Audio/Video Transport Working Group Q. Wu, Ed.
Internet-Draft Huawei
Intended status: Informational G. Hunt
Expires: November 28, 2011 Unaffiliated
P. Arden
BT
May 27, 2011
Monitoring Architectures for RTP
draft-ietf-avtcore-monarch-02.txt
Abstract
This memo proposes an architecture for extending RTCP with a new RTCP
XR (RFC3611) block type to report new metrics regarding media
transmission or reception quality, as proposed in RFC5968. This memo
suggests that a new block should contain a single metric or a small
number of metrics relevant to a single parameter of interest or
concern, rather than containing a number of metrics which attempt to
provide full coverage of all those parameters of concern to a
specific application. Applications may then "mix and match" to
create a set of blocks which covers their set of concerns. Where
possible, a specific block should be designed to be re-usable across
more than one application, for example, for all of voice, streaming
audio and video.
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 November 28, 2011.
Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved.
Wu, et al. Expires November 28, 2011 [Page 1]
Internet-Draft RTP Monitoring Architectures May 2011
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
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements notation . . . . . . . . . . . . . . . . . . . . 4
3. RTP monitoring architecture . . . . . . . . . . . . . . . . . 5
3.1. RTCP Metric Block Report and associated parameters . . . . 7
4. Issues with reporting metric block using RTCP XR extension . . 9
5. Guideline for reporting block format using RTCP XR . . . . . . 10
5.1. Using small blocks . . . . . . . . . . . . . . . . . . . . 10
5.2. Sharing the identity information . . . . . . . . . . . . . 10
5.3. Correlating identity information with the data . . . . . . 12
6. An example of a metric block . . . . . . . . . . . . . . . . . 13
7. Application to RFC 5117 topologies . . . . . . . . . . . . . . 14
7.1. Applicability to MCU . . . . . . . . . . . . . . . . . . . 14
7.2. Applicability to Translators . . . . . . . . . . . . . . . 14
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
9. Security Considerations . . . . . . . . . . . . . . . . . . . 17
10. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 18
11. Informative References . . . . . . . . . . . . . . . . . . . . 19
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 20
A.1. draft-ietf-avtcore-monarch-00 . . . . . . . . . . . . . . 20
A.2. draft-ietf-avtcore-monarch-01 . . . . . . . . . . . . . . 20
A.3. draft-ietf-avtcore-monarch-02 . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22
Wu, et al. Expires November 28, 2011 [Page 2]
Internet-Draft RTP Monitoring Architectures May 2011
1. Introduction
As more users and subscribers rely on real time application services,
uncertainties in the performance and availability of these services
are driving the need to support new standard methods for gathering
performance metrics from RTP applications. These rapidly emerging
standards, such as RTCP XR [RFC3611]and other RTCP extension to
Sender Reports(SR), Receiver Reports (RR) [RFC3550]are being
developed for the purpose of collecting and reporting performance
metrics from endpoint devices that can be used to correlate the
metrics, provide end to end service visibility and measure and
monitor QoE.
However the proliferation of RTP/RTCP specific metrics for transport
and application quality monitoring has been identified as a potential
problem for RTP/RTCP interoperability, which attempt to provide full
coverage of all those parameters of concern to a specific
application. Since different applications layered on RTP may have
some monitoring requirements in common, therefore these metrics
should be satisfied by a common design.
The objective of this document is to define an extensible RTP
monitoring framework to provide a small number of re-usable QoS/QoE
metrics which facilitate reduced implementation costs and help
maximize inter-operability. [RFC5968] has stated that, where RTCP is
to be extended with a new metric, the preferred mechanism is by the
addition of a new RTCP XR [RFC3611] block. This memo assumes that
any requirement for a new metric to be transported in RTCP will use a
new RTCP XR block.
Wu, et al. Expires November 28, 2011 [Page 3]
Internet-Draft RTP Monitoring Architectures May 2011
2. Requirements notation
This memo is informative and as such contains no normative
requirements.
In addition, the following terms are defined:
Transport level metrics
A set of metrics which characterise the three transport
impairments of packet loss, packet delay, and packet delay
variation. These metrics should be usable by any application
which uses RTP transport.
Application level metrics
Metrics relating to QoE related parameters. These metrics are
measured at the application level and focus on quality of content
rather than network parameters.
End System metrics
Metrics relating to the way a terminal deals with transport
impairments affecting the incident RTP stream. These may include
de-jitter buffering, packet loss concealment, and the use of
redundant streams (if any) for correction of error or loss.
Wu, et al. Expires November 28, 2011 [Page 4]
Internet-Draft RTP Monitoring Architectures May 2011
3. RTP monitoring architecture
The RTP monitoring architecture comprises the following two key
functional components shown below:
o Monitor
o Metric Block Structure
Monitor is a functional component defined in RFC3550 that acts as a
source of information gathered for monitoring purposes. It may also
collect statistics from multiple source, stores such information
reported by RTCP XR or other RTCP extension appropriately as base
metric or calculates composite metric. According to the definition
of monitor in RFC3550, the end system that source RTP streams, an
intermediate-system that forwards RTP packets to End-devices or a
third party that does not participate RTP session (i.e., the third
party monitor depicted in figure 1) can be envisioned to act as
Monitor within the RTP monitoring architecture.
The Metric Block exposes real time Application Quality information in
the appropriate report block format to monitor within the RTP
monitoring architecture. Both the RTCP or RTCP XR can be extended to
convey such information. The details on transport protocol for
metric block is described in Section 3.1.
Wu, et al. Expires November 28, 2011 [Page 5]
Internet-Draft RTP Monitoring Architectures May 2011
|---------------+
| Management |
+-------------------+ | System |
| RTP Sender | | +----------+ |
| +-----------+ | | | | |
---------------->| Monitor |---------5------->| Monitor | |
| | | | | | | | |
| | +-----------+ | | +----\-----+ |
| |+-----------------+| | | |
| ||Application || --------|-------+
| ||-Streaming video || |
| |---------|-VOIP || 5
| | ||-Video conference|| |
| | ||-Telepresence || +---------------+
| | ||-Ad insertion || | Third Party |
5 | |+-----------------+| | Monitor |
| | +-------------------+ +---------------+
| 1
| | +Intermediate------------+ |-------------- ---- ----+
| | | RTP System Report Block | RTP Receiver >--4-| |
| | | +---------- transported over| +-----------+ | |
| | | | RTCP extension | | Monitor |<-- |
|------------- Monitor |<--------5------|----| |<------|
| | | | Report Block +----/------+ ||
| | +----------+ transported over | ||
| | RTCP XR | |2 ||
| | +-----------------+ | | +-------/---------+ ||
| | |Application | | | |Application | ||
| | |-Streaming video | | | |-Streaming video | ||
| | |-VOIP | | 1 | |-VOIP | 3|
---->-Video conference|--------------->|-Video conference ||
| |-Telepresence | | | |-Telepresence | ||
| |-Ad insertion | | | |-Ad insertion | ||
| +-----------------+ | | +-----------------+ ||
| +-----------------+ | | +-----------------+ ||
| |Transport | | | |Transport | ||
| |-IP/UDP/RTP | | | |-IP/UDP/RTP >---||
| |-IP/TCP/RTP | | | | -IP/TCP/RTP | |
| |-IP/TCP/RTSP/RTP | | | |-IP/TCP/RTSP/RTP | |
| +-----------------+ | | +-----------------+ |
+------------------------+ +------------------------+
Figure 1: RTP Monitoring Architecture
1. RTP communication between real time applications
Wu, et al. Expires November 28, 2011 [Page 6]
Internet-Draft RTP Monitoring Architectures May 2011
2. Application level metrics
3. Transport level metrics
4. End System metrics
5. Reporting Session- metrics transmitted over specified interfaces
3.1. RTCP Metric Block Report and associated parameters
The basic RTCP Reception Report (RR) conveys reception statistics in
metric block report format for multiple RTP media streams including
o transport level statistics
o the fraction of packet lost since the last report
o the cumulative number of packets lost
o the highest sequence number received
o an estimate of the inter-arrival jitter
o and information to allow senders to calculate the network round
trip time.
The RTCP XRs [RFC3611] supplement the existing RTCP packets and
provide more detailed feedback on reception quality in several
categories:
o Loss and duplicate RLE reports
o Packet-receipt times reports
o Round-trip time reports
o Statistics Summary Reports
There are also various other scenarios in which it is desirable to
send RTCP Metric reports more frequently. The Audio/Video Profile
with Feedback [RFC4585]extends the standard A/V Profile[RFC3551] to
allow RTCP reports to be sent early provided RTCP bandwidth
allocation is respected. There are four use cases but are not
limited to:
o RTCP NACK is used to provide feedback on the RTP sequence number
of the lost packets.
Wu, et al. Expires November 28, 2011 [Page 7]
Internet-Draft RTP Monitoring Architectures May 2011
o RTCP XR is extended to provide feedback on multicast acquisition
statistics information and parameters.
o RTCP is extended to convey requests for full intra-coded frames or
select the reference picture, and signalchanges in the desired
temporal/spatial trade-off and maximum media bit rate.
o RTCP or RTCP XR is extended to provide feedback on ECN statistics
information.
Wu, et al. Expires November 28, 2011 [Page 8]
Internet-Draft RTP Monitoring Architectures May 2011
4. Issues with reporting metric block using RTCP XR extension
Issues that have come up in the past with reporting metric block
using RTCP XR extensions include (but are probably not limited to)
the following:
o Using large block. A single report block or metric is designed to
contain a large number of parameters in different classes for a
specific application. For example, RFC 3611 [RFC3611] defines
seven report block formats for network management and quality
monitoring. However some of these block types defined in
[RFC3611] are only specifically designed for conveying multicast
inference of network characteristics(MINC) or voice over IP (VoIP)
monitoring. However different applications layered on RTP may
have some monitoring requirements in common, design large block
only for specific applications may increase implementation cost
and minimize interoperability.
o Identity Information duplication. There may be situations where
an RTCP XR packet containing more than two metrics blocks, reports
on the same streams from the same source. In such case, each
metric block should have the same measurement identity, if each
metric block carry such duplicated data for the measurement,it
leads to redundant information in this design since equivalent
information is provided multiple times, once in *every*
identification packet. Though this ensures immunity to packet
loss, the design bring more complexity and the overhead is not
completely trivial.
o Metric Blocks association. There may be situations where an RTCP
XR packet containing four metrics blocks, reports on streams from
two sources. In such case, two identity blocks need to be added
into the RTCP XR packet to correlate two sources if identity
information is allowed separate from each metric block as one
independent block. However how to associate identity block with
relevant metric block data or other identity data is a problem,
e.g., all identity blocks are following all the metric block or
vice versa make one receiving RTCP XR packet hard to distinguish
from which metric block belong to which source.
Wu, et al. Expires November 28, 2011 [Page 9]
Internet-Draft RTP Monitoring Architectures May 2011
5. Guideline for reporting block format using RTCP XR
5.1. Using small blocks
Different applications using RTP for media transport certainly have
differing requirements for metrics transported in RTCP to support
their operation. For many applications, the basic metrics for
transport impairments provided in RTCP SR and RR packets [RFC3550]
(together with source identification provided in RTCP SDES packets)
are sufficient. For other applications additional metrics may be
required or at least sufficiently useful to justify the overheads,
both of processing in endpoints and of increased session bandwidth.
For example an IPTV application using Forward Error Correction (FEC)
might use either a metric of post-repair loss or a metric giving
detailed information about pre-repair loss bursts to optimise payload
bandwidth and the strength of FEC required for changing network
conditions. However there are many metrics available. It is likely
that different applications or classes of applications will wish to
use different metrics. Any one application is likely to require
metrics for more than one parameter but if this is the case,
different applications will almost certainly require different
combinations of metrics. If larger blocks are defined containing
multiple metrics to address the needs of each application, it becomes
likely that many different such larger blocks are defined, which
becomes a danger to interoperability.
To avoid this pitfall, this memo proposes the use of small RTCP XR
metrics blocks each containing a very small number of individual
metrics characterizing only one parameter of interest to an
application running over RTP. For example, at the RTP transport
layer, the parameter of interest might be packet delay variation, and
specifically the metric "IPDV" defined by [Y1540]. See Section 6 for
architectural considerations for a metrics block, using as an example
a metrics block to report packet delay variation.
5.2. Sharing the identity information
Any measurement must be identified. However if metrics are delivered
in small blocks there is a danger of inefficiency arising from
repeating this information in a number of metrics blocks within the
same RTCP packet, in cases where the same identification information
applies to multiple metrics blocks.
An instance of a metric must be identified using information which is
likely to include most of the following:
Wu, et al. Expires November 28, 2011 [Page 10]
Internet-Draft RTP Monitoring Architectures May 2011
o the node at which it was measured,
o the source of the measured stream (for example, its CNAME),
o the SSRC of the measured stream,
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).
Note that this set of information may overlap with, but is more
extensive than, that in the union of similar information in RTCP RR
packets. However we can not assume that RR information is always
present when XR is sent, since they may have different measurement
intervals. Also the reason for the additional information carried in
the XR is the perceived difficulty of "locating" the *start* of the
RTP session (sequence number of 1st packet, duration of interval
applicable to cumulative measurements) using only RR. However when
an RTCP XR packet containing more than two metrics blocks, reporting
on the same streams from the same source, each metric block should
have the same measurement identity, if each metric block carry the
duplicated data for the measurement identity ,it leads to redundant
information in this design since equivalent information is provided
multiple times, once in *every* identification packet. Though this
ensures immunity to packet loss, the design bring more complexity and
the overhead is not completely trivial.
This section proposes an approach to minimise the inefficiency of
providing this identification information, assuming that an
architecture based on small blocks means that a typical RTCP packet
will contain more than one metrics block needing the same
identification. The choice of identification information to be
provided is discussed in [IDENTITY]. The approach is to define a
stand-alone block containing only identification information within
the scope of the containing RTCP XR packet. The "containing RTCP XR
packet" is defined here as the RTCP XR header with PT=XR=207 defined
in Section 2 of [RFC3611] and the associated payload defined by the
length field of this RTCP XR header. The RTCP XR header itself
includes the SSRC of the node at which all of the contained metrics
were measured, hence this SSRC need not be repeated in the stand-
alone identification block. A single containing RTCP XR packet may
Wu, et al. Expires November 28, 2011 [Page 11]
Internet-Draft RTP Monitoring Architectures May 2011
contain multiple identification blocks limited by the range of the
tag field. Typically there will be one identification block per
monitored source SSRC, but the use of more than one identification
block for a single monitored source SSRC within a single containing
RTCP XR packet is not ruled out. In order to reduce overhead of the
payload, This stand-alone block need only be exchanged occasionally,
for example sent once at the start of a session.
5.3. Correlating identity information with the data
This section proposes an approach to facilitate the correlation of
the metrics report blocks with other session-related data or identity
data, i.e., using correlation tag to associate identity information
with the data.
For example, there will be zero or more metrics blocks dependent on
the same set of identity information. The dependence of an instance
of a metrics block on such identity information can be established by
the metrics block's having the same numeric value of the tag field.
Also there will be an identity data dependent on the same set of
identity information. If the set of identity information is formed
as an independent block, then the dependence of an instance of a
identity block on identity data can be established by the identity
block's having the tag field to indicate the relationship between
identity blocks and a specific application. An example use case is
for an endpoint may convey a call identifier or a global call
identifier associated with identity information. A flow measurement
tool that is not call-aware can then forward the metric reports along
with this correlation tag to network management. Network management
can then use this tag to correlate this report with other diagnostic
information such as call detail records.
Wu, et al. Expires November 28, 2011 [Page 12]
Internet-Draft RTP Monitoring Architectures May 2011
6. An example of a metric block
This section uses the example of an existing proposed metrics block
to illustrate the application of the principles set out in
Section 5.1.
The example [PDV] (work in progress) is a block to convey information
about packet delay variation (PDV) only, consistent with the
principle that a metrics block should address only one parameter of
interest. One simple metric of PDV is available in the RTCP RR
packet as the "jit" field. There are other PDV metrics which may be
more useful to certain applications. Two such metrics are the IPDV
metric ([Y1540], [RFC3393]) and the MAPDV2 metric [G1020]. Use of
these metrics is consistent with the principle in Section 5 of
[RFC5968] that metrics should usually be defined elsewhere, so that
RTCP standards define only the transport of the metric rather than
its nature. The purpose of this section is to illustrate the
architecture using the example of [PDV] (work in progress) rather
than to document the design of the PDV metrics block or to provide a
tutorial on PDV in general.
Given the availability of at least three metrics for PDV, there are
design options for the allocation of metrics to RTCP XR blocks:
o provide an RTCP XR block per metric
o provide a single RTCP XR block which contains all three metrics
o provide a single RTCP block to convey any one of the three
metrics, together with a identifier to inform the receiving RTP
system of the specific metric being conveyed
In choosing between these options, extensibility is important,
because additional metrics of PDV may well be standardized and
require inclusion in this framework. The first option is extensible
but only by use of additional RTCP XR blocks, which may consume the
limited namespace for RTCP XR blocks at an unacceptable rate. The
second option is not extensible, so could be rejected on that basis,
but in any case a single application is quite unlikely to require
transport of more than one metric for PDV. Hence the third option
was chosen. This implies the creation of a subsidiary namespace to
enumerate the PDV metrics which may be transported by this block, as
discussed further in [PDV] (work in progress).
Wu, et al. Expires November 28, 2011 [Page 13]
Internet-Draft RTP Monitoring Architectures May 2011
7. Application to RFC 5117 topologies
The topologies specified in [RFC5117] fall into two categories. The
first category relates to the RTP system model utilizing multicast
and/or unicast. The topologies in this category are specifically
Topo-Point-to-Point, Topo- Multicast, Topo-Translator (both variants,
Topo-Trn-Translator and Topo-Media-Translator, and combinations of
the two), and Topo-Mixer. These topologies use RTP end systems, RTP
mixers and RTP translators defined in [RFC3550]. For purposes of
reporting connection quality to other RTP systems, RTP mixers and RTP
end systems are very similar. Mixers resynchronize audio packets and
do not relay RTCP reports received from one cloud towards other
cloud(s). Translators do not resynchronize packets and SHOULD
forward certain RTCP reports between clouds. In this category, the
RTP system (end system, mixer or translator) which originates,
terminates or forwards RTCP XR blocks is expected to handle RTCP,
including RTCP XR, according to [RFC3550]. Provided this expectation
is met, an RTP system using RTCP XR is architecturally no different
from an RTP system of the same class (end system, mixer, or
translator) which does not use RTCP XR. The second category relates
to deployed system models used in many H.323 [H323] video
conferences. The topologies in this category are Topo-Video-Switch-
MCU and Topo-RTCP-terminating-MCU. Such topologies based on systems
do not behave according to [RFC3550].
7.1. Applicability to MCU
Topo-Video-Switch-MCU and Topo-RTCP-terminating-MCU, suffer from the
difficulties described in [RFC5117]. These difficulties apply to
systems sending, and expecting to receive, RTCP XR blocks as much as
to systems using other RTCP packet types. For example, a participant
RTP end system may send media to a video switch MCU. If the media
stream is not selected for forwarding by the switch, neither RTCP RR
packets nor RTCP XR blocks referring to the end system's generated
stream will be received at the RTP end system. Strictly the RTP end
system can only conclude that its RTP has been lost in the network,
though an RTP end system complying with the robustness principle of
[RFC1122] should survive with essential functions unimpaired.
7.2. Applicability to Translators
Section 7.2 of [RFC3550] describes processing of RTCP by translators.
RTCP XR is within the scope of the recommendations of [RFC3550].
Some RTCP XR metrics blocks may usefully be measured at, and reported
by, translators. As described in [RFC3550] this creates a
requirement for the translator to allocate an SSRC for the monitor
within itself so that it may populate the SSRC in the RTCP XR packet
header (although the translator is not a Synchronisation Source in
Wu, et al. Expires November 28, 2011 [Page 14]
Internet-Draft RTP Monitoring Architectures May 2011
the sense of originating RTP media packets). It must also supply
this SSRC and the corresponding CNAME in RTCP SDES packets.
In RTP sessions where one or more translators generate any RTCP
traffic towards their next-neighbour RTP system, other translators in
the session have a choice as to whether they forward a translator's
RTCP packets. Forwarding may provide additional information to other
RTP systems in the connection but increases RTCP bandwidth and may in
some cases present a security risk. RTP translators may have
forwarding behaviour based on local policy, which might differ
between different interfaces of the same translator.
For bidirectional unicast, an RTP system may usually detect RTCP XR
from a translator by noting that the sending SSRC is not present in
any RTP media packet. However even for bidirectional unicast there
is a possibility of a source sending RTCP XR before it has sent any
RTP media (leading to transient mis-categorisation of an RTP end
system or RTP mixer as a translator), and for multicast sessions - or
unidirectional/streaming unicast - there is a possibility of a
receive-only end system being permanently mis-categorised as a
translator sending XR report, i.e.,monitor collocated with
transaltor. Hence it is desirable for a translator that sends XR to
have a way to declare itself explicitly.
Wu, et al. Expires November 28, 2011 [Page 15]
Internet-Draft RTP Monitoring Architectures May 2011
8. IANA Considerations
None.
Wu, et al. Expires November 28, 2011 [Page 16]
Internet-Draft RTP Monitoring Architectures May 2011
9. Security Considerations
This document itself contains no normative text and hence should not
give rise to any new security considerations, to be confirmed.
Wu, et al. Expires November 28, 2011 [Page 17]
Internet-Draft RTP Monitoring Architectures May 2011
10. Acknowledgement
The authors would also like to thank Colin Perkins, Graeme Gibbs,
Debbie Greenstreet, Keith Drage,Dan Romascanu, Ali C. Begen, Roni
Even for their valuable comments and suggestions on the early version
of this document.
Wu, et al. Expires November 28, 2011 [Page 18]
Internet-Draft RTP Monitoring Architectures May 2011
11. Informative References
[G1020] ITU-T, "ITU-T Rec. G.1020, Performance parameter
definitions for quality of speech and other voiceband
applications utilizing IP networks", July 2006.
[H323] ITU-T, "ITU-T Rec. H.323, Packet-based multimedia
communications systems", June 2006.
[IDENTITY]
Hunt, G., "RTCP XR Report Block for Measurement Identity",
ID draft-ietf-avt-rtcp-xr-meas-identity-02, May 2009.
[PDV] Hunt, G., "RTCP XR Report Block for Packet Delay Variation
Metric Reporting", ID draft-ietf-avt-rtcp-xr-pdv-03,
May 2009.
[RFC1122] Braden, R., "Requirements for Internet Hosts --
Communication Layers", RFC 1122, October 1989.
[RFC3393] Demichelis, C., "IP Packet Delay Variation Metric for IP
Performance Metrics (IPPM)", RFC 3393, November 2002.
[RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time
Applications", RFC 3550, July 2003.
[RFC3551] Schulzrinne , H. and S. Casner, "Extended RTP Profile for
Real-time Transport Control Protocol (RTCP)-Based Feedback
(RTP/AVPF)", RFC 3551, July 2003.
[RFC3611] Friedman, T., "RTP Control Protocol Extended Reports (RTCP
XR)", RFC 3611, November 2003.
[RFC4585] Ott, J. and S. Wenger, "Extended RTP Profile for Real-time
Transport Control Protocol (RTCP)-Based Feedback (RTP/
AVPF)", RFC 4585, July 2006.
[RFC5117] Westerlund, M., "RTP Topologies", RFC 5117, January 2008.
[RFC5968] Ott, J. and C. Perkins, "Guidelines for Extending the RTP
Control Protocol (RTCP)", RFC 5968, September 2010.
[Y1540] ITU-T, "ITU-T Rec. Y.1540, IP packet transfer and
availability performance parameters", November 2007.
Wu, et al. Expires November 28, 2011 [Page 19]
Internet-Draft RTP Monitoring Architectures May 2011
Appendix A. Change Log
Note to the RFC-Editor: please remove this section prior to
publication as an RFC.
A.1. draft-ietf-avtcore-monarch-00
The following are the major changes compared to
draft-hunt-avtcore-monarch-02:
o Move Geoff Hunt and Philip Arden to acknowledgement section.
A.2. draft-ietf-avtcore-monarch-01
The following are the major changes compared to 00:
o Restructure the document by merging section 4 into section 3.
o Remove section 4.1,section 5 that is out of scope of this
document.
o Remove the last bullet in section 6 and section 7.3 based on
conclusion of last meeting.
o Update figure 1 and related text in section 3 according to the
monitor definition in RFC3550.
o Revise section 9 to address monitor declaration issue.
o Merge the first two bullet in section 6.
o Add one new bullet to discuss metric block association in section
6.
A.3. draft-ietf-avtcore-monarch-02
The following are the major changes compared to 01:
o Deleting first paragraph of Section 1.
o Deleting Section 3.1, since the interaction with the management
application is out of scope of this draft.
o Separeate identity information correlation from section 5.2 as new
section 5.3.
o Remove figure 2 and related text from section 5.2.
Wu, et al. Expires November 28, 2011 [Page 20]
Internet-Draft RTP Monitoring Architectures May 2011
o Editorial changes in the section 4 and the first paragraph of
section 7.
Wu, et al. Expires November 28, 2011 [Page 21]
Internet-Draft RTP Monitoring Architectures May 2011
Authors' Addresses
Qin Wu (editor)
Huawei
101 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: sunseawq@huawei.com
Geoff Hunt
Unaffiliated
Email: r.geoff.hunt@gmail.com
Philip Arden
BT
Orion 3/7 PP4
Adastral Park
Martlesham Heath
Ipswich, Suffolk IP5 3RE
United Kingdom
Phone: +44 1473 644192
Email: philip.arden@bt.com
Wu, et al. Expires November 28, 2011 [Page 22]
