draft-ietf-xrblock-rtcp-xr-pdv-00.txt   draft-ietf-xrblock-rtcp-xr-pdv-01.txt 
Audio/Video Transport Working Group G. Hunt Audio/Video Transport Working Group G. Hunt
Internet-Draft Unaffiliated Internet-Draft Unaffiliated
Intended status: Standards Track A. Clark Intended status: Standards Track A. Clark
Expires: March 29, 2012 Telchemy Expires: April 30, 2012 Telchemy
Q. Wu Q. Wu
Huawei Huawei
September 26, 2011 October 28, 2011
RTCP XR Report Block for Packet Delay Variation Metric Reporting RTCP XR Report Block for Packet Delay Variation Metric Reporting
draft-ietf-xrblock-rtcp-xr-pdv-00.txt draft-ietf-xrblock-rtcp-xr-pdv-01.txt
Abstract Abstract
This document defines an RTCP XR Report Block that allows the This document defines an RTCP XR Report Block that allows the
reporting of Packet Delay Variation metrics for a range of RTP reporting of Packet Delay Variation metrics for a range of RTP
applications. 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 March 29, 2012. This Internet-Draft will expire on April 30, 2012.
Copyright Notice Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the Copyright (c) 2011 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 32 skipping to change at page 2, line 32
5.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 12 5.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 12
5.3. Contact information for registrations . . . . . . . . . . 12 5.3. Contact information for registrations . . . . . . . . . . 12
5.4. New registry of PDV types . . . . . . . . . . . . . . . . 12 5.4. New registry of PDV types . . . . . . . . . . . . . . . . 12
6. Security Considerations . . . . . . . . . . . . . . . . . . . 14 6. Security Considerations . . . . . . . . . . . . . . . . . . . 14
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7.1. Normative References . . . . . . . . . . . . . . . . . . . 15 7.1. Normative References . . . . . . . . . . . . . . . . . . . 15
7.2. Informative References . . . . . . . . . . . . . . . . . . 15 7.2. Informative References . . . . . . . . . . . . . . . . . . 15
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 16 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 16
A.1. draft-ietf-avt-rtcp-xr-pdv-03 . . . . . . . . . . . . . . 16 A.1. draft-ietf-avt-rtcp-xr-pdv-03 . . . . . . . . . . . . . . 16
A.2. draft-ietf-xrblock-rtcp-xr-pdv-00 . . . . . . . . . . . . 16 A.2. draft-ietf-xrblock-rtcp-xr-pdv-00 . . . . . . . . . . . . 16
A.3. draft-ietf-xrblock-rtcp-xr-pdv-01 . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction 1. Introduction
1.1. Packet Delay Variation Metrics Block 1.1. Packet Delay Variation Metrics 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. [RFC3611], for use in a range of RTP applications.
The new block type provides information on Packet Delay Variation The new block type provides information on Packet Delay Variation
skipping to change at page 4, line 18 skipping to change at page 4, line 18
used is used is
Numeric formats S X:Y Numeric formats S X:Y
where S indicates a two's complement signed representation, X where S indicates a two's complement signed representation, X
the number of bits prior to the decimal place and Y the number the number of bits prior to the decimal place and Y the number
of bits after the decimal place. of bits after the decimal place.
Hence 8:8 represents an unsigned number in the range 0.0 to Hence 8:8 represents an unsigned number in the range 0.0 to
255.996 with a granularity of 0.0039. S7:8 would represent the 255.996 with a granularity of 0.0039. S7:8 would represent the
range -128.000 to +127.996. 0:16 represents a proper binary range -127.996 to +127.996. 0:16 represents a proper binary
fraction with range fraction with range
0.0 to 1 - 1/65536 = 0.9999847 0.0 to 1 - 1/65536 = 0.9999847
though note that use of flag values at the top of the numeric though note that use of flag values at the top of the numeric
range slightly reduces this upper limit. For example, if the range slightly reduces this upper limit. For example, if the
16- bit values 0xfffe and 0xffff are used as flags for "over- 16- bit values 0xfffe and 0xffff are used as flags for "over-
range" and "unavailable" conditions, a 0:16 quantity has range range" and "unavailable" conditions, a 0:16 quantity has range
0.0 to 1 - 3/65536 = 0.9999542 0.0 to 1 - 3/65536 = 0.9999542
skipping to change at page 5, line 21 skipping to change at page 5, line 21
PDV metrics block PDV metrics block
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BT=NPDV |I|pdvtyp | Rsv.| block length=3 | | BT=NPDV |I|pdvtyp | Rsv.| block length=3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source | | SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pos Threshold/Peak PDV | Pos PDV Percentile | | Pos PDV Threshold/Peak | Pos PDV Percentile |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Neg Threshold/Peak PDV | Neg PDV Percentile | | Neg PDV Threshold/Peak | Neg PDV Percentile |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Mean PDV | unused | | Mean PDV | unused |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Report Block Structure Figure 1: Report Block Structure
3.2. Definition of Fields in PDV Metrics Block 3.2. Definition of Fields in PDV Metrics Block
Block type (BT): 8 bits Block type (BT): 8 bits
skipping to change at page 5, line 48 skipping to change at page 6, line 4
RTCP XR block type for this block.] RTCP XR block type for this block.]
Interval Metric flag (I): 1 bit Interval Metric flag (I): 1 bit
This field is used to indicate whether the Packet Delay Variation This field is used to indicate whether the Packet Delay Variation
metrics block is an Interval or a Cumulative report, that is, metrics block is an Interval or a Cumulative report, that is,
whether the reported values apply to the most recent measurement whether the reported values apply to the most recent measurement
interval duration between successive metrics reports (I=1) (the interval duration between successive metrics reports (I=1) (the
Interval Duration) or to the accumulation period characteristic of Interval Duration) or to the accumulation period characteristic of
cumulative measurements (I=0) (the Cumulative Duration). cumulative measurements (I=0) (the Cumulative Duration).
Numerical values for both these intervals are provided in the
Measurement Identifier block referenced by the tag field below.
Packet Delay Variation Metric Type (pdvtyp): 4 bits Packet Delay Variation Metric Type (pdvtyp): 4 bits
This field is used to identify the Packet Delay Variation Metric This field is used to identify the Packet Delay Variation Metric
Type used in this report block, according to the following code: Type used in this report block, according to the following code:
bits 014-017 bits 014-017
0: interarrival jitter, Section 6.4.1 of [RFC3550], 0: interarrival jitter, Section 6.4.1 of [RFC3550],
skipping to change at page 7, line 17 skipping to change at page 7, line 17
The percentages of packets in the RTP stream for which individual The percentages of packets in the RTP stream for which individual
packet delays were less than the Positive PDV Threshold. It is packet delays were less than the Positive PDV Threshold. It is
expressed in numeric format 8:8 with values from 0 to 100th expressed in numeric format 8:8 with values from 0 to 100th
percentile. percentile.
If the measurement is unavailable, the value 0xFFFF SHOULD be If the measurement is unavailable, the value 0xFFFF SHOULD be
reported. reported.
Negative PDV Threshold/Peak: 16 bits Negative PDV Threshold/Peak: 16 bits
The percentages of packets in the RTP stream for which individual This field is associated with the Negative PDV percentile and
packet delays were more than the Negative PDV Threshold. It is expressed in Milliseconds with numeric format S11:4. The term
expressed in numeric format 8:8 with values from 0 to 100th Negative represents that the packets are arriving earlier than the
percentile. expected time.
If the measured value is more negative than -2047.9375 (the value If the measured value is more negative than -2047.9375 (the value
which would be coded as 0x8001), the value 0x8000 SHOULD be which would be coded as 0x8001), the value 0x8000 SHOULD be
reported to indicate an over-range negative measurement. If the reported to indicate an over-range negative measurement. If the
measured value is more positive than +2047.8125 (the value which measured value is more positive than +2047.8125 (the value which
would be coded as 0x7FFD), the value 0x7FFE SHOULD be reported to would be coded as 0x7FFD), the value 0x7FFE SHOULD be reported to
indicate an over-range positive measurement. If the measurement indicate an over-range positive measurement. If the measurement
is unavailable, the value 0x7FFF SHOULD be reported. is unavailable, the value 0x7FFF SHOULD be reported.
Negative PDV Percentile: 16 bits Negative PDV Percentile: 16 bits
skipping to change at page 9, line 34 skipping to change at page 9, line 34
is likely to be useful in networks which use fixed de-jitter is likely to be useful in networks which use fixed de-jitter
buffering, because it may be used to determine the length of the buffering, because it may be used to determine the length of the
required de-jitter buffer, or to determine if network performance has required de-jitter buffer, or to determine if network performance has
deteriorated such that existing de-jitter buffers are too small to deteriorated such that existing de-jitter buffers are too small to
accommodate the observed delay variation. accommodate the observed delay variation.
3.4. Examples of use 3.4. Examples of use
(a) To report interarrival jitter [RFC3550]: (a) To report interarrival jitter [RFC3550]:
Threshold PDV = FFFF (Undefined); PDV Percentile = FFFF PDV Threshold = FFFF (Undefined); PDV Percentile = FFFF
(Undefined); PDV type = 0 (interarrival jitter) (Undefined); PDV type = 0 (interarrival jitter)
causes interarrival jitter to be reported in the Mean PDV causes interarrival jitter to be reported in the Mean PDV
field. field.
(b) To report MAPDV2 [G.1020]: (b) To report MAPDV2 [G.1020]:
Pos Threshold PDV = 50.0; Pos PDV Percentile = 95.3; Neg Pos PDV Threshold = 50.0; Pos PDV Percentile = 95.3; Neg PDV
Threshold PDV = 50.0 (note this implies -50ms); Neg PDV Threshold = 50.0 (note this implies -50ms); Neg PDV Percentile
Percentile = 98.4; PDV type = 1 (MAPDV2) = 98.4; PDV type = 1 (MAPDV2)
causes average MAPDV2 to be reported in the Mean PDV field. causes average MAPDV2 to be reported in the Mean PDV field.
Note that implementations may either fix the reported Note that implementations may either fix the reported
percentile and calculate the associated PDV level or may fix a percentile and calculate the associated PDV level or may fix a
threshold PDV level and calculate the associated percentile. threshold PDV level and calculate the associated percentile.
From a practical implementation perspective it is simpler to From a practical implementation perspective it is simpler to
use the second of these approaches (except of course in the use the second of these approaches (except of course in the
extreme case of a 100% percentile). extreme case of a 100% percentile).
skipping to change at page 11, line 40 skipping to change at page 11, line 40
fixpoint = 1*DIGIT "." 1*DIGIT ; fixed point decimal fixpoint = 1*DIGIT "." 1*DIGIT ; fixed point decimal
DIGIT = %x30-39 DIGIT = %x30-39
When SDP is used in offer-answer, a system sending SDP may request a When SDP is used in offer-answer, a system sending SDP may request a
specific type of PDV measurement. In addition, they may state a specific type of PDV measurement. In addition, they may state a
specific percentile or threshold value, and expect to receive the specific percentile or threshold value, and expect to receive the
corresponding threshold or percentile metric, respectively. The corresponding threshold or percentile metric, respectively. The
system receiving the SDP SHOULD send the PDV metrics requested, but system receiving the SDP SHOULD send the PDV metrics requested, but
if the metric is not available, the system receiving the SDP SHOULD if the metric is not available, the system receiving the SDP SHOULD
send the flag value indicating that the metric is unavailable. send the metric block with the flag value indicating that the metric
is unavailable.
5. IANA Considerations 5. IANA Considerations
New block types for RTCP XR are subject to IANA registration. For New block types for RTCP XR are subject to IANA registration. For
general guidelines on IANA considerations for RTCP XR, refer to general guidelines on IANA considerations for RTCP XR, refer to
[RFC3611]. [RFC3611].
5.1. New RTCP XR Block Type value 5.1. New RTCP XR Block Type value
This document assigns the block type value NPDV in the IANA "RTCP XR This document assigns the block type value NPDV in the IANA "RTCP XR
skipping to change at page 17, line 5 skipping to change at page 16, line 26
o Updated references. o Updated references.
A.2. draft-ietf-xrblock-rtcp-xr-pdv-00 A.2. draft-ietf-xrblock-rtcp-xr-pdv-00
The following are the major changes to previous version The following are the major changes to previous version
draft-ietf-avt-rtcp-xr-pdv-03 : draft-ietf-avt-rtcp-xr-pdv-03 :
o Updated references. o Updated references.
A.3. draft-ietf-xrblock-rtcp-xr-pdv-01
The following are the major changes to previous version
draft-ietf-xrblock-rtcp-xr-pdv-00 :
o Fix typos or nits in the definition of Negative PDV Threshold/
Peak.
o Fix nits in Numeric format S7:8.
o remove the text that is relevant to tag field.
o Add text in SDP signaling section to clarify indicationof metric
unavailable.
Authors' Addresses Authors' Addresses
Geoff Hunt Geoff Hunt
Unaffiliated Unaffiliated
Email: r.geoff.hunt@gmail.com Email: r.geoff.hunt@gmail.com
Alan Clark Alan Clark
Telchemy Incorporated Telchemy Incorporated
2905 Premiere Parkway, Suite 280 2905 Premiere Parkway, Suite 280
 End of changes. 14 change blocks. 
18 lines changed or deleted 33 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/