draft-ietf-xrblock-rtcp-xr-jb-14.txt   rfc7005.txt 
Audio/Video Transport Working Group A. Clark Internet Engineering Task Force (IETF) A. Clark
Internet-Draft Telchemy Request for Comments: 7005 Telchemy
Intended status: Standards Track V. Singh Category: Standards Track V. Singh
Expires: December 30, 2013 Aalto University ISSN: 2070-1721 Aalto University
Q. Wu Q. Wu
Huawei Huawei
June 28, 2013 September 2013
RTP Control Protocol (RTCP) Extended Report (XR) Block for De-Jitter RTP Control Protocol (RTCP) Extended Report (XR) Block
Buffer Metric Reporting for De-Jitter Buffer Metric Reporting
draft-ietf-xrblock-rtcp-xr-jb-14.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 De-Jitter Buffer metrics for (XR) block that allows the reporting of de-jitter buffer metrics for
a range of RTP applications. a range of RTP applications.
Status of this Memo Status of This Memo
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provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering This is an Internet Standards Track document.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. De-Jitter Buffer Metrics Block . . . . . . . . . . . . . . 3 1.1. De-Jitter Buffer Metrics Block . . . . . . . . . . . . . . 3
1.2. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . . 3 1.2. RTCP and RTCP Extended 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. Standards Language . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 4 3. De-Jitter Buffer Operation . . . . . . . . . . . . . . . . . . 4
3. De-Jitter Buffer Operation . . . . . . . . . . . . . . . . . . 5 3.1. Idealized De-Jitter Buffer . . . . . . . . . . . . . . . . 4
3.1. Idealized De-Jitter Buffer . . . . . . . . . . . . . . . . 5 3.2. Fixed De-Jitter Buffer . . . . . . . . . . . . . . . . . . 5
3.2. Fixed De-Jitter Buffer . . . . . . . . . . . . . . . . . . 6 3.3. Adaptive De-Jitter Buffer . . . . . . . . . . . . . . . . 5
3.3. Adaptive De-Jitter Buffer . . . . . . . . . . . . . . . . 6 4. De-Jitter Buffer Metrics Block . . . . . . . . . . . . . . . . 6
4. De-Jitter Buffer Metrics Block . . . . . . . . . . . . . . . . 7 4.1. Report Block Structure . . . . . . . . . . . . . . . . . . 6
4.1. Report Block Structure . . . . . . . . . . . . . . . . . . 7 4.2. Definition of Fields in De-Jitter Buffer Metrics Block . . 6
4.2. Definition of Fields in De-Jitter Buffer Metrics Block . . 7 5. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 9
5. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 11 5.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 9
5.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 11 5.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 9
5.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 11 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 6.1. New RTCP XR Block Type Value . . . . . . . . . . . . . . . 9
6.1. New RTCP XR Block Type value . . . . . . . . . . . . . . . 12 6.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 10
6.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 12 6.3. Contact Information for Registrations . . . . . . . . . . 10
6.3. Contact information for registrations . . . . . . . . . . 12 7. Security Considerations . . . . . . . . . . . . . . . . . . . 10
7. Security Considerations . . . . . . . . . . . . . . . . . . . 13 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 10
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 14 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 10.1. Normative References . . . . . . . . . . . . . . . . . . . 10
10.1. Normative References . . . . . . . . . . . . . . . . . . . 16 10.2. Informative References . . . . . . . . . . . . . . . . . . 11
10.2. Informative References . . . . . . . . . . . . . . . . . . 16 Appendix A. Metrics Represented Using the Template from
Appendix A. Metrics represented using RFC6390 Template . . . . . 17 RFC 6390 . . . . . . . . . . . . . . . . . . . . . . 12
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 20
B.1. draft-ietf-xrblock-rtcp-xr-jb-12 . . . . . . . . . . . . . 20
B.2. draft-ietf-xrblock-rtcp-xr-jb-11 . . . . . . . . . . . . . 20
B.3. draft-ietf-xrblock-rtcp-xr-jb-10 . . . . . . . . . . . . . 20
B.4. draft-ietf-xrblock-rtcp-xr-jb-09 . . . . . . . . . . . . . 20
B.5. draft-ietf-xrblock-rtcp-xr-jb-08 . . . . . . . . . . . . . 20
B.6. draft-ietf-xrblock-rtcp-xr-jb-07 . . . . . . . . . . . . . 20
B.7. draft-ietf-xrblock-rtcp-xr-jb-05 . . . . . . . . . . . . . 21
B.8. draft-ietf-xrblock-rtcp-xr-jb-03 . . . . . . . . . . . . . 21
B.9. draft-ietf-xrblock-rtcp-xr-jb-02 . . . . . . . . . . . . . 21
B.10. draft-ietf-xrblock-rtcp-xr-jb-01 . . . . . . . . . . . . . 21
B.11. draft-ietf-xrblock-rtcp-xr-jb-00 . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction 1. Introduction
1.1. De-Jitter Buffer Metrics Block 1.1. De-Jitter Buffer Metrics Block
This document defines a new block type to augment those defined in This document 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 jitter buffer The new block type provides information on de-jitter buffer
configuration and performance. configuration and performance.
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].
Instances of this metrics block refer by Synchronization source Instances of this metrics block refer by synchronization source
(SSRC) to the separate auxiliary Measurement Information block (SSRC) to the separate auxiliary Measurement Information Block
[RFC6776] which contains information such as the SSRC of the measured [RFC6776], which contains information such as the SSRC of the
stream, and RTP sequence numbers and time intervals indicating the measured stream, and RTP sequence numbers and time intervals
span of the report. indicating the span of the report.
1.2. RTCP and RTCP XR 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]
defines an extensible structure for reporting using an RTCP Extended defines 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
The Performance Metrics Framework [RFC6390] provides guidance on the "Guidelines for Considering New Performance Metric Development"
definition and specification of performance metrics. The RTP [RFC6390] provides guidance on the definition and specification of
Monitoring Architectures [RFC6792] provides guideline for reporting performance metrics. "Guidelines for Use of the RTP Monitoring
block format using RTCP XR. Metrics described in this draft are in Framework" [RFC6792] provides guidance on the reporting block format
accordance with the guidelines in [RFC6390]and [RFC6792]. using RTCP XR. Metrics described in this document are in accordance
with the guidelines in [RFC6390]and [RFC6792].
1.4. Applicability 1.4. Applicability
Real-time applications employ a de-jitter buffer [RFC5481] to absorb Real-time applications employ a de-jitter buffer [RFC5481] to absorb
jitter introduced on the path from source to destination. These jitter introduced on the path from source to destination. These
metrics are used to report how the de-jitter buffer at the receiving metrics are used to report how the de-jitter buffer at the receiving
end of RTP stream behaves as a result of jitter in the network; and end of the RTP stream behaves as a result of jitter in the network;
they are applicable to a range of RTP applications. they are applicable to a range of RTP applications.
These metrics are corresponding to terminal related factors that These metrics correspond to terminal-related factors that affect
affect real-time application quality and are useful to provide better real-time application quality and are useful for providing a better
end-user quality of experience (QoE) when these terminal-related end-user quality of experience (QoE) when these terminal-related
factors are used as inputs to calculate QoE metrics [QMB]. factors are used as inputs to calculate QoE metrics [QMB].
2. Terminology 2. 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].
3. De-Jitter Buffer Operation 3. De-Jitter Buffer Operation
A de-jitter buffer is required to absorb delay variation in network A de-jitter buffer is required to absorb delay variation in the
delivery of media packets. A de-jitter buffer works by holding media network delivery of media packets. A de-jitter buffer works by
data for a period of time after it is received and before it is holding media data for a period of time after it is received and
played out. Packets that arrive early are held in the de-jitter before it is played out. Packets that arrive early are held in the
buffer longer. If packets arrive too early they may be discarded if de-jitter buffer longer. If packets arrive too early, they may be
there is no available de-jitter buffer space. If packets are delayed discarded if there is no available de-jitter buffer space. If
excessively by the network they may be discarded if they miss their packets are delayed excessively by the network, they may be discarded
playout time. if they miss their playout time.
The de-jitter buffer can be considered as a time window with early The de-jitter buffer can be considered a time window with the early
edge aligned with the delay corresponding to the earliest arriving edge aligned with the delay corresponding to the earliest arriving
packet and late edge representing the maximum permissible delay packet and the late edge representing the maximum permissible delay
before a late arriving packet would be discarded. The delay applied before a late arriving packet would be discarded. The delay applied
to packets that arrive on time or at their expected arrival time is to packets that arrive on time or at their expected arrival time is
known as the Nominal Delay and this is equivalent to the time known as the nominal delay, and this is equivalent to the time
difference/ buffer size difference between the on-time packets difference/buffer size difference between the insertion point of the
insertion point and the point at which packets are read out. on-time packets and the point at which the packets are read out.
The reference for the expected arrival time may, for example, be the The reference for the expected arrival time may be, for example, the
first packet in the session or the running average delay. If all first packet in the session or the running average delay. If all
packets arrived at their expected arrival time, then every packet packets arrived at their expected arrival time, then every packet
would be held in the de-jitter buffer exactly the Nominal Delay. would be held in the de-jitter buffer exactly the nominal delay.
The de-jitter buffer maximum delay is the delay that is applied to an The de-jitter buffer maximum delay is the delay that is applied to
earliest arriving packet that is not discarded and corresponds to the the earliest arriving packet that is not discarded and corresponds to
early edge of the de-jitter buffer time window. the early edge of the de-jitter buffer time window.
3.1. Idealized De-Jitter Buffer 3.1. Idealized De-Jitter Buffer
In practice de-jitter buffer implementations vary considerably In practice, de-jitter buffer implementations vary considerably;
however they should behave in a manner conceptually consistent with however, they should behave in a manner conceptually consistent with
an idealized de-jitter buffer described as follows: an idealized de-jitter buffer, which is described as follows:
(i). Receive the first packet and delay playout by D ms. Keep (i) Receive the first packet and delay playout by D ms. Keep the
the RTP timestamp and receive time as a reference. RTP timestamp (TS) and receive time as a reference.
RTP Timestamp(TS)[1] RTP TS[1]
receive time[1] receive time[1]
Assume that both are normalized in ticks (there are 10 000 ticks Assume that both are normalized in ticks (there are 10,000
in a millisecond). ticks in a millisecond).
(ii). Receive the next packet (ii) Receive the next packet.
(iii). Calculate r = RTP TS[n] - RTP TS[1] and t = receive
time[n] - receive time[1]. If r == t then the packet arrived on
time. If r < t then the packet arrived late and if r > t then the
packet arrived early.
(iv). Delay playout of packet by D + (r-t) (iii) Calculate r = RTP TS[n] - RTP TS[1] and t = receive time[n] -
receive time[1]. If r == t, then the packet arrived on time.
If r < t, then the packet arrived late, and if r > t, then the
packet arrived early.
(v). Go back to (ii) (iv) Delay playout of packet by D + (r-t).
(v) Go back to (ii).
Note that this idealized implementation assumes that the sender's RTP Note that this idealized implementation assumes that the sender's RTP
clock is synchronized to the clock in the receiver which is used to clock is synchronized to the clock in the receiver, which is used to
timestamp packet arrivals. If there is no such inherent timestamp packet arrivals. If there is no such inherent
synchronization, the system may need to use an adaptive de-jitter synchronization, the system may need to use an adaptive de-jitter
buffer or other techniques to ensure reliable reception. buffer or other techniques to ensure reliable reception.
3.2. Fixed De-Jitter Buffer 3.2. Fixed De-Jitter Buffer
A fixed de-jitter buffer lacks provision to track network condition A fixed de-jitter buffer lacks provision to track the condition of
and has a fixed size and packets leaving the de-jitter buffer have a the network and has a fixed size, and packets leaving the de-jitter
constant delay. For fixed de-jitter buffer implementation, the buffer have a constant delay. For fixed de-jitter buffer
nominal delay is set to a constant value corresponding to the packets implementation, the nominal delay is set to a constant value
that arrive at their expected arrival time while the maximum delay is corresponding to the packets that arrive at their expected arrival
set to a constant value corresponding to the fixed size of the de- time, while the maximum delay is set to a constant value
jitter buffer. corresponding to the fixed size of the de-jitter buffer.
3.3. Adaptive De-Jitter Buffer 3.3. Adaptive De-Jitter Buffer
An adaptive de-jitter buffer can adapt to the change in the network's An adaptive de-jitter buffer can adapt to the change in the network's
delay and has variable size or variable delay. It allows the nominal delay and has variable size or variable delay. It allows the nominal
delay to be set to a low value initially, to minimize user perceived delay to be set to a low value initially to minimize user perceived
delay, however can automatically extend the late edge (and possibly delay; however, it can automatically extend the late edge (and
also retract the early edge) of buffer window if a significant possibly also retract the early edge) of a buffer window if a
proportion of packets are arriving late (and hence being discarded). significant proportion of the packets are arriving late (and hence
being discarded).
4. De-Jitter Buffer Metrics Block 4. De-Jitter Buffer Metrics Block
This block describes the configuration and operating parameters of This block describes the configuration and operating parameters of
the de-jitter buffer in the receiver of the RTP end system or RTP the de-jitter buffer in the receiver of the RTP end system or RTP
mixer which sends the report. Instances of this metrics block refer mixer that sends the report. Instances of this metrics block use the
by SSRC to the separate auxiliary Measurement Information Block SSRC to refer to the separate auxiliary Measurement Information Block
[RFC6776] which describes the measurement interval in use. This [RFC6776], which describes the measurement periods in use (see
metrics block relies on the measurement interval in the Measurement [RFC6776], Section 4.2). This metrics block relies on the
Information Block indicating the span of the report and MUST be sent measurement interval in the Measurement Information Block indicating
in the same compound RTCP packet as the Measurement Information the span of the report and MUST be sent in the same compound RTCP
Block. If the measurement interval is not received in the same packet as the Measurement Information Block. If the measurement
compound RTCP packet as this metrics block, this metrics block MUST interval is not received in the same compound RTCP packet as this
be discarded. metrics block, this metrics block MUST be discarded.
4.1. Report Block Structure 4.1. Report Block Structure
De-Jitter Buffer (DJB) Metrics Block De-Jitter Buffer (DJB) 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=DJB | I |C| Rsvd. | block length=3 | | BT=23 | I |C| resv | Block Length=3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source | | SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DJB nominal | DJB maximum | | DJB nominal | DJB maximum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DJB high water mark | DJB low water mark | | DJB high-water mark | DJB low-water mark |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Report Block Structure Figure 1: Report Block Structure
4.2. Definition of Fields in De-Jitter Buffer Metrics Block 4.2. Definition of Fields in De-Jitter Buffer Metrics Block
Block type (BT): 8 bits Block Type (BT): 8 bits
A de-jitter buffer Metrics Report Block is identified by the
constant DJB.
[Note to RFC Editor: please replace DJB with the IANA provided A De-Jitter Buffer Metrics Report Block is identified by the
RTCP XR block type for this block.] constant 23.
Interval Metric flag (I): 2 bits Interval Metric flag (I): 2 bits
This field is used to indicate whether the de-jitter buffer This field is used to indicate whether the de-jitter buffer
metrics are Sampled, Interval or Cumulative metrics: metrics are Sampled, Interval, or Cumulative metrics:
I=01: Sampled Value - the reported value is a sampled I=01: Sampled Value - the reported value is a sampled
instantaneous value. instantaneous value.
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.
In this document, de-jitter buffer Metrics can only be sampled , In this document, de-jitter buffer metrics can only be sampled and
and cannot be measured over definite intervals. Also, the value cannot be measured over definite intervals. Also, the value I=00
I=00 is reserved for future use. Senders MUST NOT use the values is reserved for future use. Senders MUST NOT use the values I=00,
I=00 or I=10 or I=11. If a block is received with I=00 or I=10 or I=10, or I=11. If a block is received with I=00, I=10, or I=11,
I=11, the receiver MUST discard the block. the receiver MUST discard the block.
Jitter Buffer Configuration (C): 1 bit Jitter Buffer Configuration (C): 1 bit
This field is used to identify the de-jitter buffer method in use This field is used to identify the de-jitter buffer method in use
at the receiver, according to the following code: at the receiver, according to the following code:
0 = Fixed de-jitter buffer 0 = Fixed de-jitter buffer
1 = Adaptive de-jitter buffer 1 = Adaptive de-jitter buffer
Reserved (Rsvd.): 5 bits Reserved (resv): 5 bits
These bits are reserved. They MUST be set to zero by senders These bits are reserved. They MUST be set to zero by senders and
ignored by receivers (See [RFC6709] section 4.2). ignored by receivers (see [RFC6709], Section 4.2).
Block Length: 16 bits Block Length: 16 bits
The length of this report block in 32-bit words, minus one, in The length of this report block in 32-bit words, minus one, in
accordance with the definition in [RFC3611]. This field MUST be accordance with the definition in [RFC3611]. This field MUST be
set to 3 to match the fixed length of the report block. set to 3 to match the fixed length of the report block.
de-jitter buffer nominal delay (DJB nominal): 16 bits SSRC of Source: 32 bits
This is the current nominal de-jitter buffer delay in As defined in Section 4.1 of [RFC3611].
milliseconds, which corresponds to the nominal de-jitter buffer
De-jitter buffer nominal delay (DJB nominal): 16 bits
This is the current nominal de-jitter buffer delay (in
milliseconds) that corresponds to the nominal de-jitter buffer
delay for packets that arrive exactly on time. It is calculated delay for packets that arrive exactly on time. It is calculated
based on the time spent in the de-jitter buffer for the packet based on the time spent in the de-jitter buffer for the packet
that arrives exactly on time. This parameter MUST be provided for that arrives exactly on time. This parameter MUST be provided for
both fixed and adaptive de-jitter buffer implementations. both fixed and adaptive de-jitter buffer implementations.
The measured value is unsigned value. If the measured value The measured value is an unsigned value. If the measured value
exceeds 0xFFFD, the value 0xFFFE MUST be reported to indicate an exceeds 0xFFFD, the value 0xFFFE MUST be reported to indicate an
over-range measurement. If the measurement is unavailable, the over-range measurement. If the measurement is unavailable, the
value 0xFFFF MUST be reported. value 0xFFFF MUST be reported.
de-jitter buffer maximum delay (DJB maximum): 16 bits De-jitter buffer maximum delay (DJB maximum): 16 bits
This is the current maximum de-jitter buffer delay in milliseconds This is the current maximum de-jitter buffer delay (in
which corresponds to the earliest arriving packet that would not milliseconds) that corresponds to the earliest arriving packet
be discarded. It is calculated based on the time spent in the de- that would not be discarded. It is calculated based on the time
jitter buffer for the earliest arriving packet In simple queue spent in the de-jitter buffer for the earliest arriving packet.
implementations this may correspond to the size of the de-jitter In simple queue implementations, this may correspond to the size
buffer. In adaptive de-jitter buffer implementations, this value of the de-jitter buffer. In adaptive de-jitter buffer
may vary dynamically. This parameter MUST be provided for both implementations, this value may vary dynamically. This parameter
fixed and adaptive de-jitter buffer implementations. MUST be provided for both fixed and adaptive de-jitter buffer
implementations.
The measured value is unsigned value. If the measured value The measured value is an unsigned value. If the measured value
exceeds 0xFFFD, the value 0xFFFE MUST be reported to indicate an exceeds 0xFFFD, the value 0xFFFE MUST be reported to indicate an
over-range measurement. If the measurement is unavailable, the over-range measurement. If the measurement is unavailable, the
value 0xFFFF MUST be reported. value 0xFFFF MUST be reported.
de-jitter buffer high water mark (DJB high water mark): 16 bits De-jitter buffer high-water mark (DJB high-water mark): 16 bits
This is the highest value of the de-jitter buffer nominal delay in This is the highest value of the de-jitter buffer nominal delay
milliseconds which occurred at any time during the reporting (in milliseconds) that occurred at any time during the reporting
interval. This parameter MUST be provided for adaptive de-jitter interval. This parameter MUST be provided for adaptive de-jitter
buffer implementations and its value MUST be set to JB maximum for buffer implementations, and its value MUST be set to DJB maximum
fixed de-jitter buffer implementations. for fixed de-jitter buffer implementations.
The measured value is unsigned value. If the measured value The measured value is an unsigned value. If the measured value
exceeds 0xFFFD, the value 0xFFFE MUST be reported to indicate an exceeds 0xFFFD, the value 0xFFFE MUST be reported to indicate an
over-range measurement. If the measurement is unavailable, the over-range measurement. If the measurement is unavailable, the
value 0xFFFF MUST be reported. value 0xFFFF MUST be reported.
de-jitter buffer low water mark (DJB low water mark): 16 bits De-jitter buffer low-water mark (DJB low-water mark): 16 bits
This is the lowest value of the de-jitter buffer nominal delay in This is the lowest value of the de-jitter buffer nominal delay (in
milliseconds which occurred at any time during the reporting milliseconds) that occurred at any time during the reporting
interval. This parameter MUST be provided for adaptive de-jitter interval. This parameter MUST be provided for adaptive de-jitter
buffer implementations and its value MUST be set to JB maximum for buffer implementations, and its value MUST be set to DJB maximum
fixed de-jitter buffer implementations. for fixed de-jitter buffer implementations.
The measured value is unsigned value. If the measured value The measured value is an unsigned value. If the measured value
exceeds 0xFFFD, the value 0xFFFE MUST be reported to indicate an exceeds 0xFFFD, the value 0xFFFE MUST be reported to indicate an
over-range measurement. If the measurement is unavailable, the over-range measurement. If the measurement is unavailable, the
value 0xFFFF MUST be reported. value 0xFFFF MUST be reported.
5. SDP Signaling 5. SDP Signaling
[RFC3611] defines the use of SDP (Session Description Protocol) [RFC3611] defines the use of the Session Description Protocol (SDP)
[RFC4566] for signaling the use of XR blocks. However XR blocks MAY [RFC4566] for signaling the use of XR blocks. However, XR blocks MAY
be used without prior signaling (see section 5 of RFC3611). be used without prior signaling (see Section 5 of RFC 3611).
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
in [RFC3611] by providing an additional value of "xr-format" to in [RFC3611] by providing an additional value of "xr-format" to
signal the use of the report block defined in this document. signal the use of the report block defined in this document.
xr-format =/ xr-djb-block xr-format =/ xr-djb-block
xr-djb-block = "de-jitter-buffer" xr-djb-block = "de-jitter-buffer"
5.2. Offer/Answer Usage 5.2. Offer/Answer Usage
When SDP is used in offer-answer context [RFC3264], the SDP Offer/ When SDP is used in Offer/Answer context [RFC3264], the SDP Offer/
Answer usage defined in [RFC3611] for unilateral "rtcp-xr" attribute Answer usage defined in [RFC3611] for unilateral "rtcp-xr" attribute
parameters applies. For detailed usage of Offer/Answer for parameters applies. For detailed usage of Offer/Answer for
unilateral parameter, refer to section 5.2 of [RFC3611]. unilateral parameters, refer to Section 5.2 of [RFC3611].
6. IANA Considerations 6. 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].
6.1. New RTCP XR Block Type value 6.1. New RTCP XR Block Type Value
This document assigns the block type value DJB in the IANA "RTP This document assigns the block type value 23 in the IANA "RTP
Control Protocol Extended Reports (RTCP XR) Block Type Registry" to Control Protocol Extended Reports (RTCP XR) Block Type Registry" to
the "De-Jitter Buffer Metrics Block". the "De-Jitter Buffer Metrics Block".
[Note to RFC Editor: please replace DJB with the IANA provided RTCP
XR block type for this block.]
6.2. New RTCP XR SDP Parameter 6.2. New RTCP XR SDP Parameter
This document also registers a new parameter "de-jitter-buffer" in This document also registers a new parameter "de-jitter-buffer" in
the "RTP Control Protocol Extended Reports (RTCP XR) Session 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 registrations is:
Qin Wu (sunseawq@huawei.com) Qin Wu (sunseawq@huawei.com)
101 Software Avenue, Yuhua District 101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012 Nanjing, Jiangsu 210012
China China
7. Security Considerations 7. Security Considerations
It is believed that this proposed RTCP XR report block introduces no It is believed that this RTCP XR block introduces no new security
new security considerations beyond those described in [RFC3611]. considerations beyond those described in [RFC3611]. This block does
This block does not provide per-packet statistics so the risk to not provide per-packet statistics, so the risk to confidentiality
confidentiality documented in Section 7, paragraph 3 of [RFC3611] documented in Section 7, paragraph 3 of [RFC3611] does not apply.
does not apply.
8. Contributors 8. Contributors
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, Claire Bi, Bob Biskner, Benoit
Claus Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert Higashi, Claise, Kevin Connor, Claus Dahm, Spencer Dawkins, Randy Ethier, Roni
Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith Lantz, Even, Jim Frauenthal, Kevin Gross, Albert Higashi, Tom Hock, Shane
Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, Ravi Holthaus, Paul Jones, Rajesh Kumar, Keith Lantz, Mohamed Mostafa, Amy
Raviraj, Albrecht Schwarz, Tom Taylor, Hideaki Yamada,Claire Bi,Colin Pendleton, Colin Perkins, Mike Ramalho, Ravi Raviraj, Dan Romascanu,
Perkin, Dan Romascanu, Kevin Gross ,Glen Zorn, Spencer Dawkins and Albrecht Schwarz, Tom Taylor, Hideaki Yamada, and Glen Zorn.
Benoit Claise.
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", BCP 14, RFC 2119, March 1997.
[RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model [RFC3264] Rosenberg, J. and H. Schulzrinne, "An Offer/Answer Model
with the Session Description Protocol (SDP)", RFC 3264, with Session Description Protocol (SDP)", RFC 3264,
June 2002. June 2002.
[RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V.
Applications", RFC 3550, July 2003. 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 [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control
Protocol Extended Reports (RTCP XR)", November 2003. Protocol Extended Reports (RTCP XR)", RFC 3611,
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", RFC 4566, July 2006.
[RFC6776] Wu, Q., "Measurement Identity and information Reporting [RFC6776] Clark, A. and Q. Wu, "Measurement Identity and Information
using SDES item and XR Block", RFC 6776, August 2012. Reporting Using a Source Description (SDES) Item and an
RTCP Extended Report (XR) Block", RFC 6776, October 2012.
10.2. Informative References 10.2. Informative References
[QMB] Clark, A., "RTP Control Protocol (RTCP) Extended Report [QMB] Clark, A., "RTP Control Protocol (RTCP) Extended Report
(XR) Blocks for QoE Metric Reporting", (XR) Blocks for QoE Metric Reporting", Work in Progress,
ID draft-ietf-xrblock-rtcp-xr-qoe-08, May 2013. May 2013.
[RFC5481] Morton, A. and B. Claise, "Packet Delay Variation [RFC5481] Morton, A. and B. Claise, "Packet Delay Variation
Applicability Statement", RFC 5481, March 2009. Applicability Statement", RFC 5481, March 2009.
[RFC6390] Clark, A. and B. Claise, "Framework for Performance Metric [RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New
Development", RFC 6390, October 2011. Performance Metric Development", BCP 170, RFC 6390,
October 2011.
[RFC6709] Carpenter, B., Aboba, B., and S. Cheshire, "Design [RFC6709] Carpenter, B., Aboba, B., and S. Cheshire, "Design
Considerations for Protocol Extensions", RFC 6709, Considerations for Protocol Extensions", RFC 6709,
September 2012. September 2012.
[RFC6792] Hunt, G., Wu, Q., and P. Arden, "Monitoring Architectures [RFC6792] Wu, Q., Hunt, G., and P. Arden, "Guidelines for Use of the
for RTP", RFC 6792, November 2012. RTP Monitoring Framework", RFC 6792, November 2012.
Appendix A. Metrics represented using RFC6390 Template
RFC EDITOR NOTE: please change XXXX in [RFCXXXX] by the new RFC Appendix A. Metrics Represented Using the Template from RFC 6390
number, when assigned.
a. de-jitter buffer nominal delay Metric a. De-Jitter Buffer Nominal Delay Metric
* Metric Name: de-jitter buffer nominal delay in RTP * Metric Name: De-jitter buffer nominal delay in RTP
* Metric Description: The "expected arrival time" is the time * Metric Description: The "expected arrival time" is the time
that a RTP packet would arrive if there was no delay that an RTP packet would arrive if there was no delay
variation. The delay applied to packets that arrive at their variation. The delay applied to packets that arrive at their
expected time is known as the Nominal Delay. expected time is known as the Nominal Delay.
* Method of Measurement or Calculation: See section 4.2, de- * Method of Measurement or Calculation: See Section 4.2,
jitter buffer nominal delay definition [RFCXXXX]. de-jitter buffer nominal delay definition.
* Units of Measurement: See section 4.2, de-jitter buffer * Units of Measurement: See Section 4.2, de-jitter buffer
nominal delay definition [RFCXXXX]. nominal delay definition.
* Measurement Point(s) with Potential Measurement Domain: See * Measurement Point(s) with Potential Measurement Domain: See
section 4, 1st paragraph [RFCXXXX]. Section 4.
* Measurement Timing: See section 4, 1st paragraph [RFCXXXX] for * Measurement Timing: See Section 4 for measurement timing and
measurement timing and section 4.2 paragraph [RFCXXXX] for Section 4.2 for Interval Metric flag.
Interval Metric flag.
* Use and applications: See section 1.4 [RFCXXXX]. * Use and Applications: See Section 1.4.
* Reporting model: See RFC3611. * Reporting Model: See RFC 3611.
b. de-jitter buffer maximum delay Metric b. De-Jitter Buffer Maximum Delay Metric
* Metric Name: de-jitter buffer maximum delay in RTP * Metric Name: De-jitter buffer maximum delay in RTP.
* Metric Description: It is the current maximum de-jitter buffer * Metric Description: It is the current maximum de-jitter buffer
delay for RTP traffic which corresponds to the earliest delay for RTP traffic that corresponds to the earliest
arriving packet that would not be discarded. arriving packet that would not be discarded.
* Method of Measurement or Calculation: See section 4.2, de- * Method of Measurement or Calculation: See Section 4.2,
jitter buffer maximum delay definition and section 3, the last de-jitter buffer maximum delay definition and Section 3, the
paragraph [RFCXXXX]. last paragraph.
* Units of Measurement: See section 4.2, de-jitter buffer * Units of Measurement: See Section 4.2, de-jitter buffer
maximum delay definition [RFCXXXX]. maximum delay definition.
* Measurement Point(s) with Potential Measurement Domain: See * Measurement Point(s) with Potential Measurement Domain: See
section 4, 1st paragraph [RFCXXXX]. Section 4.
* Measurement Timing: See section 4, 1st paragraph [RFCXXXX] for * Measurement Timing: See Section 4 for measurement timing and
measurement timing and section 4.2 paragraph [RFCXXXX] for Section 4.2 for Interval Metric flag.
Interval Metric flag.
* Use and applications: See section 1.4 [RFCXXXX]. * Use and Applications: See Section 1.4.
* Reporting model: See RFC3611. * Reporting Model: See RFC 3611.
c. de-jitter buffer high water mark Metric c. De-Jitter Buffer High-Water Mark Metric
* Metric Name: de-jitter buffer high water mark in RTP * Metric Name: De-jitter buffer high-water mark in RTP.
* Metric Description: It is the highest value of the de-jitter * Metric Description: It is the highest value of the de-jitter
buffer nominal delay for RTP traffic which occurred at any buffer nominal delay for RTP traffic which occurred at any
time during the reporting interval. time during the reporting interval.
* Method of Measurement or Calculation: See section 4.2, de- * Method of Measurement or Calculation: See Section 4.2,
jitter buffer high water mark definition [RFCXXXX]. de-jitter buffer high-water mark definition.
* Units of Measurement: See section 4.2, de-jitter buffer * Units of Measurement: See Section 4.2, de-jitter buffer
nominal delay definition [RFCXXXX]. nominal delay definition.
* Measurement Point(s) with Potential Measurement Domain: See * Measurement Point(s) with Potential Measurement Domain: See
section 4, 1st paragraph [RFCXXXX]. Section 4.
* Measurement Timing: See section 4, 1st paragraph [RFCXXXX] for * Measurement Timing: See Section 4 for measurement timing and
measurement timing and section 4.2 paragraph [RFCXXXX] for Section 4.2 for Interval Metric flag.
Interval Metric flag.
* Use and applications: See section 1.4 [RFCXXXX]. * Use and Applications: See Section 1.4.
* Reporting model: See RFC3611. * Reporting Model: See RFC 3611.
d. de-jitter buffer low water mark Metric d. De-Jitter Buffer Low-Water Mark Metric
* Metric Name: de-jitter buffer low water mark in RTP * Metric Name: De-jitter buffer low-water mark in RTP.
* Metric Description: It is the lowest value of the de-jitter * Metric Description: It is the lowest value of the de-jitter
buffer nominal delay for RTP traffic which occurred at any buffer nominal delay (for RTP traffic) that occurred at any
time during the reporting interval. time during the reporting interval.
* Method of Measurement or Calculation: See section 4.2, de- * Method of Measurement or Calculation: See Section 4.2,
jitter buffer low water mark definition [RFCXXXX]. de-jitter buffer low-water mark definition.
* Units of Measurement: See section 4.2, de-jitter buffer low * Units of Measurement: See Section 4.2, de-jitter buffer low
water mark definition [RFCXXXX]. water mark definition.
* Measurement Point(s) with Potential Measurement Domain: See * Measurement Point(s) with Potential Measurement Domain: See
section 4, 1st paragraph [RFCXXXX]. Section 4, 1st paragraph.
* Measurement Timing: See section 4, 1st paragraph [RFCXXXX] for
measurement timing and section 4.2 paragraph [RFCXXXX] for
Interval Metric flag.
* Use and applications: See section 1.4 [RFCXXXX].
* Reporting model: See RFC3611.
Appendix B. Change Log
Note to the RFC-Editor: please remove this section prior to
publication as an RFC.
B.1. draft-ietf-xrblock-rtcp-xr-jb-12
The following are the major changes to previous version :
o Editorial changes based on recieved comments.
B.2. draft-ietf-xrblock-rtcp-xr-jb-11
The following are the major changes to previous version :
o Comments in WGLC and from PM-DIR review are addressed in this
version.
B.3. draft-ietf-xrblock-rtcp-xr-jb-10
The following are the major changes to previous version :
o Add some text to section 3.2 to clarify how fixed de-jitter buffer
is used.
o Other Editorial changes.
B.4. draft-ietf-xrblock-rtcp-xr-jb-09
The following are the major changes to previous version :
o Incorporate proposed changes by Kevin and proposed text by Alan to
address interoperability report issue.
o Add new appendix to format metrics using RFC6390 template.
B.5. draft-ietf-xrblock-rtcp-xr-jb-08
The following are the major changes to previous version :
o Rewrote descriptive text and definitions for clarification.
B.6. draft-ietf-xrblock-rtcp-xr-jb-07
The following are the major changes to previous version :
o Add one new section to discuss de-jitter buffer operation.
B.7. draft-ietf-xrblock-rtcp-xr-jb-05
The following are the major changes to previous version :
o Some editorial change changes based on the discussion with Glen
and Kevin on the list.
B.8. draft-ietf-xrblock-rtcp-xr-jb-03
The following are the major changes to previous version :
o Reduce the "jb cfg" to 1-bit based on discussion in the WGLC.
o Other editorial change changes aligning with PDV,Delay draft.
B.9. draft-ietf-xrblock-rtcp-xr-jb-02
The following are the major changes to previous version :
o Add some explanation text in the SDP offer/answer section.
o Add some text in applicability section to explain the use to
report de-jitter buffer metrics.
o Other editorial change changes aligning with PDV,Delay draft.
B.10. draft-ietf-xrblock-rtcp-xr-jb-01
The following are the major changes to previous version :
o Outdated reference update
o Add one Editor notes to ask clarification on the use of reporting
de-jitter buffer metrics.
o Other Editorial changes.
B.11. draft-ietf-xrblock-rtcp-xr-jb-00
The following are the major changes to previous version :
o Boilerplate updates. * Measurement Timing: See Section 4 for measurement timing and
Section 4.2 for Interval Metric flag.
o references updates * Use and Applications: See Section 1.4.
o allocate 32 bit field in report block for SSRC * Reporting Model: See RFC 3611.
o Other editorial changes to get alignment with MONARCH draft.
Authors' Addresses Authors' Addresses
Alan Clark Alan Clark
Telchemy Incorporated Telchemy Incorporated
2905 Premiere Parkway, Suite 280 2905 Premiere Parkway, Suite 280
Duluth, GA 30097 Duluth, GA 30097
USA USA
Email: alan.d.clark@telchemy.com EMail: alan.d.clark@telchemy.com
Varun Singh Varun Singh
Aalto University Aalto University
School of Electrical Engineering School of Electrical Engineering
Otakaari 5 A Otakaari 5 A
Espoo, FIN 02150 Espoo, FIN 02150
Finland Finland
Email: varun@comnet.tkk.fi EMail: varun@comnet.tkk.fi
Qin Wu Qin Wu
Huawei Huawei
101 Software Avenue, Yuhua District 101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012 Nanjing, Jiangsu 210012
China China
Email: sunseawq@huawei.com EMail: sunseawq@huawei.com
 End of changes. 117 change blocks. 
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