Internet DRAFT - draft-zorn-xrblock-rtcp-xr-al-stat
draft-zorn-xrblock-rtcp-xr-al-stat
Network Working Group G. Zorn
Internet-Draft Network Zen
Intended status: Standards Track R. Schott
Expires: January 11, 2013 Deutsche Telekom
Q. Wu
R. Huang
Huawei
July 10, 2012
RTCP XR for Summary Statistics Metrics Reporting
draft-zorn-xrblock-rtcp-xr-al-stat-06
Abstract
This document defines three RTCP XR Report Blocks and associated SDP
parameters that allows the reporting of loss, duplication and discard
summary statistics metrics for use in a range of RTP applications.
Status of this Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 3
3. Transport Layer Metrics . . . . . . . . . . . . . . . . . . . 4
3.1. Burst/Gap Loss Summary Statistics Block . . . . . . . . . 4
3.1.1. Report Block Structure . . . . . . . . . . . . . . . . 4
3.1.2. Definition of Fields in Loss Summary Statistics
Block . . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. Burst/Gap Discard Summary Statistics Block . . . . . . . . 6
3.2.1. Report Block Structure . . . . . . . . . . . . . . . . 6
3.2.2. Definition of Fields in Discard Summary Statistics
Block . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Application Layer Metrics . . . . . . . . . . . . . . . . . . 8
4.1. Frame Impairment Statistics Summary Block . . . . . . . . 8
4.1.1. Report Block Structure . . . . . . . . . . . . . . . . 9
4.1.2. Definition of Fields in Frame Impairment Summary
Statistics Block . . . . . . . . . . . . . . . . . . . 9
5. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 11
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
6.1. New RTCP XR Block Type values . . . . . . . . . . . . . . 11
6.2. New RTCP XR SDP Parameters . . . . . . . . . . . . . . . . 12
6.3. Contact information for registrations . . . . . . . . . . 12
7. Security Considerations . . . . . . . . . . . . . . . . . . . 12
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
9.1. Normative References . . . . . . . . . . . . . . . . . . . 12
9.2. Informative References . . . . . . . . . . . . . . . . . . 13
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
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1. Introduction
This draft defines three new block types to augment those defined in
[RFC3611] for use in a range of RTP applications.
The first two block types support the reporting of burst gap loss/
discard, summary statistics including packet loss/discard proportion,
mean and variance and belong to the class of transport layer metrics
defined in [MONARCH]. These two blocks are intended to be used in
conjunction with information from the Burst Gap Loss metric block or
burst gap discard metric block, and on which these two block
therefore depends. However the metrics in the Burst Gap Loss block
or burst gap discard block may be used independently of the metrics
defined in the first two blocks.
To form an accurate assessment of user quality of experience, it is
therefore necessary to know not just overall rates of packet loss/
discard, but also which frame type were affected. The third block
supports the reporting of detailed statistics for each frame type,
including the number of received, lost and discarded of each frame
type in the Group of Pictures and additional data allowing the
calculation of statistical parameters (e.g.,the proportion of each
frame type impaired by packet loss and discard). The metrics defined
in this block belong to the class of application layer metrics
defined in [MONARCH].
2. Terminology
2.1. Standards Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
In addition, the following terms are defined:
Picture Type
Picture types used in the different video algorithms compose of
the key-frame and the Derivation frame. Key-frame is also called
a reference frame and used as a reference for predicting other
pictures. It is coded without prediction from other pictures.
The Derivation frame is derived from Key-frame using prediction
from the reference frame.
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3. Transport Layer Metrics
3.1. Burst/Gap Loss Summary Statistics Block
The metrics described here are intended to be used as described in
this section, in conjunction with information from the Measurement
Information block [MEASIDENT] (which MUST be present in the same RTCP
packet as the Burst/Gap Loss block) and also with the metric
"cumulative number of packets lost" provided in standard RTCP
[RFC3550].
These metrics provide information relevant to statistical parameters,
including burst loss rate, gap loss rate, burst duration mean, burst
duration variance and are calculated using burst gap loss metrics
defined in [BGLOSS] and other information which is sent together with
this report block.
3.1.1. Report Block Structure
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BT=BGLSS | I | rsv. | block length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Burst Loss Rate | Gap Loss Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Burst duration Mean | Burst duration Varianc |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.1.2. Definition of Fields in Loss Summary Statistics Block
Block Type (BT): 8 bits
Burst/Gap Loss Summary Statistics Block is identified by the
constant <BGLSS>.
Interval Metric flag (I): 2 bits
This field is used to indicate whether the Burst/Gap Loss Summary
Statistics metrics are Sampled, Interval or Cumulative metrics,
that is, whether the reported values applies to the most recent
measurement interval duration between successive metrics reports
(I=10) (the Interval Duration) or to the accumulation period
characteristic of cumulative measurements (I=11) (the Cumulative
Duration) or is a sampled instantaneous value (I=01) (Sampled
Value).
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Reserved: 6 bits
This field is reserved for future definition. In the absence of
such a definition, the bits in this field MUST be set to zero and
MUST be ignored by the receiver.
Block Length: 16 bits
The constant 3, in accordance with the definition of this field in
Section 3 of RFC 3611 [RFC3611].
SSRC of Source: 32 bits
As defined in Section 4.1 of RFC3611 [RFC3611].
Burst Loss Rate: 16 bits
The fraction of packets lost during bursts since the beginning of
reception, expressed as a fixed point number with the binary point
at the left edge of the field. This value is calculated by
dividing Packets Loss in Bursts by Total Packets expected in
Bursts as follows:
Packets Loss in Bursts / Total Packets expected in Bursts
Gap Loss Rate: 16 bits
The fraction of packets lost during gaps since the beginning of
reception expressed as a fixed point number with the binary point
at the left edge of the field. This value is calculated by
dividing the difference between number of packets lost and Packets
lost in Bursts by the difference between Packets Expected and
Total Packets expected in Bursts as follows:
(number of packets lost - Packets Lost in Bursts) / (Packets
Expected - Total Packets expected in Bursts)
where "number of packets lost" is obtained from standard RTCP
[RFC3550] and Packets Expected is calculated as the difference
between "extended last sequence number" and "extended first
sequence number" (Interval or Cumulative) provided in the
Measurement Identity and Information block [MEASIDENT].
Note that if the metric is to be calculated on an Interval basis,
a difference must be taken between the current and preceding
values of "cumulative number of packets lost" in RTCP, to obtain
the "number of packets lost" for the reporting interval.
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Burst Duration Mean:16bits
The mean burst duration is obtained as the quotient:
mean = Sum of Burst Durations / Number of Bursts
where " Sum of Burst Durations " and "Number of Bursts"is obtained
from the RTCP XR Burst/Gap Loss Block [BGLOSS].
Burst Duration Variance:16bits
The variance of the burst duration is obtained using the standard
result:
var = ( Sum of Squares of Burst Durations - Number of Bursts *
mean^2 ) / (Number of Bursts - 1)
where " Sum of Squares of Burst Durations " and "Number of
Bursts"is obtained from the RTCP XR Burst/Gap Loss Block [BGLOSS].
3.2. Burst/Gap Discard Summary Statistics Block
The metrics described here are intended to be used as described in
this section, in conjunction with information from the Measurement
Identity block [MEASIDENT] (which MUST be present in the same RTCP
packet as the Burst/Gap Discard block) and also with the metric
"number of packets discarded" provided in the RTCP XR Discard Block
[DISCARD]. The RTCP XR Discard Block SHOULD be sent if the Burst/Gap
Discard block is sent, but the converse does not apply.
These metrics provide information relevant to statistical parameters,
including burst discard rate, gap discard rate and are calculated
using burst gap loss metrics defined in [BGDISCARD] and other
information which is sent together with this report block.
3.2.1. Report Block Structure
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BT=BGDSS | I | Rsv. | block length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Burst Discard Rate | Gap Discard Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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3.2.2. Definition of Fields in Discard Summary Statistics Block
Block Type (BT): 8 bits
Burst/Gap Discard Summary Statistics Block is identified by the
constant <BGDSS>.
Reserved: 8 bits
This field is reserved for future definition. In the absence of
such a definition, the bits in this field MUST be set to zero and
MUST be ignored by the receiver.
Interval Metric flag (I): 2 bits
This field is used to indicate whether the metrics block is an
Interval or a Cumulative report,
Reserved: 6 bits
This field is used to indicate whether the Burst/Gap Discard
Summary Statistics metrics are Sampled, Interval or Cumulative
metrics, that is, whether the reported values applies to the most
recent measurement interval duration between successive metrics
reports (I=10) (the Interval Duration) or to the accumulation
period characteristic of cumulative measurements (I=11) (the
Cumulative Duration) or is a sampled instantaneous value (I=01)
(Sampled Value).
block length: 16 bits
The constant 2, in accordance with the definition of this field in
Section 3 of RFC 3611 [RFC3611].
SSRC of Source: 32 bits
As defined in Section 4.1 of RFC3611 [RFC3611].
Burst Discard Rate: 16 bits
The fraction of packets discarded during bursts since the
beginning of reception, expressed as a fixed point number with the
binary point at the left edge of the field. This value is
calculated by dividing Packets Discarded in Bursts by Total
Packets expected in Bursts as follows:
Packets Discarded in Bursts / Total Packets expected in Bursts
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Gap Discard Rate: 16 bits
The fraction of packets discarded during gaps since the beginning
of reception expressed as a fixed point number with the binary
point at the left edge of the field. This value is calculated by
dividing the difference between number of packets discarded and
Packets Discarded in Bursts by the difference between Packets
Expected and Total Packets expected in Bursts as follows:
(number of packets discarded - Packets Discarded in Bursts) /
(Packets Expected - Total Packets expected in Bursts)
where "number of packets discarded" is obtained from the RTCP XR
Discard Block [DISCARD] and Packets Expected is calculated as the
difference between "extended last sequence number" and "extended
first sequence number" (Interval or Cumulative) provided in the
Measurement Information block [MEASIDENT].
4. Application Layer Metrics
4.1. Frame Impairment Statistics Summary Block
This block reports statistics on which frame type were affected
beyond the information carried in the Statistics Summary Report Block
RTCP packet specified in the section 4.6 of RFC 3611 [RFC3611].
Information is recorded about umber of frames received, lost frames
,duplicated frames, lost partial frames. Such information can be
useful for network management and video quality monitoring.
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4.1.1. Report Block Structure
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BT=FISS |T| rsv. | block length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| begin_seq | end_seq |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of frames received |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| dicarded_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| dup_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| lost_full_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| lost_partial_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.1.2. Definition of Fields in Frame Impairment Summary Statistics
Block
Block type (BT): 8 bits
Frame Impairment Statistics Summary Block is identified by the
constant <FISS>.
Picture type indicator (T): 1 bit
Picture types used in the different video algorithms compose of
key-frame and derivation frame. This field is used to indicate
the frame type to be reported. Bits set to 0 if the lost_frames
field or dup_frames field contain a key_frame report or reference
frame report, 1 if the lost_frames field and dup_frames field
contain other derivation frame report. Note that if both the key
frame report and derivation frame are sent, they should be sent in
the same RTCP compound packet using two XR Blocks.
Rsv.: 7 bits
This field is reserved for future definition. In the absence of
such a definition, the bits in this field MUST be set to zero and
MUST be ignored by the receiver.
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Block Length: 16 bits
The constant 7, in accordance with the definition of this field in
Section 3 of RFC 3611 [RFC3611].
SSRC of Source: 32 bits
As defined in Section 4.1 of RFC3611 [RFC3611].
begin_seq: 16 bits
As defined in Section 4.1 of RFC 3611 [RFC3611].
end_seq: 16 bits
As defined in Section 4.1 of RFC 3611 [RFC3611].
number of frames received:32bits
A count of the number of frames received, estimated if necessary.
If no frames have been received then this count shall be set to
Zero.
lost_full_frames: 32 bits
If one frame is completely lost, this frame is regarded as one
lost full_frame. The lost_full_frames is equivalent to the number
of lost_full_frames in the above sequence number interval.
discarded_frames: 32 bits
Number of frames discarded in the above sequence number interval.
dup_frames: 32 bits
Number of duplicated frames in the above sequence number interval.
lost_partial_frames: 32 bits
If one frame is partially lost, this frame is regarded as one lost
fractional frame. The lost_partial_frames is equivalent to the
number of lost_partial_frames in the above sequence number
interval.
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5. SDP Signaling
[RFC3611] defines the use of SDP (Session Description Protocol)
[RFC4566] for signaling the use of XR blocks. XR blocks MAY be used
without prior signaling.
This section augments the SDP [RFC4566] attribute "rtcp-xr" defined
in [RFC3611] by providing three additional value of "xr-format" to
signal the use of the report block defined in this document.
rtcp-xr-attrib = "a=rtcp-xr:"
[xr-format *(SP xr-format)] CRLF
xr-format =
/ burst-gap-loss-stat
/ burst-gap-discard-stat
/ frame-impairment-stat
Refer to Section 5.1 of RFC 3611 [RFC3611] for a detailed description
and the full syntax of the "rtcp-xr" attribute.
6. IANA Considerations
New block types for RTCP XR are subject to IANA registration. For
general guidelines on IANA considerations for RTCP XR, refer
to[RFC3611] .
6.1. New RTCP XR Block Type values
This document assigns three new block type value in the RTCP XR Block
Type Registry:
Name: BGLSS
Long Name: Burst/Gap Loss Summsary Statistics Block
Value <BGLSS>
Reference: Section 5.1
Name: BGDSS
Long Name: Burst/Gap Discard Summary Statistics Block
Value <BGDSS>
Reference: Section 5.2
Name: FISS
Long Name: Frame Impairment Statistics Summary
Value <FISS>
Reference: Section 6.1
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6.2. New RTCP XR SDP Parameters
This document also registers three new SDP [RFC4566] parameters for
the "rtcp-xr" attribute in the RTCP XR SDP Parameters Registry:
* " burst-gap-loss-stat "
* " burst-gap-discard-stat "
* " frame-impairment-stat "
6.3. Contact information for registrations
The contact information for the registrations is:
Glen Zorn
Network Zen
227/358 Thanon Sanphawut
Bang Na, Bangkok 10110
Thailand
7. Security Considerations
The new RTCP XR report blocks proposed in this document introduces no
new security considerations beyond those described in [RFC3611].
8. Acknowledgements
The authors would like to thank Bill Ver Steeg, David R Oran, Ali
Begen,Colin Perkins, Roni Even,Youqing Yang, Wenxiao Yu, Yinliang
Hu,Jing Zhao and Brandenburg, R. (Ray) van for their valuable
comments and suggestions on this document.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V.
Jacobson, "RTP: A Transport Protocol for Real-Time
Applications", STD 64, RFC 3550, July 2003.
[RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control
Protocol Extended Reports (RTCP XR)", RFC 3611,
November 2003.
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[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
Description Protocol", RFC 4566, July 2006.
9.2. Informative References
[BGDISCARD]
Hunt, G., "RTCP XR Report Block for Burst Gap Discard
metric Reporting",
ID draft-ietf-xrblock-rtcp-xr-burst-gap-discard-02,
January 2012.
[BGLOSS] Hunt, G., "RTCP XR Report Block for Burst Gap Loss metric
Reporting",
ID draft-ietf-xrblock-rtcp-xr-burst-gap-loss-01,
January 2012.
[DISCARD] Hunt, G., "RTCP XR Report Block for Discard metric
Reporting", ID draft-ietf-xrblock-rtcp-xr-discard-01,
December 2011.
[MEASIDENT]
Wu, Q., "Measurement Identity and information Reporting
using SDES item and XR Block",
ID draft-ietf-xrblock-rtcp-xr-meas-identity-02,
January 2012.
[MONARCH] Wu, Q., "Monitoring Architecture for RTP",
ID draft-ietf-avtcore-monarch-10, February 2012.
[RFC6390] Clark, A., "Framework for Performance Metric Development",
RFC 6390, January 2011.
Appendix A. Change Log
This document is separated from
draft-wu-xrblock-rtcp-xr-quality-monitoring-01 with a few editorial
changes and focuses on loss,duplication, discard, and summary
statistics metrics.
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Authors' Addresses
Glen Zorn
Network Zen
77/440 Soi Phoomjit, Rama IV Road
Phra Khanong, Khlong Toie
Bangkok 10110
Thailand
Phone: +66 (0) 87 502 4274
Email: gwz@net-zen.net
Roland Schott
Deutsche Telekom
Deutsche-Telekom-Allee 7
Darmstadt 64295
Germany
Email: Roland.Schott@telekom.de
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: sunseawq@huawei.com
Rachel Huang
Huawei
101 Software Avenue, Yuhua District
Nanjing 210012
China
Email: Rachel@huawei.com
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