrblock-rtcp-xr-burst-gap-loss-06
The following are the major changes compared to previous version: The following are the major changes compared to previous version:
o SDP update based on SDP Directorate Review. o SDP update based on SDP Directorate Review.
o Add some texts to get consistent with RFC6798 and Delay draft. o Add some texts to get consistent with RFC6798 and Delay draft.
A.2. draft-ietf-xrblock-rtcp-xr-burst-gap-loss-04 A.3. draft-ietf-xrblock-rtcp-xr-burst-gap-loss-04
The following are the major changes compared to previous version: The following are the major changes compared to previous version:
o Outdated reference update. o Outdated reference update.
o Editorial changes based on comments that applied to PDV and Delay o Editorial changes based on comments that applied to PDV and Delay
drafts. drafts.
Authors' Addresses Authors' Addresses
 End of changes. 32 change blocks. 
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