Audio/Video Transport Working Group G. Hunt
Internet-Draft Unaffiliated
Intended status: Standards Track A. Clark
Expires: April 15, 2012 Telchemy
Q. Wu
Huawei
October 13, 2011
Measurement Identity and information Reporting using SDES item and XR
Block
draft-ietf-xrblock-rtcp-xr-meas-identity-01.txt
Abstract
This document defines a RTCP SDES item and a RTCP XR Block carrying
parameters which identify a measurement, 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.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 15, 2012.
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
Hunt, et al. Expires April 15, 2012 [Page 1]
Internet-Draft Measurement Reporting October 2011
the Trust Legal Provisions and are provided without warranty as
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 . . . . . . . . . . . . . . . . . . . . . 9
5.1. New RTCP SDES Type value . . . . . . . . . . . . . . . . . 9
5.2. New RTCP XR Block Type value . . . . . . . . . . . . . . . 9
5.3. Contact information for registrations . . . . . . . . . . 9
6. Security Considerations . . . . . . . . . . . . . . . . . . . 10
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.1. Normative References . . . . . . . . . . . . . . . . . . . 11
7.2. Informative References . . . . . . . . . . . . . . . . . . 11
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 12
A.1. draft-ietf-xrblock-xr-rtcp-meas-identity-00 . . . . . . . 12
A.2. draft-ietf-xrblock-xr-rtcp-meas-identity-01 . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13
Hunt, et al. Expires April 15, 2012 [Page 2]
Internet-Draft Measurement Reporting October 2011
1. Introduction
This draft defines one new RTCP SDES item and one new XR Report Block
to carry parameters which identify a measurement for use in a range
of RTP applications. The SDES item and the XR Report Block do not
itself contain any measurement results (metrics).However, they
provide information relevant to a measurement reported in one or more
other block types, including
o a field for incorporation of an application-specific auxiliary
identifier,
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 [RFC3550].
The RTCP SDES item containing the measurement identity is intended to
provide information to relate RTP to a non-RTP session while 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.
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 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
example blocks which were defined before the Measurement Identity and
information mechanism was introduced by this document.
Hunt, et al. Expires April 15, 2012 [Page 3]
Internet-Draft Measurement Reporting October 2011
1.1. RTCP and RTCP XR Reports
The use of RTCP for reporting is defined in [RFC3550]. [RFC3611]
defined an extensible structure for reporting using an RTCP Extended
Report (XR). This draft defines a new Extended Report block that
MUST be used as defined in [RFC3550] and [RFC3611].
1.2. Performance Metrics Framework
The Performance Metrics Framework [PMOLFRAME] provides guidance on
the definition and specification of performance metrics. The RTP
Monitoring Architectures[MONARCH] provides guideline for reporting
block format using RTCP XR . Metrics or SDES item described in this
draft either reference external definitions or define metrics
generally in accordance with [PMOLFRAME][MONARCH].
1.3. Applicability
The RTCP SDES item and the RTCP XR block defined in this document
provides information relevant to the measurement 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 in the same RTCP packet as
the SDES item contain measurement identity.
Hunt, et al. Expires April 15, 2012 [Page 4]
Internet-Draft Measurement Reporting October 2011
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]
Hunt, et al. Expires April 15, 2012 [Page 5]
Internet-Draft Measurement Reporting October 2011
3. Measurement Identity SDES Item
This section defines the format of 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 has a fixed-length field for version, source count, packet
type (PT), length as well as a variable-length field for the SDES
item. 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]. Where the identifier is less than 32
bits, the identifier SHOULD be mapped into the most significant bits
of the field. If no additional identifier is provided, all bits of
the field MUST be set to zero. This item MUST be ignored by
applications which are not configured to make use of it.
Hunt, et al. Expires April 15, 2012 [Page 6]
Internet-Draft Measurement Reporting October 2011
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 | Rsv. | block length = 6 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of stream source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| reserved | first seq num |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| extended first sequence number of interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| extended last sequence number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Duration (Cumulative) (ms) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Measurement Duration (Interval) (ms) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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.]
Rsv.: 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.
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.
Hunt, et al. Expires April 15, 2012 [Page 7]
Internet-Draft Measurement Reporting October 2011
SSRC of source: 32 bits
As defined in Section 4.1 of [RFC3611].
Reserved: 16 bits
These bits are reserved. They MUST be ignored by receivers. They
MUST be set to zero by senders.
First seq num: 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.
Extended last sequence number: 32 bits
The extended RTP sequence number of the last received RTP packet
which contributed to this measurement.
Measurement Duration (Cumulative) (ms): 32 bits
The duration in ms of the reporting interval applicable to
Cumulative reports which use this Measurement Information block.
Measurement Duration (Interval) (ms): 32 bits
The duration in ms of the reporting interval applicable to
Interval reports which use this Measurement Information block.
Hunt, et al. Expires April 15, 2012 [Page 8]
Internet-Draft Measurement Reporting October 2011
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 additional five SDES types 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
Hunt, et al. Expires April 15, 2012 [Page 9]
Internet-Draft Measurement Reporting October 2011
6. Security Considerations
RTCP reports can contain sensitive information since they can provide
information about the nature and duration of a session established
between two or more endpoints.Therefore, the use of security
mechanisms with RTP documented in Section 9 of [RFC3550] should
apply.
Hunt, et al. Expires April 15, 2012 [Page 10]
Internet-Draft Measurement Reporting October 2011
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.
7.2. Informative References
[MONARCH] Wu, Q., "Monitoring Architectures for RTP",
ID draft-ietf-avtcore-monarch-04, August 2011.
[MPEG2] "ISO/IEC, "Standard 13818-1"", December 2000.
[PMOLFRAME]
Clark, A. and B. Claise, "Framework for Performance Metric
Development", ID draft-ietf-pmol-metrics-framework-12,
July 2011.
Hunt, et al. Expires April 15, 2012 [Page 11]
Internet-Draft Measurement Reporting October 2011
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-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.
A.2. 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.
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.
Hunt, et al. Expires April 15, 2012 [Page 12]
Internet-Draft Measurement Reporting October 2011
Authors' Addresses
Geoff Hunt
Unaffiliated
Email: r.geoff.hunt@gmail.com
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
Hunt, et al. Expires April 15, 2012 [Page 13]
