Internet DRAFT - draft-ietf-xrblock-rtcp-xr-meas-identity
draft-ietf-xrblock-rtcp-xr-meas-identity
Audio/Video Transport Working Group A. Clark
Internet-Draft Telchemy
Intended status: Standards Track Q. Wu
Expires: March 3, 2013 Huawei
August 30, 2012
Measurement Identity and information Reporting using SDES item and XR
Block
draft-ietf-xrblock-rtcp-xr-meas-identity-10.txt
Abstract
This document defines an RTP Control Protocol (RTCP) Source
Description (SDES) item and an RTCP Extended Report (XR) Block
carrying parameters that identify and describe a measurement period,
to which one or more other RTCP XR Report Blocks may refer.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on March 3, 2013.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . . 4
1.2. Performance Metrics Framework . . . . . . . . . . . . . . 4
1.3. Applicability . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 5
3. Measurement Identity SDES Item . . . . . . . . . . . . . . . . 6
3.1. APSI: Application Specific Identifier SDES Item . . . . . 6
4. Measurement Information XR Block . . . . . . . . . . . . . . . 7
4.1. Report Block Structure . . . . . . . . . . . . . . . . . . 7
4.2. Definition of Fields in Measurement Information Report
Block . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
5.1. New RTCP SDES Type value . . . . . . . . . . . . . . . . . 10
5.2. New RTCP XR Block Type value . . . . . . . . . . . . . . . 10
5.3. Contact information for registrations . . . . . . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 11
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.1. Normative References . . . . . . . . . . . . . . . . . . . 12
7.2. Informative References . . . . . . . . . . . . . . . . . . 12
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 13
A.1. draft-ietf-xrblock-xr-rtcp-meas-identity-10 . . . . . . . 13
A.2. draft-ietf-xrblock-xr-rtcp-meas-identity-09 . . . . . . . 13
A.3. draft-ietf-xrblock-xr-rtcp-meas-identity-08 . . . . . . . 13
A.4. draft-ietf-xrblock-xr-rtcp-meas-identity-07 . . . . . . . 13
A.5. draft-ietf-xrblock-xr-rtcp-meas-identity-06 . . . . . . . 13
A.6. draft-ietf-xrblock-xr-rtcp-meas-identity-05 . . . . . . . 14
A.7. draft-ietf-xrblock-xr-rtcp-meas-identity-04 . . . . . . . 14
A.8. draft-ietf-xrblock-xr-rtcp-meas-identity-03 . . . . . . . 14
A.9. draft-ietf-xrblock-xr-rtcp-meas-identity-02 . . . . . . . 14
A.10. draft-ietf-xrblock-xr-rtcp-meas-identity-01 . . . . . . . 14
A.11. draft-ietf-xrblock-xr-rtcp-meas-identity-00 . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
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1. Introduction
This document defines one new RTP Control Protocol (RTCP) Source
Description (SDES) [RFC3550] item, and one new Extended Report (XR)
Report Block carrying parameters that identify and describe a
measurement period, to which one or more other RTCP XR Report Blocks
may refer.
The SDES item provides a field for an application specific auxiliary
identifier. This identifier may be used to correlate data in XR
Blocks within an RTP session with data from a non-RTP session.
A RTCP Measurement Identity SDES packet may be associated with a set
of RTCP XR metrics blocks which share the same application specific
measurement identifier.
The XR Report Block does not contain any measurement results
(metrics). Instead, it provides information relevant to a
measurement reported in one or more other block types, including:
o the sequence number of the first packet of the RTP session,
o the extended sequence numbers of the first packet of the current
measurement interval, and the last packet included in the
measurement,
o the duration of the most recent measurement interval and
o the duration of the interval applicable to cumulative measurements
(which may be the duration of the RTP session to date).
The method for calculation of the extended RTP sequence number is
provide in Real-time Transport Protocol (RTP) [RFC3550].
The RTCP XR Report Block containing the measurement information is
intended to provide a single copy of the information necessary to
relate measurement data in the RTCP XR blocks to the stream, and
measurement period, to which they refer. Commonly, multiple other
small metric blocks contain measurement data for the same stream and
period, and it would be a large overhead if all of these metric
blocks carried duplicated data for measurement identification.
The RTCP XR Report Block may be associated with a set of RTCP XR
metrics blocks which share the same information relevant to a
reported measurement. There may be several such sets in an RTCP
packet, in which each set share the same information relevant to a
reported measurement. There may also be RTCP XR blocks in the packet
which are not associated with a Measurement Information block, for
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example blocks which were defined before the Measurement Identity and
information mechanism was introduced by this document.
1.1. RTCP and RTCP XR Reports
The use of RTCP for reporting is defined in [RFC3550]. [RFC3611]
defines an extensible structure for reporting using an RTCP Extended
Report (XR). This document defines a new Extended Report block. The
use of Extended Report blocks is defined by [RFC3611].
1.2. Performance Metrics Framework
The Performance Metrics Framework [RFC6390] provides guidance on the
definition and specification of performance metrics. The RTP
Monitoring Architectures[MONARCH] provides guideline for reporting
block format using RTCP XR. The SDES item and XR Block described in
this document are in accordance with [RFC6390] and [MONARCH].
1.3. Applicability
The RTCP SDES item and the RTCP XR block defined in this document
provides information relevant to the measurements for members of a
family of RTCP XR metrics blocks which are designed to use it. To
use the mechanism defined here, the RTCP XR block containing
measurement information is not required to be in the same RTCP packet
as the SDES item containing measurement identity.
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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].
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3. Measurement Identity SDES Item
This section defines the format of the Measurement Identity SDES
item. The SDES item is carried in the RTCP SDES packet. The packet
format for the RTCP SDES is defined in Section 6.5 of [RFC3550].
Each SDES packet is composed of a header with fixed-length fields for
version, source count, packet type (PT), and length, followed by zero
of more SDES items. In the SDES packet, the PT field is set to SDES
(202).
3.1. APSI: Application Specific Identifier SDES Item
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| APSI=TBD | length |application specific identifier
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ....
+-+-+-+-+-+-+-+-+
Application specific identifier is an additional identifier which is
useful in the context of a specific application, e.g. an MPEG-2
transport identifier [MPEG2]. This item MUST be ignored by
applications that are not configured to make use of it. The
identifier is variable length. Its length is described by the length
field. The value of the length field does not include the two octet
SDES item header.
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4. Measurement Information XR Block
4.1. Report Block Structure
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BT=NMI | Reserved | block length = 7 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of stream source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | first sequence number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| extended first sequence number of interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| extended last sequence number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Duration (Interval) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Duration (Cumulative) - Seconds (bit 0-31) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Duration (Cumulative) - Fraction (bit 0-31) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Report Block Structure
4.2. Definition of Fields in Measurement Information Report Block
Block type (BT): 8 bits
A Measurement Information Report Block is identified by the
constant NMI.
[Note to RFC Editor: please replace NMI with the IANA provided
RTCP XR block type for this block.]
Reserved.: 8 bits
These bits are reserved. They MUST be set to zero by senders and
ignored by receivers.
Block Length: 16 bits
The length of this report block in 32-bit words minus one. For
the Measurement Information block, the block length is equal to 7.
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SSRC of source: 32 bits
As defined in Section 4.1 of [RFC3611].
Reserved: 16 bits
These bits are reserved. They MUST be set to zero by senders and
ignored by receivers.
First sequence number: 16 bits
The RTP sequence number of the first received RTP packet of the
session, used to determine the number of packets contributing to
cumulative measurements.
Extended first sequence number of interval: 32 bits
The extended RTP sequence number of the first received RTP packet
of the current measurement interval. The extended sequence number
is expressed as the low 16 bits value containing the sequence
number received in an RTP data packet and the most significant 16
bits value containing the corresponding count of sequence number
cycles. For additional information on extended sequence numbers
see "extended highest sequence number received" definition in RFC
3550 section 6.4.1 and RFC 3550 Appendix A.1.
Extended last sequence number: 32 bits
The extended RTP sequence number of the last received RTP packet
which contributed to this measurement. The extended sequence
number is expressed as the low 16 bits value containing the
sequence number received in an RTP data packet and the most
significant 16 bits value containing the corresponding count of
sequence number cycles. For additional information on extended
sequence numbers see "extended highest sequence number received"
definition in RFC 3550 section 6.4.1 and RFC 3550 Appendix A.1.
Measurement Duration (Interval): 32 bits
The duration, expressed in units of 1/65536 seconds, of the
reporting interval applicable to Interval reports which use this
Measurement Information block . The value of this field can be
calculated by the receiver of the RTP media stream, for example,
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based on received RTP media packets or using RTCP method described
in [RFC3550].
Measurement Duration (Cumulative): 64 bits
The duration of the reporting interval applicable to Cumulative
reports which use this Measurement Information block. The value
of this field is represented using a 64-bit NTP-format timestamp
as defined in [RFC5905], which is 64-bit unsigned fixed-point
number with the integer part in the first 32 bits and the
fractional part in the last 32 bits. It can be calculated by the
receiver of the RTP media stream, for example, based on received
RTP media packets or using RTCP method described in [RFC3550].
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5. IANA Considerations
New SDES types for RTCP SDES are subject to IANA registration. For
general guidelines on IANA considerations for RTCP SDES, refer to
[RFC3550].
5.1. New RTCP SDES Type value
This document assigns one additional SDES type in the IANA "RTCP XR
Block Type Registry" to the Measurement Identity SDES items as
follow:
abbrev. name value
APSI: Application Specific Identifier TBD
[Note to RFC Editor: please replace APSI with the IANA provided RTCP
SDES type for the SDES item.]
5.2. New RTCP XR Block Type value
This document assigns the block type value NMI in the IANA "RTCP XR
Block Type Registry" to the "Measurement Information Block".
[Note to RFC Editor: please replace NMI with the IANA provided RTCP
XR block type for this block.]
5.3. Contact information for registrations
The contact information for the registrations is:
Qin Wu (sunseawq@huawei.com)
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
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6. Security Considerations
RTCP reports can contain sensitive information, including information
about the nature and duration of a session established between two or
more endpoints. Therefore, the use of security mechanisms with RTP,
as documented in Section 9 of [RFC3550] applies.
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7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", March 1997.
[RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time
Applications", RFC 3550, July 2003.
[RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control
Protocol Extended Reports (RTCP XR)", November 2003.
[RFC5905] Mills, D., Matin, J., Ed., Burbank, J., and W. Kasch,
"Network Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, June 2010.
7.2. Informative References
[MONARCH] Wu, Q., Hunt, G., and P. , "Monitoring Architectures for
RTP", ID draft-ietf-avtcore-monarch-17, June 2012.
[MPEG2] "ISO/IEC, "Standard 13818-1"", December 2000.
[RFC6390] Clark, A. and B. Claise, "Framework for Performance Metric
Development", RFC 6390, October 2011.
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Appendix A. Change Log
Note to the RFC-Editor: please remove this section prior to
publication as an RFC.
A.1. draft-ietf-xrblock-xr-rtcp-meas-identity-10
The following are the major changes to
draft-ietf-xrblock-xr-rtcp-meas-identity-09:
o Move Geoff Hunt from author list to Contributors section based on
his suggestion.
A.2. draft-ietf-xrblock-xr-rtcp-meas-identity-09
The following are the major changes to
draft-ietf-xrblock-xr-rtcp-meas-identity-08:
o Change header from "Measurement Reporting" to "Measurement
Identity and Duration".
A.3. draft-ietf-xrblock-xr-rtcp-meas-identity-08
The following are the major changes to
draft-ietf-xrblock-xr-rtcp-meas-identity-07:
o Expand 32-bit measurement interval (cumulative) into 64 bits and
use NTP timestamp format.
o Delete the last sentence in the sub-section 3.1.
o Block length change for consistency.
o Other editorial changes.
A.4. draft-ietf-xrblock-xr-rtcp-meas-identity-07
The following are the major changes to
draft-ietf-xrblock-xr-rtcp-meas-identity-06:
o One more Editorial change.
A.5. draft-ietf-xrblock-xr-rtcp-meas-identity-06
The following are the major changes to
draft-ietf-xrblock-xr-rtcp-meas-identity-05:
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o Editorial changes.
A.6. draft-ietf-xrblock-xr-rtcp-meas-identity-05
The following are the major changes to
draft-ietf-xrblock-xr-rtcp-meas-identity-04:
o Clarify the definition of extended sequence number.
A.7. draft-ietf-xrblock-xr-rtcp-meas-identity-04
The following are the major changes to
draft-ietf-xrblock-xr-rtcp-meas-identity-03:
o Change unit of measurement duration from ms to 1/65536 seconds.
A.8. draft-ietf-xrblock-xr-rtcp-meas-identity-03
The following are the major changes to
draft-ietf-xrblock-xr-rtcp-meas-identity-02:
o The Editorial changes.
A.9. draft-ietf-xrblock-xr-rtcp-meas-identity-02
The following are the major changes to
draft-ietf-xrblock-xr-rtcp-meas-identity-01:
o Relocating information that belong to SDES item and XR Block
respectively in the section 1.
o Rephrasing the text that describes SDES packet composition.
o Rephrasing identifier description.
o Other Editorial changes.
A.10. draft-ietf-xrblock-xr-rtcp-meas-identity-01
The following are the major changes to
draft-ietf-xrblock-xr-rtcp-meas-identity-00:
o Replace SDES item containing additional measurement information
with XR Block.
o Add section 2 to describe following RFC2119 language.
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o Add Section 1.2 to make SDES item and XR Report be compliant with
RFC3550 and RFC3611
o Add Section 1.3 to make SDES item and XR Report follow Performance
Metrics Framework and RTP Monitoring Architecture.
o Add section5.2 to register the new RTCP XR Block Type value.
o Remove RTCP SDES Type values that are needed.
A.11. draft-ietf-xrblock-xr-rtcp-meas-identity-00
The following are the major changes to
draft-ietf-avt-rtcp-xr-meas-identity-02:
o Change the use of SDES item to convey measurement identity instead
of XR Block in section 2.
o Update references.
o Update security section and remove SDP signaling section.
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Authors' Addresses
Alan Clark
Telchemy Incorporated
2905 Premiere Parkway, Suite 280
Duluth, GA 30097
USA
Email: alan.d.clark@telchemy.com
Qin Wu
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: sunseawq@huawei.com
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