 1/draftietfippmmultimetrics01.txt 20061025 23:12:29.000000000 +0200
+++ 2/draftietfippmmultimetrics02.txt 20061025 23:12:29.000000000 +0200
@@ 1,21 +1,21 @@
Network Working Group E. Stephan
InternetDraft France Telecom
Expires: December 27, 2006 L. Liang
 University of Surrey
+Intended status: Informational L. Liang
+Expires: April 25, 2007 University of Surrey
A. Morton
AT&T Labs
 June 25, 2006
+ October 22, 2006
IP Performance Metrics (IPPM) for spatial and multicast
 draftietfippmmultimetrics01
+ draftietfippmmultimetrics02
Status of this Memo
By submitting this InternetDraft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
InternetDrafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
@@ 26,21 +26,21 @@
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use InternetDrafts as reference
material or to cite them other than as "work in progress."
The list of current InternetDrafts can be accessed at
http://www.ietf.org/ietf/1idabstracts.txt.
The list of InternetDraft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
 This InternetDraft will expire on December 27, 2006.
+ This InternetDraft will expire on April 25, 2007.
Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
The IETF IP Performance Metrics (IPPM) working group has standardized
metrics for measuring endtoend performance between 2 points. This
memo defines 2 sets of metrics to extend these endtoend ones. It
@@ 51,48 +51,48 @@
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. Multiparty metric . . . . . . . . . . . . . . . . . . . . 5
2.2. Spatial metric . . . . . . . . . . . . . . . . . . . . . . 5
2.3. Spatial metric points of interest . . . . . . . . . . . . 5
2.4. Onetogroup metric . . . . . . . . . . . . . . . . . . . 5
2.5. Onetogroup metric points of interest . . . . . . . . . . 5
2.6. Reference point . . . . . . . . . . . . . . . . . . . . . 5
 2.7. Group of singletons . . . . . . . . . . . . . . . . . . . 6
 3. Motivations for spatial and onetogroup metrics . . . . . . . 6
 3.1. spatial metrics . . . . . . . . . . . . . . . . . . . . . 6
 3.2. Onetogroup metrics . . . . . . . . . . . . . . . . . . . 7
 3.3. Discussion on Grouptoone and Grouptogroup metrics . . 8
 4. Spatial metrics definitions . . . . . . . . . . . . . . . . . 8
 4.1. A Definition for Spatial Oneway Delay Stream . . . . . . 8
 4.2. A Definition of a sample of Oneway Delay of a sub path . 11
 4.3. A Definition for Spatial Oneway Packet Loss Stream . . . 13
 4.4. A Definition for Spatial Oneway Jitter Stream . . . . . . 15
 4.5. Pure Passive Metrics . . . . . . . . . . . . . . . . . . . 17
 4.6. Discussion on spatial statistics . . . . . . . . . . . . . 19
 5. Onetogroup metrics definitions . . . . . . . . . . . . . . . 19
 5.1. A Definition for onetogroup Oneway Delay Stream . . . . 19
 5.2. A Definition for onetogroup Oneway Packet Loss
 Stream . . . . . . . . . . . . . . . . . . . . . . . . . . 20
 5.3. A Definition for onetogroup Oneway Jitter Stream . . . 21
 5.4. Discussion on onetogroup statistics . . . . . . . . . . 22
 6. Extension from onetoone to onetomany measurement . . . . . 24
 7. Open issues . . . . . . . . . . . . . . . . . . . . . . . . . 25
 8. Security Considerations . . . . . . . . . . . . . . . . . . . 25
 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 25
 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 26
 11.1. Normative References . . . . . . . . . . . . . . . . . . . 26
 11.2. Informative References . . . . . . . . . . . . . . . . . . 26
 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 28
 Intellectual Property and Copyright Statements . . . . . . . . . . 29
+ 2.7. Vector . . . . . . . . . . . . . . . . . . . . . . . . . . 6
+ 2.8. Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . 6
+ 3. Motivations for spatial and onetogroup metrics . . . . . . . 7
+ 3.1. spatial metrics . . . . . . . . . . . . . . . . . . . . . 7
+ 3.2. Onetogroup metrics . . . . . . . . . . . . . . . . . . . 8
+ 3.3. Discussion on Grouptoone and Grouptogroup metrics . . 9
+ 4. Spatial metrics definitions . . . . . . . . . . . . . . . . . 9
+ 4.1. A Definition for Spatial Oneway Delay Vector . . . . . . 10
+ 4.2. A Definition of a sample of Oneway Delay of a sub path . 12
+ 4.3. A Definition for Spatial Oneway Packet Loss Vector . . . 15
+ 4.4. A Definition for Spatial Oneway Jitter Vector . . . . . . 16
+ 4.5. Pure Passive Metrics . . . . . . . . . . . . . . . . . . . 18
+ 4.6. Discussion on spatial statistics . . . . . . . . . . . . . 20
+ 5. Onetogroup metrics definitions . . . . . . . . . . . . . . . 20
+ 5.1. A Definition for onetogroup Oneway Delay . . . . . . . 20
+ 5.2. A Definition for onetogroup Oneway Packet Loss . . . . 21
+ 5.3. A Definition for onetogroup Oneway Jitter . . . . . . . 21
+ 5.4. Discussion on onetogroup statistics . . . . . . . . . . 23
+ 6. Extension from onetoone to onetomany measurement . . . . . 26
+ 7. Open issues . . . . . . . . . . . . . . . . . . . . . . . . . 27
+ 8. Security Considerations . . . . . . . . . . . . . . . . . . . 27
+ 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
+ 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27
+ 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 28
+ 11.1. Normative References . . . . . . . . . . . . . . . . . . . 28
+ 11.2. Informative References . . . . . . . . . . . . . . . . . . 28
+ Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 29
+ Intellectual Property and Copyright Statements . . . . . . . . . . 30
1. Introduction
The metrics specified in this memo are built on notions introduced
and discussed in the IPPM Framework document, RFC 2330 [RFC2330].
The reader should be familiar with these documents.
This memo makes use of definitions of endtoend Oneway Delay
Metrics defined in the RFC 2679 [RFC2679] to define metrics for
decomposition of endtoend oneway delays measurements.
@@ 134,59 +134,59 @@
o Network performance measurement for periodic streams, RFC 3432
[RFC3432];
o Packet Reordering Metric for IPPM [Work in progress];
Based on these works, this memo defines 2 kinds of multi party
metrics.
Firstly it defines spatial metrics:
 o A 'sample', called TypePSpatialOnewayDelayStream, will be
 introduced to decompose an endtoend TypePOnewayDelay in a
+ o A 'sample', called TypePSpatialOnewayDelayVector, will be
+ introduced to divide an endtoend TypePOnewayDelay in a
spatial sequence of oneway delays.
 o A 'sample', called TypePSpatialOnewayPacketLossStream, will
 be introduced to decompose an endtoend TypePOnewayPacket
 Loss in a spatial sequence of packet loss.
+ o A 'sample', called TypePSpatialOnewayPacketLossVector, will
+ be introduced to divide an endtoend TypePOnewayPacketLoss
+ in a spatial sequence of packet loss.
 o Using the TypePSpatialOnewayDelayStream metric, a 'sample',
 called TypePSpatialOnewayJitterStream, will be introduced to
 decompose an endtoend TypePOnewayipdv in a spatial sequence
 of jitter.
+ o Using the TypePSpatialOnewayDelayVector metric, a 'sample',
+ called TypePSpatialOnewayJitterVector, will be introduced to
+ divide an endtoend TypePOnewayipdv in a spatial sequence of
+ jitter.
 o Using the TypePSpatialOnewayDelayStream metric, a 'sample',
+ o Using the TypePSpatialOnewayDelayVector metric, a 'sample',
called TypePsubpathOnewayDelayStream, will be introduced to
 define the onewaydelay between any host of the path.
+ define the onewaydelay between a pair of host of the path. This
+ metric is similar to TypePOnewayDelayStream.
 o Using TypePsubpathxStream, a 'sample' TypePPassivexStream
 will be introduced to define the Passive metrics. These metrics
 are designed for pure passive measurement methodology as
 introduced by PSAMP WG.
+ o Using TypePsubpathOnewayDelayStream, a 'sample' TypeP
+ PassiveOnewayDelayStream will be introduced to define passive
+ metrics. These metrics are designed for pure passive measurement
+ methodology as introduced by PSAMP WG.
Then it defines onetogroup metrics.
o Using one test packet sent from one sender to a group of
receivers, a 'sample', called TypePonetogroupOnewayDelay
 Stream, will be introduced to define the list of TypePoneway
+ Vector, will be introduced to define the list of TypePoneway
delay between this sender and the group of receivers.
o Using one test packet sent from one sender to a group of
receivers, a 'sample', called TypePonetogroupOnewayPacket
 LossStream, will be introduced to define the list of TypePOne
+ LossVector, will be introduced to define the list of TypePOne
wayPacketLoss between this sender and the group of receivers
o Using one test packet sent from one sender to a group of
receivers, a 'sample', called TypePonetogroupOnewayJitter
 Stream, will be introduced to define the list of TypePOneway
+ Vector, will be introduced to define the list of TypePOneway
ipdv between this sender and the group of receivers

o Then a discussion section presents the set of statistics that may
be computed on the top of these metrics to present the QoS in a
view of a group of users as well as the requirements of relative
QoS on multiparty communications.
2. Terminology
2.1. Multiparty metric
A metric is said to be multiparty if the definition involved more
@@ 222,31 +222,72 @@
Points of interest of Onetogroup metrics are the set of host
destinations receiving packets from the source (in addition to the
source itself).
2.6. Reference point
The centre/server in the onetogroup measurement that is controlled
by network operators can be a very good reference point where
measurement data can be collected for further processing although the
actual measurements have to be carried out at all points of interest.

I.e., the measurement points will be all clients/receivers while the
reference point acts as source for the onetogroup metric. Thus, we
can define the reference point as the host while the statistic
calculation will be carried out.
2.7. Group of singletons
+2.7. Vector
A group of singletons is the set of results of the observation of the
behaviour of the same packet at different places of a network.
+ A Vector is a set of singletons, which are a set of results of the
+ observation of the behaviour of the same packet at different places
+ of a network at different time. For instance, if Oneway delay
+ singletons abserved at N receivers for Packet P sent by the source
+ Src are dT1, dT2,..., dTN, it can be say that a vector V with N
+ elements can be orgnized as {dT1, dT2,..., dTN}. The elements in one
+ vector are singletons distinct with each other in terms of both
+ measurement point and time. Given the vector V as an example, the
+ element dT1 is distinct from the rest by measured at receiver 1 at
+ time T1. Additional to a singleton, Vector gives information over a
+ space dimension.
+
+2.8. Matrix
+
+ Several vectors can orgnize form up a Matrix, which contains results
+ observed in a sampling interval at different place of a network at
+ different time. For instance, given Oneway delay vectors V1={dT11,
+ dT12,..., dT1N}, V2={dT21, dT22,..., dT2N},..., Vm={dTm1, dTm2,...,
+ dTmN} for Packet P1, P2,...,Pm, we can have a Oneway delay Matrix
+ {V1, V2,...,Vm}. Additional to the information given by a Vector, a
+ Matrix is more powerful to present network performance in both space
+ and time dimensions. It normally corresponding to a sample.
+
+ The relation among Singleton, Vector and Matrix can be shown in the
+ following Fig 1.
+
+ one to group Singleton
+ / Sample
+ Src Rcvr ..............................
+ ..................R1dT1 R1dT2 R1dT3 R1dT4
+ `:=.._
+ T `._ ``..__
+ `. ` R2dT1 R2dT2 R2dT3 R2dT4
+ `.
+ `.
+ `._R3dT1 R3dT2 R3dT3 R3dT4
+
+ Vector Matrix
+ (space) (time)
+
+ Figure 1.
+
3. Motivations for spatial and onetogroup metrics
All IPPM metrics are defined for endtoend measurement. These
metrics provide very good guides for measurement in the pair
communications. However, further efforts should be put to define
metrics for multiparty measurements such as one to one trajectory
metrics and one to multipoint metrics.
3.1. spatial metrics
@@ 354,39 +394,39 @@
4. Spatial metrics definitions
Spatial decomposition metrics are based on standard endtoend
metrics.
The definition of a spatial metric is coupled with the corresponding
endtoend metric. The methodoly is based on the measure of the same
test packet and parameters of the corresponding endtoend metric.
4.1. A Definition for Spatial Oneway Delay Stream
+4.1. A Definition for Spatial Oneway Delay Vector
This section is coupled with the definition of TypePOnewayDelay.
When a parameter from section 3 of [RFC2679] is first used in this
section, it will be tagged with a trailing asterisk.
Sections 3.5 to 3.8 of [RFC2679] give requirements and applicability
statements for endtoend onewaydelay measurements. They are
applicable to each point of interest Hi involved in the measure.
Spatial onewaydelay measurement SHOULD be respectful of them,
especially those related to methodology, clock, uncertainties and
reporting.
Following we adapt some of them and introduce points specific to
spatial measurement.
4.1.1. Metric Name
 TypePSpatialOnewayDelayStream
+ TypePSpatialOnewayDelayVector
4.1.2. Metric Parameters
+ Src*, the IP address of the sender.
+ Dst*, the IP address of the receiver.
+ i, An integer which ordered the hosts in the path.
+ Hi, exchange points of the path digest.
@@ 409,21 +449,21 @@
4.1.4. Definition
Given a TypeP packet sent by the sender Src at wiretime (first bit)
T to the receiver Dst in the path . Given the
sequence of values such that dT is the
TypePOnewayDelay from Src to Dst and such that for each Hi of the
path, T+dTi is either a real number corresponding to the wiretime
the packet passes (last bit received) Hi, or undefined if the packet
never passes Hi.
 TypePSpatialOnewayDelayStream metric is defined for the path
+ TypePSpatialOnewayDelayVector metric is defined for the path
as the sequence of values
.
4.1.5. Discussion
Following are specific issues which may occur:
o the delay looks to decrease: dTi > DTi+1. this seem typically du
to some clock synchronisation issue. this point is discussed in
the section 3.7.1. "Errors or uncertainties related to Clocks" of
@@ 455,50 +495,50 @@
proceed as follows:
o At each Hi, prepare to capture the packet sent a time T, take a
timestamp Ti', determine the internal delay correction dTi',
extract the timestamp T from the packet, then compute the oneway
delay from Src to Hi: dTi = Ti'  dTi'  T. The oneway delay is
undefined (infinite) if the packet is not detected after the 'loss
threshold' duration;
o Gather the set of dTi of each Hi and order them according to the
 path to build the TypePSpatialOnewayDelayStream metric
+ path to build the TypePSpatialOnewayDelayVector metric
over the path .
It is out of the scope of this document to define how each Hi detects
the packet.
4.1.9. Reporting the metric
Section 3.6 of [RFC2679] indicates the items to report.
4.1.10. Path
It is clear that a endtoend TypePOnewayDelay can't determine
the list of hosts the packet passes throught. Section 3.8.4 of
[RFC2679] says that the path traversed by the packet SHOULD be
reported but is practically impossible to determine.
This part of the job is provide by TypePSpatialOnewayDelay
 Stream metric because each points of interest Hi which capture the
+ Vector metric because each points of interest Hi which capture the
packet is part of the path.
4.2. A Definition of a sample of Oneway Delay of a sub path
This metric is similar to the metric TypePOnewayDelayPoisson
stream defined in [RFC2679] and to the metric TypePOnewayDelay
PeriodicStream defined in [RFC3432].
Nevertheless its definition differs because it is based of the
 decomposition of endtoend Oneway delay using the metric TypeP
 SpatialOnewayDelayStream defined above.
+ division of endtoend Oneway delay using the metric TypePSpatial
+ OnewayDelayVector defined above.
It aims is to define a sample of OnewayDelay between a pair of
hosts of a path usable by active and passive measurements.
Sections 3.5 to 3.8 of [RFC2679] give requirements and applicability
statements for endtoend onewaydelay measurements. They are
applicable to each point of interest Hi involved in the measure.
Subpath onewaydelay measurement SHOULD be respectful of them,
especially those related to methodology, clock, uncertainties and
reporting.
@@ 529,48 +569,53 @@
+ dT1,..., dTn a list of delay.
+ P*, the specification of the packet type.
4.2.3. Metric Units
A sequence of pairs .
T is one of time of the sequence T1...Tn;
 dT is a delay.
+ dt is a delay.
4.2.4. Definition
Given 2 hosts Ha and Hb of the path , given
a flow of packets of TypeP sent from Src to Dst at the times T1,
T2... Tn. At each of these times, we obtain a TypePSpatialOne
 wayDelayStream . We define the
+ wayDelayVector . We define the
value of the sample TypePsubpathOnewayDelayStream as the
sequence made up of the couples . dTk.a is the
delay between Src and Ha. dTk.b is the delay between Src and Hb.
'dTk.b  dTk.a' is the oneway delay experienced by the packet sent
at the time Tk by Src when going from Ha to Hb.
4.2.5. Discussion
Following are specific issues which may occur:
 o The definition permits the measure of when a is
 Src.
+ o When a is Src is the measure of the first hop.
 o The definition permits the measure of when b is
 Dst.
+ o When b is Dst is the measure of the last hop.
 o the delay looks to decrease: dTi > DTi+1. this seem typically du
 to some clock synchronisation issue. this point is discussed in
 the section 3.7.1. "Errors or uncertainties related to Clocks" of
 of [RFC2679];.
+ o the delay looks to decrease: dTi > DTi+1:
+
+ * This is typically du to clock synchronisation issue. this point
+ is discussed in the section 3.7.1. "Errors or uncertainties
+ related to Clocks" of of [RFC2679];
+
+ * This may occurs too when the clock resolution of one probe is
+ bigger than the minimun delay of a path. As an example this
+ happen when measuring the delay of a path which is 500 km long
+ with one probe synchronized using NTP having a clock resolution
+ of 8ms.
o The location of the point of interest in the device influences the
result (see [ID.quittekipfixmiddlebox]). If the packet is not
observed on the input interface the delay includes buffering time
and consequently an uncertainty due to the difference between
'wire time' and 'host time';
o dTk.b may be observed and not dTk.a.
o Tk is unknown if the flow is made of end user packets, that is
@@ 591,39 +636,39 @@
4.2.8. Methodologies
Both active and passive method should discussed.
4.2.9. Reporting the metric
Section 3.6 of [RFC2679] indicates the items to report.
4.2.10. Path
4.3. A Definition for Spatial Oneway Packet Loss Stream
+4.3. A Definition for Spatial Oneway Packet Loss Vector
This section is coupled with the definition of TypePOnewayPacket
Loss. Then when a parameter from the section 2 of [RFC2680] is first
used in this section, it will be tagged with a trailing asterisk.
Sections 2.5 to 2.8 of [RFC2680] give requirements and applicability
statements for endtoend onewayPacketLoss measurements. They are
applicable to each point of interest Hi involved in the measure.
Spatial packet loss measurement SHOULD be respectful of them,
especially those related to methodology, clock, uncertainities and
reporting.
Following we define the spatial metric, then we adapt some of the
points above and introduce points specific to spatial measurement.
4.3.1. Metric Name
 TypePSpatialOnewayPacketLossStream
+ TypePSpatialOnewayPacketLossVector
4.3.2. Metric Parameters
+ Src*, the IP address of the sender.
+ Dst*, the IP address of the receiver.
+ i, An integer which ordered the hosts in the path.
+ Hi, exchange points of the path digest.
@@ 642,21 +687,22 @@
4.3.3. Metric Units
A sequence of boolean values.
4.3.4. Definition
Given a TypeP packet sent by the sender Src at time T to the
receiver Dst in the path . Given the sequence of
times the packet passes ,
 TypePOnewayPacketLostStream metric is defined as the sequence
+
+ TypePOnewayPacketLostVector metric is defined as the sequence
of values such that for each Hi of the path, a
value of Bi of 0 means that dTi is a finite value, and a value of 1
means that dTi is undefined.
4.3.5. Discussion
Following are specific issues wich may occur:
o the result includes the sequence 1,0. This case means that the
packet was seen by a host but not by it successor on the path;
@@ 665,39 +711,39 @@
The location of the meter in the device influences the result:
o Even if the packet is received by a device, it may be not observed
by a meter located after a buffer;
4.3.6. Reporting
Section in progress.
4.4. A Definition for Spatial Oneway Jitter Stream
+4.4. A Definition for Spatial Oneway Jitter Vector
This section uses parameters from the definition of TypePOneway
ipdv. When a parameter from section 2 of [RFC3393] is first used in
this section, it will be tagged with a trailing asterisk.
Sections 3.5 to 3.7 of [RFC3393] give requirements and applicability
statements for endtoend onewayipdv measurements. They are
applicable to each point of interest Hi involved in the measure.
Spatial onewayipdv measurement SHOULD be respectful of them,
especially those related to methodology, clock, uncertainities and
reporting.
Following we adapt some of them and introduce points specific to
spatial measurement.
4.4.1. Metric Name
 TypePSpatialOnewayJitterStream
+ TypePSpatialOnewayJitterVector
4.4.2. Metric Parameters
+ Src*, the IP address of the sender.
+ Dst*, the IP address of the receiver.
+ i, An integer which ordered the hosts in the path.
+ Hi, exchange points of the path digest.
@@ 708,52 +754,52 @@
+ P, the specification of the packet type.
+ P1, the first packet sent at time T1.
+ P2, the second packet sent at time T2.
+ , a path digest.
+ ,
 the TypePSpatialOnewayDelayStream for packet sent at
+ the TypePSpatialOnewayDelayVector for packet sent at
time T1;
+ ,
 the TypePSpatialOnewayDelayStream for packet sent at
+ the TypePSpatialOnewayDelayVector for packet sent at
time T2;
+ L*, a packet length in bits. The packets of a Type P
packet stream from which the
 TypePSpatialOnewayDelayStream metric is taken MUST
+ TypePSpatialOnewayDelayVector metric is taken MUST
all be of the same length.
4.4.3. Metric Units
A sequence of times.
4.4.4. Definition
Given the TypeP packet having the size L and sent by the sender Src
at wiretime (first bit) T1 to the receiver Dst in the path .
Given the TypeP packet having the size L and sent by the sender Src
at wiretime (first bit) T2 to the receiver Dst in the same path.
 Given the TypePSpatialOnewayDelayStream of the packet P1.
 Given the TypePSpatialOnewayDelayStream of the packet P2.
 TypePSpatialOnewayJitterStream metric is defined as the
+ TypePSpatialOnewayJitterVector metric is defined as the
sequence of values Such that for each Hi of the path ,
dT2.idT1.i is either a real number if the packets P1 and P2 passes
Hi at wiretime (last bit) dT1.i, respectively dT2.i, or undefined if
at least one of them never passes Hi. T2T1 is the interpacket
emission interval and dT2dT1 is ddT* the TypePOnewayipdv at
T1,T2*.
4.4.5. Sections in progress
@@ 811,61 +857,45 @@
of method of detection (expecting Seq++); because of the difference
of source of time (H1 vs Src) and because of the difference of
behavior of the source (Poisson/unknown).
4.5.3. naming and registry
Having distinct metrics identifiers for spatial metrics and passive
spatial metrics in the [RFC4148] will avoid interoperabily issues
especially during composition of metrics.
 They may be named

 o TypePPassiveOnewaydelayStream

 o TypePPassiveOnewayPacketLossStream

 o TypePPassiveOnewayjitterStream

 In the same way sample should be registred too. they may be named

 o TypePPassiveOnewaydelaySample

 o TypePPassiveOnewayPacketLossSample

 o TypePPassiveOnewayjitterSample

4.5.4. Passive One way delay metrics
4.5.5. Passive One way PacketLoss metrics
4.5.6. Passive One way jitter metrics
4.6. Discussion on spatial statistics
Do we define min, max, avg of spatial metrics ?
having the maximum loss metric value could be interesting. Say,
the segment between router A and B always contributes loss metric
value of "1" means it could be the potential problem segment.
Uploading dTi of each Hi consume a lot of bandwidth. Computing
statistics (min, max and avg) of dTi locally in each Hi reduce the
bandwidth consumption.
5. Onetogroup metrics definitions
5.1. A Definition for onetogroup Oneway Delay Stream
+5.1. A Definition for onetogroup Oneway Delay
5.1.1. Metric Name
 TypePonetogroupOnewayDelayStream
+ TypePonetogroupOnewayDelayVector
5.1.2. Metric Parameters
o Src, the IP address of a host acting as the source.
o Recv1,..., RecvN, the IP addresses of the N hosts acting as
receivers.
o T, a time.
@@ 876,70 +906,70 @@
o Gr, the multicast group address (optional). The parameter Gr is
the multicast group address if the measured packets are
transmitted by multicast. This parameter is to identify the
measured traffic from other unicast and multicast traffic. It is
set to be optional in the metric to avoid losing any generality,
i.e. to make the metric also applicable to unicast measurement
where there is only one receivers.
5.1.3. Metric Units
 The value of a TypePonetogroupOnewayDelayStream is a set of
+ The value of a TypePonetogroupOnewayDelayVector is a set of
singletons metrics TypePOnewayDelay [RFC2679].
5.1.4. Definition
Given a Type P packet sent by the source Src at Time T, given the N
hosts { Recv1,...,RecvN } which receive the packet at the time {
 T+dT1,...,T+dTn }, a TypePonetogroupOnewayDelayStream is
+ T+dT1,...,T+dTn }, a TypePonetogroupOnewayDelayVector is
defined as the set of the TypePOnewayDelay singleton between Src
and each receiver with value of { dT1, dT2,...,dTn }.
5.2. A Definition for onetogroup Oneway Packet Loss Stream
+5.2. A Definition for onetogroup Oneway Packet Loss
5.2.1. Metric Name
 TypePonetogroupOnewayPacketLossStream
+ TypePonetogroupOnewayPacketLossVector
5.2.2. Metric Parameters
o Src, the IP address of a host acting as the source.
o Recv1,..., RecvN, the IP addresses of the N hosts acting as
receivers.
o T, a time.
o T1,...,Tn a list of time.
o P, the specification of the packet type.
o Gr, the multicast group address (optional).
5.2.3. Metric Units
 The value of a TypePonetogroupOnewayPacketLossStream is a
+ The value of a TypePonetogroupOnewayPacketLossVector is a
set of singletons metrics TypePOnewayPacketLoss [RFC2680].
5.2.4. Definition
Given a Type P packet sent by the source Src at T and the N hosts,
Recv1,...,RecvN, which should receive the packet at T1,...,Tn, a
 TypePonetogroupOnewayPacketLossStream is defined as a set of
+ TypePonetogroupOnewayPacketLossVector is defined as a set of
the TypePOnewayPacketLoss singleton between Src and each of the
receivers {,,..., }.
5.3. A Definition for onetogroup Oneway Jitter Stream
+5.3. A Definition for onetogroup Oneway Jitter
5.3.1. Metric Name
 TypePonetogroupOnewayJitterStream
+ TypePonetogroupOnewayJitterVector
5.3.2. Metric Parameters
+ Src, the IP address of a host acting as the source.
+ Recv1,..., RecvN, the IP addresses of the N hosts acting as
receivers.
+ T1, a time.
@@ 949,163 +979,226 @@
+ P, the specification of the packet type.
+ F, a selection function defining unambiguously the two
packets from the stream selected for the metric.
+ Gr, the multicast group address (optional)
5.3.3. Metric Units
 The value of a TypePonetogroupOnewayJitterStream is a set of
+ The value of a TypePonetogroupOnewayJitterVector is a set of
singletons metrics TypePOnewayipdv [RFC3393].
5.3.4. Definition
Given a Type P packet stream, TypePonetogroupOneway Jitter
 Stream is defined for two packets from the source Src to the N hosts
+ Vector is defined for two packets from the source Src to the N hosts
{Recv1,...,RecvN },which are selected by the selection function F, as
the difference between the value of the TypePonetogroupOneway
 DelayStream from Src to { Recv1,..., RecvN } at time T1 and the
 value of the TypePonetogroup OnewayDelayStream from Src to {
+ DelayVector from Src to { Recv1,..., RecvN } at time T1 and the
+ value of the TypePonetogroup OnewayDelayVector from Src to {
Recv1,...,RecvN } at time T2. T1 is the wiretime at which Scr sent
the first bit of the first packet, and T2 is the wiretime at which
Src sent the first bit of the second packet. This metric is derived
 from the TypePoneto groupOnewayDelayStream metric.
+ from the TypePoneto groupOnewayDelayVector metric.
Therefore, for a set of real number {ddT1,...,ddTn},TypePone to
 groupOnewayJitterStream from Src to { Recv1,...,RecvN } at T1, T2
+ groupOnewayJitterVector from Src to { Recv1,...,RecvN } at T1, T2
is {ddT1,...,ddTn} means that Src sent two packets, the first at
wiretime T1 (first bit), and the second at wiretime T2 (first bit)
and the packets were received by { Recv1,...,RecvN } at wiretime
{dT1+T1,...,dTn+T1}(last bit of the first packet), and at wiretime
{dT'1+T2,...,dT'n+T2} (last bit of the second packet), and that
{dT'1dT1,...,dT'ndTn} ={ddT1,...,ddTn}.
5.4. Discussion on onetogroup statistics
The defined onetogroup metrics above can all be directly achieved
from the relevant unicast oneway metrics. They managed to collect
all unicast measurement results of oneway metrics together in one
profile and sort them by receivers and packets in a multicast group.
They can provide sufficient information regarding the network
performance in terms of each receiver and guide engineers to identify
potential problem happened on each branch of a multicast routing
tree. However, these metrics can not be directly used to
conveniently present the performance in terms of a group and neither
 to identify the relative QoS situation.
+ to identify the relative performance situation.
One may say that no matter how many people join the communication,
the connections can still be treated as a set of onetoone
connection. However, we might not describe a multiparty
communication by a set of oneway measurement metrics because of the
difficulty for understanding and the lack of convenience. For
instance, an engineer might not describe the connections of a
multiparty online conference in terms of onetogroup oneway delay
for user A and B, B and C, and C and A because people might be
confused. If there are more users in the same communication, the
description might be very long. And he might use the oneway metrics
 with worst and the best value to give users an idea of the QoS range
 of the service they are providing. But it is not clear enough and
 might not be accurate in a large multiparty communication scenario.
+ with worst and the best value to give users an idea of the
+ performance range of the service they are providing. But it is not
+ clear enough and might not be accurate in a large multiparty
+ communication scenario.
 From the QoS point of view, the multiparty communication services not
 only require the absolute QoS support but also the relative QoS. The
 relative QoS means the difference between absolute QoS of all users.
 Directly using the oneway metrics cannot present the relative QoS
+ From the performance point of view, the multiparty communication
+ services not only require the absolute performance support but also
+ the relative performance. The relative performance means the
+ difference between absolute performance of all users. Directly using
+ the oneway metrics cannot present the relative performance
situation. However, if we use the variations of all users oneway
parameters, we can have new metrics to measure the difference of the
 absolute QoS and hence provide the threshold value of relative QoS
 that a multiparty service might demand. A very good example of the
 high relative QoS requirement is the online gaming. A very light
 worse delay will result in failure in the game. We have to use the
 new statistic metrics to define exactly how small the relative delay
 the online gaming requires. There are many other services, e.g.
 online biding, online stock market, etc., need a rule to judge the
 relative QoS requirement. Therefore, we can see the importance of
 new statistic metrics to feed this need.
+ absolute performance and hence provide the threshold value of
+ relative performance that a multiparty service might demand. A very
+ good example of the high relative performance requirement is the
+ online gaming. A very light worse delay will result in failure in
+ the game. We have to use the new statistic metrics to define exactly
+ how small the relative delay the online gaming requires. There are
+ many other services, e.g. online biding, online stock market, etc.,
+ need a rule to judge the relative performance requirement.
+ Therefore, we can see the importance of new statistic metrics to feed
+ this need.
 We might use some onetogroup statistic conceptions to present the
 group performance and relative QoS. In this stage, we define oneto
 group mean stream and onetogroup variation stream. These
 statistics are offered mostly to be illustrative of what could be
 done.
+ We might use some onetogroup statistic conceptions to present and
+ report the group performance and relative performance to save the
+ report transmission bandwidth. Statistics have been defined for One
+ way metrics in corresponding FRCs. They provide the foundation of
+ definition for performance statistics. For instance, there are
+ definitions for minimum and maximum Oneway delay in [RFC2679] and
+ Oneway delay mean in [ID.ietfippmspatialcomposition]. However,
+ there is a dramatic difference between the statistics for onetoone
+ communications and for onetomany communications. The former one
+ only has statistics over the time dimension while the later one can
+ have statistics over both time dimension and space dimention. This
+ space dimension is introduced by the Matrix concept. For a Matrix M
+ shown in the Fig. 2, each row is a set of Oneway singletons
+ spreading over the space dimension and each colume is another set of
+ Oneway singletons spreading over the time dimension.
 Onetogroup mean streams are trying to measure the overall QoS for a
+ (preamble)
+ / \
+  dT11, dT12,..., dT1N 
+  dT21, dT22,..., dT2N 
+  : 
+  : 
+  dTm1, dTm2,..., dTmN 
+ \ /
+
+ Fig. 2 Matrix M (m*N)
+
+ In Matrix M, each element is a Oneway delay singleton. Each row is
+ a delay vector contains the Oneway delays of the same packet
+ observed at N points of interest. It implies the geographical factor
+ of the performance within a group. Each colume is a set of Oneway
+ delays observed during a sampling interval at one of the points of
+ interest. It presents the delay performance at a receiver over the
+ time dimension.
+
+ Therefore, one can either calculate statistics by rows over the space
+ dimension or by columes over the time dimension. It's up to the
+ operators or service provides which dimension they are interested in.
+ For example, a TV broadcast service provider might want to know the
+ statistical performance of each user in a long term run to make sure
+ their services are acceptable and stable. While for an online gaming
+ service provider, he might be more interested to know if all users
+ are served farely by calculating the statistics over the space
+ dimension. This memo does not intent to recommend which of the
+ statistics are better than the other.
+
+ To save the report transmission bandwidth, each point of interest can
+ send statistics in a predefined time interval to the reference point
+ rather than sending every Oneway singleton it observed. As long as
+ an appropriate time interval is decided, appropriate stantistics can
+ represent the performance in a certain accurate scale. How to decide
+ the time interval and how to bootstrap all points of interest and the
+ reference point depend on applications. For instance, applications
+ with lower transmission rate can have the time interval longer and
+ ones with higher transmission rate can have the time interval
+ shorter. However, this is out of the scope of this memo.
+
+ Moreover, after knowing the statistics over the time dimension, one
+ might want to know how this statistics distributed over the space
+ dimension. For instance, a TV broadcast service provider had the
+ performance Matrix M and calculated the Oneway delay mean over the
+ time dimension to obtain a delay Vector as {V1,V2,..., VN}. He then
+ calculated the mean of all the elements in the Vector to see what
+ level of delay he has served to all N users. This new delay mean
+ gives information on how good the service has been delivered to a
+ group of users during a sampling interval in terms of delay. It
+ needs twice calculation to have this statistic over both time and
+ space dimensions. We name this kind of statistics 2level statistics
+ to distinct with those 1level statistics calculated over either
+ space or time dimension. It can be easily prove that no matter over
+ which dimension a 2level statistic is calculated first, the results
+ are the same. I.e. one can calculate the 2level delay mean using
+ the Matrix M by having the 1level delay mean over the time dimension
+ first and then calculate the mean of the obtained vector to find out
+ the 2level delay mean. Or, he can do the 1level statistic
+ calculation over the space dimention first and then have the 2level
+ delay mean. Both two results will be exactly the same. Therefore,
+ when define a 2level statistic, it is no need to specify in which
+ procedure the calculation should follow.
+
+ There are many statistics can be defined for the proposed oneto
+ group metrics over either the space dimension or the time dimension
+ or both. In this memo, we define onetogroup mean and onetogroup
+ variation over the space dimension. These statistics are offered
+ mostly to be illustrative of what could be done.
+
+ Onetogroup mean are trying to measure the overall performance for a
multicast group associated to one source. It is a reflection of the
 absolute QoS of a multiparty communication service when we treat all
 receivers as one customer. It can also present the trend of the
 absolute QoS of all receivers, i.e., it shows that most of the
 receivers in the multiparty communication service trend to receive an
 absolute QoS close to the mean.
+ absolute performance of a multiparty communication service when we
+ treat all receivers as one customer. It can also present the trend
+ of the absolute performance of all receivers, i.e., it shows that
+ most of the receivers in the multiparty communication service trend
+ to receive an absolute performance close to the mean.
 Onetogroup variation streams are trying to measure how the QoS
 varies among all of the users in a multicast group associated to one
 source. The word "variation" in this memo is the population standard
 deviation. It reflects the relative QoS situation in a multiparty
 communication service, i.e., the level of the difference between the
 absolute QoS of each receivers.
+ Onetogroup variation streams are trying to measure how the
+ performance varies among all of the users in a multicast group
+ associated to one source. The word "variation" in this memo is the
+ population standard deviation. It reflects the relative
+ performancesituation in a multiparty communication service, i.e., the
+ level of the difference between the absolute performanceof each
+ receivers.
Using the onetogroup mean and onetogroup variation concepts, we
 can have a much clear understand on the QoS of a multiparty
+ can have a much clear understand on the performanceof a multiparty
communication service in terms of its trend and range. There can be
mean and variation stream definitions for each of the three oneto
group metrics defined above. We only present the definition of Type
 PonetogroupOneway DelayMeanStream and TypePonetogroup
 OnewayDelayVariationStream as examples in this memo.
+ PonetogroupOnewayDelaySpaceMean and TypePonetogroup One
+ wayDelaySpaceVariation as examples in this memo.
5.4.1. TypePonetogroupOnewayDelayMeanStream
+5.4.1. TypePonetogroupOnewayDelaySpaceMean
 Given a TypePonetogroupOnewayDelayStream, the mean stream of
 all { dT1, dT2,...,dTn } for the packet from Src at time T to {
 Recv1,...,RecvN }.
+ Given a TypePonetogroupOnewayDelayVector, the mean { dT1,
+ dT2,...,dTN } for the packet from Src at time T to { Recv1,...,RecvN
+ }.
 For example, suppose we take a sample and the results are:
+ For example, suppose we take a delay vector and the results is:
 Delay_Stream = <
 {T1,...,Tn}
 {T'1,...,T'n}
 {T''1,...T''n}
 >
+ Delay_Vector = {dT1,...,dTN}
 Then the mean stream would be:
+ Then the mean over space dimension would be:
 Delay_Mean_Stream = <
 DM1
 DM2
 DM3
 >
 = <
 sum{T1,...,Tn}/n
 sum{T'1,...,T'n}/n
 sum{T''1,...T''n}/n
 >
+ Delay_Space_Mean = DsM = sum{dT1,...,dTN}/N
5.4.2. TypePonetogroupOnewayDelayVariationStream
 Given a TypePonetogroupOnewayDelayStream, the variation
 stream of all { dT1, dT2,...,dTn } for the packet from Src at time T
 to { Recv1,...,RecvN }.
+ Given a TypePonetogroupOnewayDelayVector, the variation {
+ dT1, dT2,...,dTN } for the packet from Src at time T to {
+ Recv1,...,RecvN }.
 We still take the above Delay_Stream as a sample and the variation
 stream would be:
+ We still take the above Delay_Vector as an sample and the variation
+ would be:
 Delay_Variation_Stream = <
 DV1
 DV2
 DV3
 >
 =<
 (SUM{(T1DM1)^2,...,(TnDM1)^2)}/n)^(1/2)
 (SUM{(T'1DM2)^2,...,(T'nDM2)^2)}/n)^(1/2)
 (SUM{(T''1DM3)^2,...,(T''nDM3)^2)}/n)^(1/2)
 >
+ Delay_Variation_Stream = {SUM[(dT1DsM)^2,...,(dTN
+ DsM)^2)}/N)^(1/2)
6. Extension from onetoone to onetomany measurement
The above onetogroup metrics were defined to compose measurement
results of a group of users who receive the same data from one
source. Moreover, this is one of efforts to introducing the oneto
many concern to the IPPM working group with respect to the fact that
all existing documents in the group are unicast oriented, which talk
about only onetoone single "path" in measurements. This concept
can be extended from the "path" to "path tree" to cover both oneto
@@ 1122,40 +1215,38 @@
statistic metrics for onetoone communications are exactly the one
togroup metrics themselves when calculated using the methods given.
7. Open issues
8. Security Considerations
Active measumrement: see security section in owd pl, jitter rfcs
(editor notes: add references).
 passive measurement: The rate of packet sampling is controled by hash
 funcion. The analysis of such a function to generate packets that
 match the hash funcion may lead to a DoS attack toward the collector.
+ passive measurement:
+
+ The generation of packets which match systematically the hash
+ function may lead to a DoS attack toward the collector.
+
The generation of packets with spoofing adresses may corrupt the
results without any possibility to detect the spoofing.
 TODO: onetogroup metrics defined here are not intrusive: they rely
 on measures of owd... nevertheless they require collection of
 singletons which may overload the network the measurement controller
 is attach to.

 The onetogroup metrics are derived from oneway metrics and
 therefore, they have very close relationship.
+ onetogroup metrics require collection of singletons which may
+ overload the network the measurement controller is attach to.
9. Acknowledgments
Lei would like to acknowledge Zhili Sun from CCSR, University of
Surrey, for his instruction and helpful comments on this work.
10. IANA Considerations
+
Metrics defined in this memo will be registered in the IANA IPPM
METRICS REGISTRY as described in initial version of the registry
[RFC4148].
11. References
11.1. Normative References
[RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis,
"Framework for IP Performance Metrics", RFC 2330,
@@ 1170,28 +1261,28 @@
[RFC3393] Demichelis, C. and P. Chimento, "IP Packet Delay Variation
Metric for IP Performance Metrics (IPPM)", RFC 3393,
November 2002.
[RFC4148] Stephan, E., "IP Performance Metrics (IPPM) Metrics
Registry", BCP 108, RFC 4148, August 2005.
11.2. Informative References
[ID.boschiipfixreducingredundancy]
 Boschi, E. and L. Mark, "Reducing redundancy in IPFIX and
 PSAMP reports", draftboschiipfixreducingredundancy01
 (work in progress), March 2006.
+ Boschi, E., "Reducing redundancy in IPFIX and PSAMP
+ reports", draftboschiipfixreducingredundancy02 (work
+ in progress), June 2006.
[ID.ietfippmspatialcomposition]
Morton, A. and E. Stephan, "Spatial Composition of
 Metrics", draftietfippmspatialcomposition00 (work in
 progress), February 2006.
+ Metrics", draftietfippmspatialcomposition01 (work in
+ progress), June 2006.
[ID.quittekipfixmiddlebox]
Quittek, J., "Guidelines for IPFIX Implementations on
Middleboxes", draftquittekipfixmiddlebox00 (work in
progress), February 2004.
[RFC2678] Mahdavi, J. and V. Paxson, "IPPM Metrics for Measuring
Connectivity", RFC 2678, September 1999.
[RFC2681] Almes, G., Kalidindi, S., and M. Zekauskas, "A Roundtrip
@@ 1213,39 +1304,55 @@
April 2004.
Authors' Addresses
Stephan Emile
France Telecom Division R&D
2 avenue Pierre Marzin
Lannion, F22307
Fax: +33 2 96 05 18 52
 Email: emile.stephan@francetelecom.com
+ Email: emile.stephan@orangeft.com
Lei Liang
CCSR, University of Surrey
Guildford
Surrey, GU2 7XH
Fax: +44 1483 683641
Email: L.Liang@surrey.ac.uk
Al Morton
200 Laurel Ave. South
Middletown, NJ 07748
USA
Phone: +1 732 420 1571
Email: acmorton@att.com
Intellectual Property Statement
+Full Copyright Statement
+
+ Copyright (C) The Internet Society (2006).
+
+ This document is subject to the rights, licenses and restrictions
+ contained in BCP 78, and except as set forth therein, the authors
+ retain all their rights.
+
+ This document and the information contained herein are provided on an
+ "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
+ OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
+ ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
+ INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
+ INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
+ WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
@@ 1255,30 +1362,14 @@
such proprietary rights by implementers or users of this
specification can be obtained from the IETF online IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietfipr@ietf.org.
Disclaimer of Validity

 This document and the information contained herein are provided on an
 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
 ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
 INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Copyright Statement

 Copyright (C) The Internet Society (2006). This document is subject
 to the rights, licenses and restrictions contained in BCP 78, and
 except as set forth therein, the authors retain all their rights.

Acknowledgment
 Funding for the RFC Editor function is currently provided by the
 Internet Society.
+ Funding for the RFC Editor function is provided by the IETF
+ Administrative Support Activity (IASA).