draft-ietf-ippm-multimetrics-05.txt   draft-ietf-ippm-multimetrics-06.txt 
Network Working Group E. Stephan Network Working Group E. Stephan
Internet-Draft France Telecom Internet-Draft France Telecom
Intended status: Informational L. Liang Intended status: Informational L. Liang
Expires: May 21, 2008 University of Surrey Expires: August 17, 2008 University of Surrey
A. Morton A. Morton
AT&T Labs AT&T Labs
November 18, 2007 February 14, 2008
IP Performance Metrics (IPPM) for spatial and multicast IP Performance Metrics (IPPM) for spatial and multicast
draft-ietf-ippm-multimetrics-05 draft-ietf-ippm-multimetrics-06
Status of this Memo Status of this Memo
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Copyright Notice Copyright Notice
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2008).
Abstract Abstract
The IETF IP Performance Metrics (IPPM) working group has standardized The IETF IP Performance Metrics (IPPM) working group has standardized
metrics for measuring end-to-end performance between two points. metrics for measuring end-to-end performance between two points.
This memo defines two new categories of metrics that extend the This memo defines two new categories of metrics that extend the
coverage to multiple measurement points. It defines spatial metrics coverage to multiple measurement points. It defines spatial metrics
for measuring the performance of segments of a source to destination for measuring the performance of segments of a source to destination
path, and metrics for measuring the performance between a source and path, and metrics for measuring the performance between a source and
many destinations in multiparty communications (e.g., a multicast many destinations in multiparty communications (e.g., a multicast
tree). tree).
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1. Path Digest Hosts . . . . . . . . . . . . . . . . . . . . 6 2.1. Path Digest Hosts . . . . . . . . . . . . . . . . . . . . 6
2.2. Multiparty metric . . . . . . . . . . . . . . . . . . . . 6 2.2. Multiparty metric . . . . . . . . . . . . . . . . . . . . 6
2.3. Spatial metric . . . . . . . . . . . . . . . . . . . . . . 6 2.3. Spatial metric . . . . . . . . . . . . . . . . . . . . . . 6
2.4. One-to-group metric . . . . . . . . . . . . . . . . . . . 6 2.4. One-to-group metric . . . . . . . . . . . . . . . . . . . 6
2.5. Points of interest . . . . . . . . . . . . . . . . . . . . 6 2.5. Points of interest . . . . . . . . . . . . . . . . . . . . 7
2.6. Reference point . . . . . . . . . . . . . . . . . . . . . 8 2.6. Reference point . . . . . . . . . . . . . . . . . . . . . 8
2.7. Vector . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.7. Vector . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.8. Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.8. Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3. Motivations . . . . . . . . . . . . . . . . . . . . . . . . . 9 3. Motivations . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1. Motivations for spatial metrics . . . . . . . . . . . . . 9 3.1. Motivations for spatial metrics . . . . . . . . . . . . . 9
3.2. Motivations for One-to-group metrics . . . . . . . . . . . 10 3.2. Motivations for One-to-group metrics . . . . . . . . . . . 10
3.3. Discussion on Group-to-one and Group-to-group metrics . . 11 3.3. Discussion on Group-to-one and Group-to-group metrics . . 11
4. Spatial vectors metrics definitions . . . . . . . . . . . . . 11 4. Spatial vectors metrics definitions . . . . . . . . . . . . . 11
4.1. A Definition for Spatial One-way Delay Vector . . . . . . 12 4.1. A Definition for Spatial One-way Delay Vector . . . . . . 12
4.2. A Definition for Spatial One-way Packet Loss Vector . . . 13 4.2. A Definition for Spatial One-way Packet Loss Vector . . . 13
4.3. A Definition for Spatial One-way Ipdv Vector . . . . . . . 15 4.3. A Definition for Spatial One-way Ipdv Vector . . . . . . . 15
4.4. Spatial Methodology . . . . . . . . . . . . . . . . . . . 17 4.4. Spatial Methodology . . . . . . . . . . . . . . . . . . . 16
5. Spatial Segments metrics definitions . . . . . . . . . . . . . 19 5. Spatial Segments metrics definitions . . . . . . . . . . . . . 18
5.1. A Definition of a sample of One-way Delay of a segment 5.1. A Definition of a sample of One-way Delay of a segment
of the path . . . . . . . . . . . . . . . . . . . . . . . 19 of the path . . . . . . . . . . . . . . . . . . . . . . . 18
5.2. A Definition of a sample of Packet Loss of a segment 5.2. A Definition of a sample of Packet Loss of a segment
of the path . . . . . . . . . . . . . . . . . . . . . . . 20 of the path . . . . . . . . . . . . . . . . . . . . . . . 20
5.3. A Definition of a sample of One-way Ipdv of a segment 5.3. A Definition of a sample of ipdv of a segment using
of the path . . . . . . . . . . . . . . . . . . . . . . . 23 the previous packet selection function . . . . . . . . . . 22
6. One-to-group metrics definitions . . . . . . . . . . . . . . . 23 5.4. A Definition of a sample of ipdv of a segment using
6.1. A Definition for one-to-group One-way Delay . . . . . . . 23 the minimum delay selection function . . . . . . . . . . . 24
6.2. A Definition for one-to-group One-way Packet Loss . . . . 24 6. One-to-group metrics definitions . . . . . . . . . . . . . . . 25
6.3. A Definition for one-to-group One-way Ipdv . . . . . . . . 25 6.1. A Definition for One-to-group One-way Delay . . . . . . . 26
7. One-to-Group Sample Statistics . . . . . . . . . . . . . . . . 26 6.2. A Definition for One-to-group One-way Packet Loss . . . . 26
7.1. Discussion on the Impact of packet loss on statistics . . 29 6.3. A Definition for One-to-group One-way Ipdv . . . . . . . . 27
7.2. General Metric Parameters . . . . . . . . . . . . . . . . 30 7. One-to-Group Sample Statistics . . . . . . . . . . . . . . . . 28
7.3. One-to-Group one-way Delay Statistics . . . . . . . . . . 31 7.1. Discussion on the Impact of packet loss on statistics . . 31
7.4. One-to-Group one-way Loss Statistics . . . . . . . . . . . 33 7.2. General Metric Parameters . . . . . . . . . . . . . . . . 32
7.5. One-to-Group one-way Delay Variation Statistics . . . . . 35 7.3. One-to-Group one-way Delay Statistics . . . . . . . . . . 33
8. Measurement Methods: Scaleability and Reporting . . . . . . . 35 7.4. One-to-Group one-way Loss Statistics . . . . . . . . . . . 36
8.1. Computation methods . . . . . . . . . . . . . . . . . . . 36 7.5. One-to-Group one-way Delay Variation Statistics . . . . . 38
8.2. Measurement . . . . . . . . . . . . . . . . . . . . . . . 37 8. Measurement Methods: Scalability and Reporting . . . . . . . . 38
8.3. Effect of Time and Space Aggregation Order on Stats . . . 37 8.1. Computation methods . . . . . . . . . . . . . . . . . . . 39
9. Manageability Considerations . . . . . . . . . . . . . . . . . 39 8.2. Measurement . . . . . . . . . . . . . . . . . . . . . . . 40
9.1. Reporting spatial metric . . . . . . . . . . . . . . . . . 39 8.3. Effect of Time and Space Aggregation Order on Stats . . . 40
9.2. Reporting One-to-group metric . . . . . . . . . . . . . . 40 9. Manageability Considerations . . . . . . . . . . . . . . . . . 42
9.3. Metric identification . . . . . . . . . . . . . . . . . . 41 9.1. Reporting spatial metric . . . . . . . . . . . . . . . . . 42
9.4. Reporting data model . . . . . . . . . . . . . . . . . . . 41 9.2. Reporting One-to-group metric . . . . . . . . . . . . . . 43
10. Open issues . . . . . . . . . . . . . . . . . . . . . . . . . 44 9.3. Metric identification . . . . . . . . . . . . . . . . . . 44
11. Security Considerations . . . . . . . . . . . . . . . . . . . 45 9.4. Reporting data model . . . . . . . . . . . . . . . . . . . 44
11.1. Spatial metrics . . . . . . . . . . . . . . . . . . . . . 45 10. Open issues . . . . . . . . . . . . . . . . . . . . . . . . . 47
11.2. one-to-group metric . . . . . . . . . . . . . . . . . . . 45 11. Security Considerations . . . . . . . . . . . . . . . . . . . 47
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 45 11.1. Spatial metrics . . . . . . . . . . . . . . . . . . . . . 48
13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 46 11.2. one-to-group metric . . . . . . . . . . . . . . . . . . . 48
14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 51 12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 48
14.1. Normative References . . . . . . . . . . . . . . . . . . . 51 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 48
14.2. Informative References . . . . . . . . . . . . . . . . . . 51 14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 52 14.1. Normative References . . . . . . . . . . . . . . . . . . . 54
Intellectual Property and Copyright Statements . . . . . . . . . . 54 14.2. Informative References . . . . . . . . . . . . . . . . . . 55
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 55
Intellectual Property and Copyright Statements . . . . . . . . . . 57
1. Introduction 1. Introduction
The IP Performance Metrics (IPPM) WG has defined a framework for The IP Performance Metrics (IPPM) WG has defined a framework for
metric definitions and end-to-end, or source to destination metric definitions and end-to-end, or source to destination
measurements: measurements:
o A general framework for defining performance metrics, described in o A general framework for defining performance metrics, described in
the Framework for IP Performance Metrics [RFC2330]; the Framework for IP Performance Metrics [RFC2330];
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be introduced to divide an end-to-end Type-P-One-way-Packet-Loss be introduced to divide an end-to-end Type-P-One-way-Packet-Loss
[RFC2680] in a spatial sequence of packet loss metrics. [RFC2680] in a spatial sequence of packet loss metrics.
o Using the Type-P-Spatial-One-way-Delay-Vector metric, a 'vector', o Using the Type-P-Spatial-One-way-Delay-Vector metric, a 'vector',
called Type-P-Spatial-One-way-ipdv-Vector, will be introduced to called Type-P-Spatial-One-way-ipdv-Vector, will be introduced to
divide an end-to-end Type-P-One-way-ipdv in a spatial sequence of divide an end-to-end Type-P-One-way-ipdv in a spatial sequence of
ipdv metrics. ipdv metrics.
o Using the Type-P-Spatial-One-way-Delay-Vector metric, a 'sample', o Using the Type-P-Spatial-One-way-Delay-Vector metric, a 'sample',
called Type-P-Segment-One-way-Delay-Stream, will be introduced to called Type-P-Segment-One-way-Delay-Stream, will be introduced to
collect a nested set of one-way delay metrics between the source, collect one-way delay metrics over time between two points of
intermediate points of interest, and the destination; interest of the path;
o Using the Type-P-Spatial-Packet-Loss-Vector metric, a 'sample', o Using the Type-P-Spatial-Packet-Loss-Vector metric, a 'sample',
called Type-P-Segment-Packet-Loss-Stream, will be introduced to called Type-P-Segment-Packet-Loss-Stream, will be introduced to
collect a nested set of packet loss metrics between the source, collect packet loss metrics over time between two points of
intermediate points of interest, and the destination; interest of the path;
o Using the Type-P-Spatial-ipdv-Vector metric, a 'sample', called o Using the Type-P-Spatial-One-way-Delay-Vector metric, a 'sample',
Type-P-Segment-ipdv-Stream, will be introduced to collect a nested called Type-P-Segment-ipdv-prev-Stream, will be introduced to
set of ipdv metrics between the source, intermediate points of compute ipdv metrics over time between two points of interest of
interest, and the destination; the path using the previous packet selection function;
o Using the Type-P-Spatial-One-way-Delay-Vector metric, a 'sample',
called Type-P-Segment-ipdv-min-Stream, will be introduced to
compute ipdv metrics over time between two points of interest of
the path using the shortest delay selection function;
Note that all these metrics are based on observations of packets Note that all these metrics are based on observations of packets
dedicated to testing, a process which is called Active measurement. dedicated to testing, a process which is called Active measurement.
Purely passive spatial measurement (for example, a spatial metric Purely passive spatial measurement (for example, a spatial metric
based on the observation of user traffic) is beyond the scope of this based on the observation of user traffic) is beyond the scope of this
document and the current IPPM charter. document and the current IPPM charter.
Next, this memo defines one-to-group metrics. Next, this memo defines one-to-group metrics.
o Using one test packet sent from one sender to a group of o Using one test packet sent from one sender to a group of
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where ha is the source and < hb, hc, ..., hn > are the destinations, where ha is the source and < hb, hc, ..., hn > are the destinations,
then measurements may be conducted between < ha, hb>, < ha, hc>, ..., then measurements may be conducted between < ha, hb>, < ha, hc>, ...,
<ha, hn >. <ha, hn >.
For the purposes of this memo (reflecting the scope of a single For the purposes of this memo (reflecting the scope of a single
source), the only multiparty metrics are one-to-group metrics. source), the only multiparty metrics are one-to-group metrics.
2.3. Spatial metric 2.3. Spatial metric
A metric is said to be spatial if one of the hosts (measurement A metric is said to be spatial if one of the hosts (measurement
collection points) involved is neither the source nor the destination collection points) involved is neither the source nor a destination
of the measured packet. of the measured packet.
2.4. One-to-group metric 2.4. One-to-group metric
A metric is said to be one-to-group if the measured packet is sent by A metric is said to be one-to-group if the measured packet is sent by
one source and (potentially) received by several destinations. Thus, one source and (potentially) received by several destinations. Thus,
the topology of the communication group can be viewed as a centre- the topology of the communication group can be viewed as a centre-
distributed or server-client topology with the source as the centre/ distributed or server-client topology with the source as the centre/
server in the topology. server in the topology.
2.5. Points of interest 2.5. Points of interest
Points of interest are the hosts* (as per RFC2330 definition, that Points of interest are the hosts* (as per RFC2330 definition, that
includes routing nodes) that are measurement collection points, a includes routing nodes) that are measurement collection points, a
sub-set of the set of hosts involved in the delivery of the packets sub-set of the set of hosts involved in the delivery of the packets
(in addition to the source itself). Note that the points of interest (in addition to the source itself). Note that the points of interest
are a possibly arbitrary sub-set of all the hosts involved in the are a possibly arbitrary sub-set of all the hosts involved in the
path. path.
Points of interest of One-to-group metrics are the intended Points of interest of one-to-group metrics are the intended
destination hosts for packets from the source (in addition to the destination hosts for packets from the source (in addition to the
source itself). source itself).
Src Recv Src Recv
`. ,-. `. ,-.
`. ,' `...... 1 `. ,' `...... 1
`. ; : `. ; :
`. ; : `. ; :
; :... 2 ; :... 2
| | | |
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calculations will be carried out. A centre/server in the calculations will be carried out. A centre/server in the
multimetrics measurement that is controlled by a network operator is multimetrics measurement that is controlled by a network operator is
a good example of a reference point, where measurement data can be a good example of a reference point, where measurement data can be
collected for further processing. However, the actual measurements collected for further processing. However, the actual measurements
have to be carried out at all points of interest. have to be carried out at all points of interest.
2.7. Vector 2.7. Vector
A Vector is a set of singletons, which are a set of results of the 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 observation of the behaviour of the same packet at different places
of a network at different times. For instance, if One-way delay of a network at different times. For instance, if one-way delay
singletons observed at N receivers for Packet P sent by the source singletons observed 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 Src are dT1, dT2,..., dTN, it can be say that a vector V with N
elements can be organized as {dT1, dT2,..., dTN}. The elements in elements can be organized as {dT1, dT2,..., dTN}. The elements in
one vector are singletons distinct with each other in terms of both one vector are singletons distinct with each other in terms of both
measurement point and sending time. Given the vector V as an measurement point and sending time. Given the vector V as an
example, the element dT1 is distinct from all others as the singleton example, the element dT1 is distinct from all others as the singleton
at receiver 1 in response to a packet sent from the source at time at receiver 1 in response to a packet sent from the source at time
T1. The complete Vector gives information over the dimension of T1. The complete Vector gives information over the dimension of
space. space.
2.8. Matrix 2.8. Matrix
Several vectors form a Matrix, which contains results observed in a Several vectors form a Matrix, which contains results observed in a
sampling interval at different places in a network at different time. sampling interval at different places in a network at different
For instance, given One-way delay vectors V1={dT11, dT12,..., dT1N}, times. For instance, given One-way delay vectors V1={dT11, dT12,...,
V2={dT21, dT22,..., dT2N},..., Vm={dTm1, dTm2,..., dTmN} for Packet dT1N}, V2={dT21, dT22,..., dT2N},..., Vm={dTm1, dTm2,..., dTmN} for
P1, P2,...,Pm, we can have a One-way delay Matrix {V1, V2,...,Vm}. Packet P1, P2,...,Pm, we can have a One-way delay Matrix {V1,
Additional to the information given by a Vector, a Matrix is more V2,...,Vm}. Additional to the information given by a Vector, a
powerful to present network performance in both space and time Matrix is more powerful to present network performance in both space
dimensions. It normally corresponds to a sample in simple point-to- and time dimensions. It normally corresponds to a sample in simple
point measurement. point-to-point measurement.
The relation among Singleton, Vector and Matrix can be shown in the The relation among Singleton, Vector and Matrix can be shown in the
following Figure 3. following Figure 3.
Point of Singleton Point of Singleton
interest / Samples interest / Samples
,----. ^ / ,----. ^ /
/ R1.....| / R1dT1 R1dT2 R1dT3 ... R3dTk \ / R1.....| / R1dT1 R1dT2 R1dT3 ... R3dTk \
/ \ | | | / \ | | |
; R2........| | R2dT1 R2dT2 R2dT3 ... R3dTk | ; R2........| | R2dT1 R2dT2 R2dT3 ... R3dTk |
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o Traffic engineering and troubleshooting applications benefit from o Traffic engineering and troubleshooting applications benefit from
spatial views of one-way delay and ipdv consumption, and spatial views of one-way delay and ipdv consumption, and
identification of the location of the lost of packets. identification of the location of the lost of packets.
o Monitoring the performance of a multicast tree composed of MPLS o Monitoring the performance of a multicast tree composed of MPLS
point-to-multipoint and inter-domain communication require spatial point-to-multipoint and inter-domain communication require spatial
decomposition of the one-way delay, ipdv, and packet loss. decomposition of the one-way delay, ipdv, and packet loss.
o Composition of metrics [I-D.ietf-ippm-spatial-composition] is o Composition of metrics [I-D.ietf-ippm-spatial-composition] is
needed to help measurement systems reach large scale coverage. needed to help measurement systems reach large scale coverage.
Spatial measure typically give the individual performance of an Spatial measures typically give the individual performance of an
intra domain segment and provide an elementary piece of intra domain segment and provide an elementary piece of
information needed to estimate interdomain performance based on information needed to estimate interdomain performance based on
composition of metrics. composition of metrics.
3.2. Motivations for One-to-group metrics 3.2. Motivations for One-to-group metrics
While the node-to-node based spatial measures can provide very useful While the node-to-node based spatial measures can provide very useful
data in the view of each connection, we also need measures to present data in the view of each connection, we also need measures to present
the performance of a multiparty communication topology. A simple the performance of a multiparty communication topology. A simple
one-way metric cannot completely describe the multiparty situation. one-way metric cannot completely describe the multiparty situation.
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o For designing and engineering multicast trees and MPLS point-to- o For designing and engineering multicast trees and MPLS point-to-
multipoint LSP; multipoint LSP;
o For evaluating and controlling of the quality of the multicast o For evaluating and controlling of the quality of the multicast
services; services;
o For controlling the performance of the inter domain multicast o For controlling the performance of the inter domain multicast
services; services;
o For presenting and evaluating the performance requirements for o For presenting and evaluating the performance requirements for
multiparty communications. multiparty communications and overlay multicast.
To understand the packet transfer performance between one source and To understand the packet transfer performance between one source and
any one receiver in the multiparty communication group, we need to any one receiver in the multiparty communication group, we need to
collect instantaneous end-to-end metrics, or singletons. It will collect instantaneous end-to-end metrics, or singletons. It will
give a very detailed insight into each branch of the multicast tree give a very detailed insight into each branch of the multicast tree
in terms of end-to-end absolute performance. This detail can provide in terms of end-to-end absolute performance. This detail can provide
clear and helpful information for engineers to identify the sub-path clear and helpful information for engineers to identify the sub-path
with problems in a complex multiparty routing tree. with problems in a complex multiparty routing tree.
The one-to-group metrics described in this memo introduce the The one-to-group metrics described in this memo introduce the
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the performance delivered to a group of users who are receiving the performance delivered to a group of users who are receiving
packets from the same source. The concept extends the "path" in the packets from the same source. The concept extends the "path" in the
one-way measurement to "path tree" to cover both one-to-one and one- one-way measurement to "path tree" to cover both one-to-one and one-
to-many communications. If applied to one-to-one communications, the to-many communications. If applied to one-to-one communications, the
one-to-group metrics provide exactly the same results as the one-to-group metrics provide exactly the same results as the
corresponding one-to-one metrics. corresponding one-to-one metrics.
3.3. Discussion on Group-to-one and Group-to-group metrics 3.3. Discussion on Group-to-one and Group-to-group metrics
We note that points of interest can also be selected to define We note that points of interest can also be selected to define
measurements on Group-to-one and Group-to-group topologies. These measurements on group-to-one and group-to-group topologies. These
topologies are currently beyond the scope of this memo, because they topologies are currently beyond the scope of this memo, because they
would involve multiple packets launched from different sources. would involve multiple packets launched from different sources.
However, we can give some clues here on these two cases. However, we can give some clues here on these two cases.
The measurements for group-to-one topology can be easily derived from The measurements for group-to-one topology can be easily derived from
the one-to-group measurement. The measurement point is the reference the one-to-group measurement. The measurement point is the reference
point that is acting as a receiver while all of clients/receivers point that is acting as a receiver while all of clients/receivers
defined for one-to-group measurement act as sources in this case. defined for one-to-group measurement act as sources in this case.
For the group-to-group connection topology, it is difficult to define For the group-to-group connection topology, it is difficult to define
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Spatial vectors metrics are based on the decomposition of standard Spatial vectors metrics are based on the decomposition of standard
end-to-end metrics defined by the IPPM WG in [RFC2679], [RFC2680], end-to-end metrics defined by the IPPM WG in [RFC2679], [RFC2680],
[RFC3393] and [RFC3432]. [RFC3393] and [RFC3432].
Definitions are coupled with the corresponding end-to-end metrics. Definitions are coupled with the corresponding end-to-end metrics.
Methodology specificities are common to all the vectors defined and Methodology specificities are common to all the vectors defined and
are consequently discussed in a common section. are consequently discussed in a common section.
4.1. A Definition for Spatial One-way Delay Vector 4.1. A Definition for Spatial One-way Delay Vector
This section is coupled with the definition of Type-P-One-way-Delay. This section is coupled with the definition of Type-P-One-way-Delay
When a parameter from section 3 of [RFC2679] is first used in this of the section 3 of [RFC2679]. When a parameter of this definitionis
section, it will be tagged with a trailing asterisk. 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 Sections 3.5 to 3.8 of [RFC2679] give requirements and applicability
statements for end-to-end one-way-delay measurements. They are statements for end-to-end one-way-delay measurements. They are
applicable to each point of interest Hi involved in the measure. applicable to each point of interest Hi involved in the measure.
Spatial one-way-delay measurement SHOULD be respectful of them, Spatial one-way-delay measurement SHOULD be respectful of them,
especially those related to methodology, clock, uncertainties and especially those related to methodology, clock, uncertainties and
reporting. reporting.
Following we adapt some of them and introduce points specific to
spatial measurement.
4.1.1. Metric Name 4.1.1. Metric Name
Type-P-Spatial-One-way-Delay-Vector Type-P-Spatial-One-way-Delay-Vector
4.1.2. Metric Parameters 4.1.2. Metric Parameters
o Src*, the IP address of the sender. o Src*, the IP address of the sender.
o Dst*, the IP address of the receiver. o Dst*, the IP address of the receiver.
o i, An integer if the list <1,2,...,n> which ordered the hosts in o i, An integer in the ordered list <1,2,...,n> of hosts in the
the path. path.
o Hi, A host* of the path digest. o Hi, A host* of the path digest.
o T*, a time, the sending (or initial observation) time for a o T*, a time, the sending (or initial observation) time for a
measured packet. measured packet.
o dT* a delay, the one-way delay for a measured packet. o dT*, a delay, the one-way delay for a measured packet.
o <dT1,..., dTn> a list of delay. o <dT1,..., dTn> a list of delay.
o P*, the specification of the packet type. o P*, the specification of the packet type.
o <H1, H2,..., Hn>, hosts path digest. o <H1, H2,..., Hn>, hosts path digest.
4.1.3. Metric Units 4.1.3. Metric Units
A sequence of times. The value of Type-P-Spatial-One-way-Delay-Vector is a sequence of
times.
4.1.4. Definition 4.1.4. Definition
Given a Type-P packet sent by the sender Src at wire-time (first bit) Given a Type-P packet sent by the sender Src at wire-time (first bit)
T to the receiver Dst in the path <H1, H2,..., Hn>. Given the T to the receiver Dst in the path <H1, H2,..., Hn>. Given the
sequence of values <T+dT1,T+dT2,...,T+dTn,T+dT> such that dT is the sequence of values <T+dT1,T+dT2,...,T+dTn,T+dT> such that dT is the
Type-P-One-way-Delay from Src to Dst and such that for each Hi of the Type-P-One-way-Delay from Src to Dst and such that for each Hi of the
path, T+dTi is either a real number corresponding to the wire-time path, T+dTi is either a real number corresponding to the wire-time
the packet passes (last bit received) Hi, or undefined if the packet the packet passes (last bit received) Hi, or undefined if the packet
never passes Hi. never passes Hi.
Type-P-Spatial-One-way-Delay-Vector metric is defined for the path Type-P-Spatial-One-way-Delay-Vector metric is defined for the path
<Src, H1, H2,..., Hn, Dst> as the sequence of values <Src, H1, H2,..., Hn, Dst> as the sequence of values
<T,dT1,dT2,...,dTn,dT>. <T,dT1,dT2,...,dTn,dT>.
4.1.5. Discussion 4.1.5. Discussion
Following are specific issues which may occur: Following are specific issues which may occur:
o the delay looks to decrease: dTi > DTi+1. This seem typically du o the delay looks to decrease: dTi > DTi+1. This may occur despite
to some clock synchronisation issue. This point is discussed in it does not make sense per definition:
the section 3.7.1. "Errors or uncertainties related to Clocks" of
of [RFC2679]. One consequence of these uncertainties is that
times of a measure at different hosts shall not be used to order
hosts on the path of a measure;
o The location of the point of interest in the device influences the * This is frequently due to some clock synchronization issue.
result. If the packet is not observed on the input interface the This point is discussed in the section 3.7.1. "Errors or
delay includes buffering time and consequently an uncertainty due uncertainties related to Clocks" of [RFC2679]. Consequently,
to the difference between 'wire time' and 'host time'; times of a measure at different hosts do not guaranty the
ordering of the hosts on the path of a measure.
* During some change of routes the order of 2 hosts may change on
the main path;
* The location of the point of interest in the device influences
the result. If the packet is not observed directly on the
input interface the delay includes buffering time and
consequently an uncertainty due to the difference between 'wire
time' and 'host time'
4.2. A Definition for Spatial One-way Packet Loss Vector 4.2. A Definition for Spatial One-way Packet Loss Vector
This section is coupled with the definition of Type-P-One-way-Packet- This section is coupled with the definition of Type-P-One-way-Packet-
Loss. Then when a parameter from the section 2 of [RFC2680] is first 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. used in this section, it will be tagged with a trailing asterisk.
Sections 2.5 to 2.8 of [RFC2680] give requirements and applicability Sections 2.5 to 2.8 of [RFC2680] give requirements and applicability
statements for end-to-end one-way-Packet-Loss measurements. They are statements for end-to-end one-way packet loss measurements. They are
applicable to each point of interest Hi involved in the measure. applicable to each point of interest Hi involved in the measure.
Spatial packet loss measurement SHOULD be respectful of them, Spatial packet loss measurement SHOULD be respectful of them,
especially those related to methodology, clock, uncertainties and especially those related to methodology, clock, uncertainties and
reporting. reporting.
Following we define the spatial metric, then we adapt some of the Following we define the spatial metric, then we adapt some of the
points above and introduce points specific to spatial measurement. points above and introduce points specific to spatial measurement.
4.2.1. Metric Name 4.2.1. Metric Name
Type-P-Spatial-One-way-Packet-Loss-Vector Type-P-Spatial-One-way-Packet-Loss-Vector
4.2.2. Metric Parameters 4.2.2. Metric Parameters
+ Src*, the IP address of the sender. o Src*, the IP address of the sender.
+ Dst*, the IP address of the receiver. o Dst*, the IP address of the receiver.
+ i, An integer which ordered the hosts in the path. o i, an integer which ordered the hosts in the path.
+ Hi, exchange points of the path digest. o Hi, points of interests of the path digest.
+ T*, a time, the sending (or initial observation) time for o T*, a time, the sending time for a measured packet.
a measured packet.
+ dT1,..., dTn, dT, a list of delay. o <dT1,..., dTn, dT>, a list of delay.
+ P*, the specification of the packet type. o P*, the specification of the packet type.
+ <SH1, H2,..., Hn>, hosts path digest. o <H1, H2,..., Hn>, hosts path digest.
+ B1, B2, ..., Bi, ..., Bn, a list of Boolean values. o <L1, L2, ...,Ln>, a list of Boolean values.
4.2.3. Metric Units 4.2.3. Metric Units
A sequence of Boolean values. The value of Type-P-Spatial-One-way-Packet-Loss-Vector is a sequence
of Boolean values.
4.2.4. Definition 4.2.4. Definition
Given a Type-P packet sent by the sender Src at time T to the Given a Type-P packet sent by the sender Src at time T to the
receiver Dst in the path <H1, H2, ..., Hn>. Given the sequence of receiver Dst in the path <H1, H2, ..., Hn>. Given the sequence of
times <T+dT1,T+dT2,...,T+dTn,T+dT> the packet passes <H1, H2 ..., Hn, times <T+dT1,T+dT2,...,T+dTn> the packet passes in <H1, H2 ..., Hn>,
Dst>, we define Type-P-One-way-Packet-Lost-Vector metric as the sequence of
values <L1, L2, ..., Ln> such that for each Hi of the path, a value
Type-P-One-way-Packet-Lost-Vector metric is defined as the sequence of 0 for Li means that dTi is a finite value, and a value of 1 means
of values <B1, B2, ..., Bn> such that for each Hi of the path, a that dTi is undefined.
value of Bi of 0 means that dTi is a finite value, and a value of 1
means that dTi is undefined.
4.2.5. Discussion 4.2.5. Discussion
Following are specific issues which may occur: Following are specific issues which may occur:
o the result includes the sequence 1,0. This case means that the o The result includes the sequence 1,0. This may occur under
packet was seen by a host but not by it successor on the path; specific situations:
The location of the point of interest in the device influences the * During some change of routes a packet may be seen by a host but
result: not by it successor on the main path;
o Even if the packet is received by a host, it may be not observed * A packet may not be observed in a host due to some buffer or
by the point of interest located after a buffer; CPU overflow in the point of interest;
4.3. A Definition for Spatial One-way Ipdv Vector 4.3. A Definition for Spatial One-way Ipdv Vector
This section uses parameters from the definition of Type-P-One-way- This section uses parameters from the definition of Type-P-One-way-
ipdv. When a parameter from section 2 of [RFC3393] is first used in ipdv. When a parameter from section 2 of [RFC3393] is first used in
this section, it will be tagged with a trailing asterisk. this section, it will be tagged with a trailing asterisk.
Following we adapt some of them and introduce points specific which In the following we adapt some of them and introduce points specific
are to spatial measurement. to spatial measurement.
4.3.1. Metric Name 4.3.1. Metric Name
Type-P-Spatial-One-way-ipdv-Vector Type-P-Spatial-One-way-ipdv-Vector
4.3.2. Metric Parameters 4.3.2. Metric Parameters
+ Src*, the IP address of the sender. o Src*, the IP address of the sender.
+ Dst*, the IP address of the receiver. o Dst*, the IP address of the receiver.
+ i, An integer which ordered the hosts in the path. o i, An integer in the ordered list <1,2,...,n> of hosts in the
path.
+ Hi, exchange points of the path digest. o Hi, A host* of the path digest.
+ T1*, the time the first packet was sent. o T1*, a time, the sending time for a first measured packet.
+ T2*, the time the second packet was sent. o T2*, a time, the sending time for a second measured packet.
+ P, the specification of the packet type. o dT*, a delay, the one-way delay for a measured packet.
+ P1, the first packet sent at time T1. o P*, the specification of the packets type.
+ P2, the second packet sent at time T2. o P1, the first packet sent at time T1.
+ <H1, H2,..., Hn>, host path digest. o P2, the second packet sent at time T2.
+ <T1,dT1.1, dT1.2,..., dT1.n,dT1>, o <H1, H2,..., Hn>, hosts path digest.
the Type-P-Spatial-One-way-Delay-Vector for packet sent at
time T1;
+ <T2,dT2.1, dT2.2,..., dT2.n,dT2>, o <T1,dT1.1, dT1.2,..., dT1.n,dT1>, the Type-P-Spatial-One-way-
the Type-P-Spatial-One-way-Delay-Vector for packet sent at Delay-Vector for packet sent at time T1.
time T2;
+ L*, a packet length in bits. The packets of a Type P o <T2,dT2.1, dT2.2,..., dT2.n,dT2>, the Type-P-Spatial-One-way-
packet stream from which the Delay-Vector for packet sent at time T2.
Type-P-Spatial-One-way-Delay-Vector metric is taken MUST
all be of the same length. o L*, a packet length in bits. The packets of a Type P packet
stream from which the Type-P-Spatial-One-way-Delay-Vector metric
is taken MUST all be of the same length.
4.3.3. Metric Units 4.3.3. Metric Units
A sequence of times. The value of Type-P-Spatial-One-way-ipdv-Vector is a sequence of
times.
4.3.4. Definition 4.3.4. Definition
Given the Type-P packet having the size L and sent by the sender Src Given P1 the Type-P packet sent by the sender Src at wire-time (first
at wire-time (first bit) T1 to the receiver Dst in the path <H1, bit) T1 to the receiver Dst and <T1, dT1.1, dT1.2,..., dT1.n, dT1>
H2,..., Hn>. its Type-P-Spatial-One-way-Delay-Vector over the path <H1, H2,...,
Hn>.
Given the Type-P packet having the size L and sent by the sender Src
at wire-time (first bit) T2 to the receiver Dst in the same path.
Given the Type-P-Spatial-One-way-Delay-Vector <T1,dT1.1, dT1.2,...,
dT1,n,dT1> of the packet P1.
Given the Type-P-Spatial-One-way-Delay-Vector <T2,dT2.1, dT2.2,..., Given P2 the Type-P packet sent by the sender Src at wire-time (first
dT2,n,dT2> of the packet P2. bit) T2 to the receiver Dst and <T2, dT2.1, dT2.2,..., dT2.n, dT2>
its Type-P-Spatial-One-way-Delay-Vector over the same path.
Type-P-Spatial-One-way-ipdv-Vector metric is defined as the sequence Type-P-Spatial-One-way-ipdv-Vector metric is defined as the sequence
of values <T2-T1,dT2.1-dT1.1,dT2.2-dT1.2,...,dT2.n-dT1.n,dT2-dT1> of values <T2-T1, dT2.1-dT1.1, dT2.2-dT1.2 ,..., dT2.n-dT1.n, dT2-
Such that for each Hi of the path <H1, H2,..., Hn>, dT2.i-dT1.i is dT1> such that for each Hi of the path <H1, H2,..., Hn>, dT2.i-dT1.i
either a real number if the packets P1 and P2 passes Hi at wire-time is either a real number if the packets P1 and P2 passe Hi at wire-
(last bit) dT1.i, respectively dT2.i, or undefined if at least one of time (last bit) dT1.i, respectively dT2.i, or undefined if at least
them never passes Hi. T2-T1 is the inter-packet emission interval one of them never passes Hi. T2-T1 is the inter-packet emission
and dT2-dT1 is ddT* the Type-P-One-way-ipdv at T1,T2*. interval and dT2-dT1 is ddT* the Type-P-One-way-ipdv at T1,T2*.
4.4. Spatial Methodology 4.4. Spatial Methodology
Methodology, reporting and uncertainties points specified in section Methodology, reporting and uncertainties points specified in section
3 of [RFC2679][RFC2679] applies to each point of interest Hi 3 of [RFC2679] applies to each point of interest Hi measuring a
measuring a element of a spatial delay vector. element of a spatial delay vector.
Methodology, reporting and uncertainties points specified in section Methodology, reporting and uncertainties points specified in section
2 of [RFC2680][RFC2680] applies to each point of interest Hi 2 of [RFC2680] applies to each point of interest Hi measuring a
measuring a element of a spatial packet loss vector. element of a spatial packet loss vector.
Sections 3.5 to 3.7 of [RFC3393] give requirements and applicability Sections 3.5 to 3.7 of [RFC3393] give requirements and applicability
statements for end-to-end One-way ipdv measurements. They are statements for end-to-end One-way ipdv measurements. They are
applicable to each point of interest Hi involved in the measure. applicable to each point of interest Hi involved in the measure.
Spatial One-way ipdv measurement SHOULD be respectful of methodology, Spatial One-way ipdv measurement SHOULD be respectful of methodology,
clock, uncertainties and reporting aspects given in this section. clock, uncertainties and reporting aspects given in this section.
Generally, for a given Type-P of length L, in a given Hi, the Generally, for a given Type-P of length L, in a given Hi, the
methodology for spatial vector metrics would proceed as follows: methodology for spatial vector metrics may proceed as follows:
o At each Hi, points of interest prepare to capture the packet sent o At each Hi, points of interest prepare to capture the packet sent
a time T, take a timestamp Ti', determine the internal delay a time T, take a timestamp Ti', determine the internal delay
correction dTi' (See section 3.7.1. "Errors or uncertainties correction dTi' (See section 3.7.1. "Errors or uncertainties
related to Clocks" of [RFC2679]), related to Clocks" of [RFC2679]),
o Each Hi extracts the path ordering information from the packet o Each Hi extracts the path ordering information from the packet
(e.g. time-to-live); (e.g. time-to-live);
o Each Hi compute the wiretime from Src to Hi: Ti = Ti' - dTi'. o Each Hi compute the wiretime from Src to Hi: Ti = Ti' - dTi'.
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related to Clocks" of [RFC2679]), related to Clocks" of [RFC2679]),
o Each Hi extracts the path ordering information from the packet o Each Hi extracts the path ordering information from the packet
(e.g. time-to-live); (e.g. time-to-live);
o Each Hi compute the wiretime from Src to Hi: Ti = Ti' - dTi'. o Each Hi compute the wiretime from Src to Hi: Ti = Ti' - dTi'.
This arrival time is undefined (infinite) if the packet is not This arrival time is undefined (infinite) if the packet is not
detected after the 'loss threshold' duration; detected after the 'loss threshold' duration;
o Each Hi extracts the timestamp T from the packet; o Each Hi extracts the timestamp T from the packet;
o Each Hi computes the one-way-delay from Src to Hi: dTi = Ti - T; o Each Hi computes the one-way-delay from Src to Hi: dTi = Ti - T;
o The reference point gathers the result and time-to-live of each Hi o The reference point gathers the result of each Hi and order them
and order them according to the path to build the Type-P-Spatial- according to the path ordering information received to build the
One-way-Delay-Vector metric <T,dT1,dT2,...,dTn,dT> over the path type-P spatial one-way vector (e.g. Type-P-Spatial-One-way-Delay-
<Src,H1, H2,..., Hn, Dst>. Vector metric <T, dT1, dT2,..., dTn, dT> ) over the path <Src, H1,
H2,..., Hn, Dst> at time T.
4.4.1. Loss threshold 4.4.1. Loss threshold
Loss threshold is the centrality of any methodology because it Loss threshold is the centrality of any methodology because it
determines the presence the packet in the measurement process of the determines the presence the packet in the measurement process of the
point of interest and consequently determines any ground truth metric point of interest and consequently determines any ground truth metric
result. It determines the presence of an effective delay, and bias result. It determines the presence of an effective delay, and bias
the measure of ipdv, of packet loss and of the statistics. the measure of ipdv, of packet loss and of the statistics.
This is consistent for end-to-end but impacts spatial measure: This is consistent for end-to-end but impacts spatial measure:
depending on the consistency of the Loss threshold among the points depending on the consistency of the loss threshold among the points
of interest, a packet may be considered loss a one host but present of interest, a packet may be considered loss a one host but present
in another one, or may be observed by the last host (last hop) of the in another one, or may be observed by the last host (last hop) of the
path but considered lost by Dst. The analysis of such results is not path but considered lost by Dst. The analysis of such results is not
deterministic: has the path change? Does the packet arrive at deterministic: Has the path change? Does the packet arrive at
destination or was it lost during the last mile? The same applies, destination or was it lost during the last mile? The same applies,
of course, for one-way-delay measures: a delay measured may be of course, for one-way-delay measures: a delay measured may be
infinite at one host but a real value in another one, or may be infinite at one host but a real value in another one, or may be
measured as a real value by the last host of the path but observed as measured as a real value by the last host of the path but observed as
infinite by Dst. The Loss threshold should be set up with the same infinite by Dst. The loss threshold should be set up with the same
value in each host of the path and in the destination. The Loss value in each host of the path and in the destination. The loss
threshold must be systematically reported to permit careful threshold must be systematically reported to permit careful
introspection and to avoid the introduction of any contradiction in introspection and to avoid the introduction of any contradiction in
the statistic computation process. the statistic computation process.
4.4.2. Host Path Digest 4.4.2. Host Path Digest
The methodology given above adds the order of the points of interest The methodology given above relies on the order of the points of
over the path to [RFC2679] one's. interest over the path to [RFC2679] one's.
A perfect Host Path Digest (hum! of cource from the measurement point
of view only, that is, corresponding to the real path the test packet
experimented) may include several times several hosts:
o <Ha,..., Ha> coresponds to a loop in the path; A test packets may cross several times the same host resulting in the
repetition of one or several hosts in the Path Digest.
o <Ha,..,Hb,..., Ha,...,Hb> coresponds to a loop in the path which As an example. This occurs typically during rerouting phases which
may occurs during rerouting phases; introduce temporary micro loops. During such an event the host path
digest for a packet crossing Ha and Hb may include the pattern <Hb,
Ha, Hb, Ha, Hb> meaning that Ha ended the computation of the new path
before Hb and that the initial path wath from Ha to Hb and that the
new path is from Hb to Ha.
These cases MUST be identified before statistics computation to avoid Consequently, duplication of hosts in the Path Digest of a vectors
corrupted results' production. This applies especially to the MUST be identified before statistics computation to avoid corrupted
measure of segments which are build from results of a measure of a results' production.
vector metric.
5. Spatial Segments metrics definitions 5. Spatial Segments metrics definitions
This section defines samples to measure a sequence of delays, a This section defines samples to measure the performance of a segment
sequence of lost and a sequence of ipdv between 2 hosts of the path, of a path over time. Definitions rely on matrix of the spatial
a segment. Singletons are taken from segments of vectors defined vector metrics defined above.
above.
Firstly it defines a sample of one-way delay, Type-P-Segment-One-way-
Delay-Stream, and a sample of packet loss, Type-P-segment-Packet-
loss-Stream.
Then it defines 2 different samples of ipdv. The first metric, Type-
P-Segment-One-way-ipdv-prev-Stream, uses the previous packet as the
selection function. The second metric, Type-P-Segment-One-way-ipdv-
min-Stream, uses the minimum delay as the selection.
5.1. A Definition of a sample of One-way Delay of a segment of the path 5.1. A Definition of a sample of One-way Delay of a segment of the path
This metric defines a sample of One-way delays between a pair of This metric defines a sample of One-way delays over time between a
hosts of a path. pair of hosts of a path.
As its semantic is very close to the metric Type-P-Packet-loss-Stream
defined in section 4 of [RFC2679], sections 4.5 to 4.8 of [RFC2679]
are part of the current definition.
5.1.1. Metric Name 5.1.1. Metric Name
Type-P-Segment-One-way-Delay-Stream Type-P-Segment-One-way-Delay-Stream
5.1.2. Metric Parameters 5.1.2. Metric Parameters
+ Src*, the IP address of the sender. o Src*, the IP address of the sender.
+ Dst*, the IP address of the receiver. o Dst*, the IP address of the receiver.
+ P*, the specification of the packet type; o P*, the specification of the packet type.
+ i, An integer which orders exchange points in the path. o i, an integer in the ordered list <1,2,...,n> of hosts in the
path.
+ k, An integer which orders the packets sent. o k, an integer which orders the packets sent.
+ Hi, a host of the path digest; o a and b, 2 integers where b > a.
+ <H1, H2,..., Hn>, host path digest. o Hi, a host* of the path digest.
+ Ha, a host of the path digest different from Dst and Hb; o <H1,..., Ha, ..., Hb, ...., Hn>, hosts path digest.
+ Hb, a host of the path digest different from Src and Ha. o <T1, T2, ..., Tm>, a list of times.
Hb order in the path must greater that Ha;
+ <T1, ..., Tk>, a list of time ordered by k; 5.1.3. Metric Units
+ dT1,..., dTn a list of delay; The value of a Type-P-Segment-One-way-Delay-Stream is a pair of
5.1.3. Metric Units list of times <T1, T2, ..., Tm>;
A sequence of delay sequence of delays.
5.1.4. Definition 5.1.4. Definition
Given 2 hosts Ha and Hb of the path <Src, H1, H2,..., Hn, Dst>, given Given 2 hosts, Ha and Hb, of the path <H1, H2,..., Ha, ..., Hb, ...,
a flow of packets of Type-P sent from Src to Dst at the times T1, Hn>, given the matrix of Type-P-Spatial-One-way-Delay-Vector for the
T2... Tn. At each of these times, we obtain a Type-P-Spatial-One- packets sent from Src to Dst at times <T1, T2, ..., Tm-1, Tm> :
way-Delay-Vector <T1,dT1.a, ..., dT1.b,...,, dT1.n,dT1>. We define
the value of the sample Type-P-segment-One-way-Delay-Stream as the
sequence made up of the delays dTk.b - dTk.a. dTk.a is the delay
between Src and Ha. dTk.b is the delay between Src and Hb. 'dTk.b -
dTk.a' is the one-way delay experienced by the packet sent by Src at
the time Tk when going from Ha to Hb.
5.1.5. Discussion <T1, dT1.1, dT1.2, ..., dT1.a, ..., dT1.b,..., dT1.n, dT1>;
Following are specific issues which may occur: <T2, dT2.1, dT2.2, ..., dT2.a, ..., dT2.b,..., dT2.n, dT2>;
o When a is Src <Tk,dTk.b - dTk.a> is the measure of the first hop. ...
o When b is Dst <Tk,dTk.b - dTk.a> is the measure of the last hop. <Tm, dTm.1, dTm.2, ..., dTm.a, ..., dTm.b,..., dTm.n, dTm>.
We define the sample Type-P-segment-One-way-Delay-Stream as the
sequence <dT1.ab, dT2.ab, ..., dTk.ab, ..., dTm.ab> such that for
each time Tk, 'dTk.ab' is either the real number 'dTk.b - dTk.a' if
the packet send a time Tk passes Ha and Hb or undefined if this
packet never passes Ha or (inclusive) never passes Hb.
5.1.5. Discussion
Following are specific issues which may occur:
o the delay looks to decrease: dTi > DTi+1: o the delay looks to decrease: dTi > DTi+1:
* This is typically du to clock synchronisation issue. this point * This is typically due to clock synchronization issue. this
is discussed in the section 3.7.1. "Errors or uncertainties point is discussed in the section 3.7.1. "Errors or
related to Clocks" of of [RFC2679]; uncertainties related to Clocks" of of [RFC2679];
* This may occurs too when the clock resolution of one probe is * This may occurs too when the clock resolution of one probe is
bigger than the minimum delay of a path. As an example this bigger than the minimum delay of a path. As an example this
happen when measuring the delay of a path which is 500 km long happen when measuring the delay of a path which is 500 km long
with one probe synchronized using NTP having a clock resolution with one probe synchronized using NTP having a clock resolution
of 8ms. of 8ms.
o The location of the point of interest in the device influences the The metric can not be performed on < T1 , T2, ..., Tm-1, Tm> in the
result. If the packet is not observed on the input interface the following cases:
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 Ha or Hb disappears from the path due to some change of routes;
o The order of Ha and Hb changes in the path;
5.2. A Definition of a sample of Packet Loss of a segment of the path 5.2. A Definition of a sample of Packet Loss of a segment of the path
This metric defines a sample of Packet lost between a pair of hosts This metric defines a sample of packet lost over time between a pair
of a path. of hosts of a path. As its semantic is very close to the metric
Type-P-Packet-loss-Stream defined in section 3 of [RFC2680], sections
3.5 to 3.8 of [RFC2680] are part of the current definition.
5.2.1. Metric Name 5.2.1. Metric Name
Type-P-segment-Packet-loss-Stream Type-P-segment-Packet-loss-Stream
5.2.2. Metric Parameters 5.2.2. Metric Parameters
+ Src*, the IP address of the sender. o Src*, the IP address of the sender.
+ Dst*, the IP address of the receiver.
+ P*, the specification of the packet type. o Dst*, the IP address of the receiver.
+ k, An integer which orders the packets sent. o P*, the specification of the packet type.
+ n, An integer which orders the hosts on the path. o k, an integer which orders the packets sent.
+ <H1, H2,..., Hn>, hosts path digest. o n, an integer which orders the hosts on the path.
+ Ha, a host of the path digest different from Dst and Hb; o a and b, 2 integers where b > a.
+ Hb, a host of the path digest different from Src and Ha. o <H1, H2, ..., Ha, ..., Hb, ...,Hn>, hosts path digest.
Hb order in the path must greater that Ha;
+ Hi, exchange points of the path digest. o Hi, exchange points of the path digest.
+ <B1, B2, ..., Bn> a list of bits. o <T1, T2, ..., Tm>, a list of times.
+ <L1, L2, ..., Ln> a list of integers. o <L1, L2, ..., Ln> a list of boolean values.
5.2.3. Metric Units 5.2.3. Metric Units
A sequence of integers <L1, L2,..., Lk> The value of a Type-P-segment-Packet-loss-Stream is a pair of
The list of times <T1, T2, ..., Tm>;
a sequence of booleans.
5.2.4. Definition 5.2.4. Definition
Given 2 hosts Ha and Hb of the path <Src, H1, H2,..., Hn, Dst>, given Given 2 hosts, Ha and Hb, of the path <H1, H2,..., Ha, ..., Hb, ...,
a flow of packets of Type-P sent from Src to Dst at the times T1, Hn>, given the matrix of Type-P-Spatial-Packet-loss-Vector for the
T2... Tn. At each of these times, we obtain a Type-P-Spatial- packets sent from Src to Dst at times <T1, T2, ..., Tm-1, Tm> :
Packet-Lost-Vector <B1.1, B1.2,..., B1.n>. We define the value of
the sample Type-P-segment-Packet-Lost-Stream between Ha and Hb as the
sequence made up of the integer <L1, L2,..., Lk> such that for each
Tk:
o a value of Lk of 0 means that Bk.a has a value of 0 (observed) and <L1.1, L1.2,..., L1.a, ..., L1.b, ..., L1.n, L>,
that Bk.b have a value of 0 (observed);
o a value of Lk of 1 means that Bk.a has a value of 0 (observed) and
that Bk.b have a value of 1 (not observed);
o a value of Lk of 2 means that Bk.a has a value of 1 (not observed) <L2.1, L2.2,..., L2.a, ..., L2.b, ..., L2.n, L>,
and that Bk.b have a value of 0 (observed);
o a value of Lk of 3 means that Bk.a has a value of 1 (not observed) ...,
and that Bk.b have a value of 1 (not observed).
5.2.5. Discussion <Lm.1, Lm.2,..., Lma, ..., Lm.b, ..., Lm.n, L>.
The semantic of a Type-P-segment-Packet-loss-Stream is similar to the We define the value of the sample Type-P-segment-Packet-Lost-Stream
one of Type-P-Packet-loss-Stream: from Ha to Hb as the sequence of booleans <L1.ab, L2.ab,..., Lk.ab,
..., Lm.ab> such that for each Tk:
o a value of 0 means that the packet was observed by Ha (similar to o A value of Lk of 0 means that Ha and Hb observed the packet sent
'send by Src') and not observed by Hb ( similar to 'not received at time Tk (Lk.a and Lk.b have a value of 0);
by Dst');
o a value of 1 means that it was observed by Ha (similar to 'send by o A value of Lk of 1 means that Ha observed the packet sent at time
Src') and observed by Hb ( similar to 'received by Dst'). Tk (Lk.a has a value of 0) and that Hb did not observed the packet
sent at time Tk (Lk.b have a value of 1);
o The value of Lk is undefined when Neither Ha or Hb observe the
packet;
This definition of Type-P-segment-Packet-loss-Stream is similar to 5.2.5. Discussion
the Type-P-Packet-loss-Stream defined in [RFC2680] excepted that in a
Type-P-segment-Packet-loss-Stream the rules of the point of interests
Ha and Hb are symetrical: The asumption that a set of packets are
going from Ha to Hb does not apply to Type-P-segment-Packet-loss-
Stream because as the host path digest is dynamic each packet has its
own host path digest.
Making the asumption that the host path digest of a Type-P-spatial- Unlike Type-P-Packet-loss-Stream, Type-P-Segment-Packet-loss-Stream
Packet-loss-vector does not change and that the set of (Hk, Hk+1) relies on the stability of the host path digest. The metric can not
tuples is mostly stable over time lead to unusable results and to the be performed on < T1 , T2, ..., Tm-1, Tm> in the following cases:
introduction of mistakes in the metrics aggregation processes. The
right approach consists in carefully scrutening the path ordering
information to build sample with elements of vectors sharing the same
properties in term of Ha and Hb and 'Ha to Hb'. So a measure of
Type-P-spatial-Packet-loss-vector differs from a Type-P-Packet-loss
one in that it produces different samples of packet loss over time.
The semantic of a Type-P-segment-Packet-loss-Stream defines 2 new o Ha or Hb disappears from the path due to some change of routes;
results:
o A value of Lk of 2 (1,0) corresponds to a mistake in the ordering o the order of Ha and Hb changes in the path;
of Ha and Hb over the path coming either from the configuration
(asumption on the path) or from the processing of the vectors: bad
scrutening of the path ordering information, or some other mistake
in the measure or the reporting. It is not in the scope of this
document to go in further details which are mostly implementation
dependent. This value MUST not be used to compute packet lost
statistics.
o A value of Lk of 3 (1,1) corresponds to a lost of the packet in o Lk.a or Lk.b is undefined;
upper segment of the path.
5.3. A Definition of a sample of One-way Ipdv of a segment of the path o Lk.a has the value 1 (not observed) and Lk.b has the value 0
(observed);
This metric defines a sample of ipdv between a pair of hosts of a o L has the value 0 (the packet was received by Dst) and Lk.ab has
path. the value 1 (the packet was lost between Ha and Hb).
Editor note: work in progress 5.3. A Definition of a sample of ipdv of a segment using the previous
packet selection function
This metric defines a sample of ipdv [RFC3393] over time between a
pair of hosts using the previous packet as the selection function.
5.3.1. Metric Name 5.3.1. Metric Name
Type-P-Segment-Ipdv-Stream Type-P-Segment-One-way-ipdv-prev-Stream
5.3.2. Metric Parameters 5.3.2. Metric Parameters
o Src*, the IP address of the sender.
o Dst*, the IP address of the receiver.
o P*, the specification of the packet type.
o k, an integer which orders the packets sent.
o n, an integer which orders the hosts on the path.
o a and b, 2 integers where b > a.
o <H1, H2, ..., Ha, ..., Hb, ...,Hn>, the hosts path digest.
o <T1, T2, ..., Tm-1, Tm>, a list of times.
o <Tk, dTk.1, dTk.2, ..., dTk.a, ..., dTk.b,..., dTk.n, dTk>, a
Type-P-Spatial-One-way-Delay-Vector.
5.3.3. Metric Units 5.3.3. Metric Units
The value of a Type-P-Segment-One-way-ipdv-prev-Stream is a pair of:
The list of <T1, T2, ..., Tm-1, Tm>;
A list of pairs of interval of times and delays;
5.3.4. Definition 5.3.4. Definition
Given 2 hosts, Ha and Hb, of the path <H1, H2,..., Ha, ..., Hb, ...,
Hn>, given the matrix of Type-P-Spatial-One-way-Delay-Vector for the
packets sent from Src to Dst at times <T1, T2, ..., Tm-1, Tm> :
<T1, dT1.1, dT1.2, ..., dT1.a, ..., dT1.b,..., dT1.n, dT1>,
<T2, dT2.1, dT2.2, ..., dT2.a, ..., dT2.b,..., dT2.n, dT2>,
...
<Tm, dTm.1, dTm.2, ..., dTm.a, ..., dTm.b,..., dTm.n, dTm>.
We define the Type-P-Segment-One-way-ipdv-prev-Stream as the sequence
of pair of packet intervals and delay variations <(dT2_1.a , dT2.ab -
dT1.ab) ,..., (dTk_k-1.a, dTk.ab - dTk-1.ab), ..., (dTm_m-1.a, dTm.ab
- dTm-1.ab)> such that for each Tk:
o dTk_k-1.a is either undefined if the delay dTk.a or the delay
dTk-1.a is undefined, or the interval of time, 'dTk.a - dTk-1.a',
between the 2 packets at Ha;
o dTk_k-1.ab, is either undefined if one of the delays dTk.b, dTk.a,
dTk-1.b or dTk-1.a is undefined, or , (dTk.b - dTk.a) - (dTk-1.b -
dTk-1.a), the delay variation from Ha to Hb between the 2 packets
sent at time Tk and Tk-1.
5.3.5. Discussion 5.3.5. Discussion
This metric belongs to the family of inter packet delay variation
metrics (IPDV in upper case) which results can be extremely sensitive
to the inter-packet interval.
The inter-packet interval of a end-to-end IPDV metric is under the
control of the ingress point of interest which corresponds exactly to
the Source of the packet. Unlikely, the inter-packet interval of a
segment IPDV metric is not under the control the ingress point of
interest of the measure, Ha. However, the interval will vary if
there is delay variation between the Source and Ha. Therefore, the
actual inter-packet interval must be known at Ha in order to fully
comprehend the delay variation between Ha and Hb.
5.4. A Definition of a sample of ipdv of a segment using the minimum
delay selection function
This metric defines a sample of ipdv [RFC3393] over time between a
pair of hosts of a path using the shortest delay as the selection
function.
5.4.1. Metric Name
Type-P-Segment-One-way-ipdv-min-Stream
5.4.2. Metric Parameters
o Src*, the IP address of the sender.
o Dst*, the IP address of the receiver.
o P*, the specification of the packet type.
o k, an integer which orders the packets sent.
o i, an integer which identifies a packet sent.
o n, an integer which orders the hosts on the path.
o a and b, 2 integers where b > a.
o <H1, H2, ..., Ha, ..., Hb, ...,Hn>, the hosts path digest.
o <T1, T2, ..., Tm-1, Tm>, a list of times.
o <Tk, dTk.1, dTk.2, ..., dTk.a, ..., dTk.b,..., dTk.n, dTk>, a
Type-P-Spatial-One-way-Delay-Vector.
5.4.3. Metric Units
The value of a Type-P-Segment-One-way-ipdv-min-Stream is a pair of:
The list of <T1, T2, ..., Tm-1, Tm>;
A list of times;
5.4.4. Definition
Given 2 hosts, Ha and Hb, of the path <H1, H2,..., Ha, ..., Hb, ...,
Hn>, given the matrix of Type-P-Spatial-One-way-Delay-Vector for the
packets sent from Src to Dst at times <T1, T2, ..., Tm-1, Tm> :
<T1, dT1.1, dT1.2, ..., dT1.a, ..., dT1.b,..., dT1.n, dT1>,
<T2, dT2.1, dT2.2, ..., dT2.a, ..., dT2.b,..., dT2.n, dT2>,
...
<Tm, dTm.1, dTm.2, ..., dTm.a, ..., dTm.b,..., dTm.n, dTm>.
We define the Type-P-Segment-One-way-ipdv-min-Stream as the sequence
of times <dT1.ab - min(dTi.ab) ,..., dTk.ab - min(dTi.ab), ...,
dTm.ab - min(dTi.ab)> such that:
min(dTi.ab) is the minimum value of the tuples (dTk.b - dTk.a);
for each time Tk, dTk.ab is undefined if dTk.a or (inclusive)
dTk.b is undefined, or the real number (dTk.b - dTk.a).
5.4.5. Discussion
This metric belongs to the family of packet delay variation metrics
(PDV). PDV distributions are less sensitive to inter-packet interval
variations than IPDV results.
In principle, the PDV distribution reflects the variation over many
different inter-packet intervals, from the smallest inter-packet
interval, up to the length of the evaluation interval, Tm - T1.
Therefore, when delay variation occurs and disturbs the packet
spacing observed at Ha, the PDV results will likely compare favorably
to a PDV measurement where the source is Ha and the destination is
Hb.
6. One-to-group metrics definitions 6. One-to-group metrics definitions
6.1. A Definition for one-to-group One-way Delay This metric defines metrics to measure the performance between a
source and a group of receivers.
6.1. A Definition for One-to-group One-way Delay
This metric defines a metric to measure one-way delay between a
source and a group of receivers.
6.1.1. Metric Name 6.1.1. Metric Name
Type-P-one-to-group-One-way-Delay-Vector Type-P-One-to-group-One-way-Delay-Vector
6.1.2. Metric Parameters 6.1.2. Metric Parameters
o Src, the IP address of a host acting as the source. o Src, the IP address of a host acting as the source.
o Recv1,..., RecvN, the IP addresses of the N hosts acting as o Recv1,..., RecvN, the IP addresses of the N hosts acting as
receivers. receivers.
o T, a time. o T, a time.
o dT1,...,dTn a list of time. o dT1,...,dTn a list of time.
o P, the specification of the packet type. o P, the specification of the packet type.
o Gr, the multicast group address (optional). The parameter Gr is o Gr, the receiving group identifier. The parameter Gr is the
the multicast group address if the measured packets are multicast group address if the measured packets are transmitted
transmitted by multicast. This parameter is to identify the over IP multicast. This parameter is to differentiate the
measured traffic from other unicast and multicast traffic. It is measured traffic from other unicast and multicast traffic. It is
set to be optional in the metric to avoid losing any generality, optional in the metric to avoid losing any generality, i.e. to
i.e. to make the metric also applicable to unicast measurement make the metric also applicable to unicast measurement where there
where there is only one receivers. is only one receiver.
6.1.3. Metric Units 6.1.3. Metric Units
The value of a Type-P-one-to-group-One-way-Delay-Vector is a set of The value of a Type-P-One-to-group-One-way-Delay-Vector is a set of
singletons metrics Type-P-One-way-Delay [RFC2679]. Type-P-One-way-Delay singletons [RFC2679].
6.1.4. Definition 6.1.4. Definition
Given a Type P packet sent by the source Src at Time T, given the N 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 { hosts { Recv1,...,RecvN } which receive the packet at the time {
T+dT1,...,T+dTn }, a Type-P-one-to-group-One-way-Delay-Vector is T+dT1,...,T+dTn }, a Type-P-One-to-group-One-way-Delay-Vector is
defined as the set of the Type-P-One-way-Delay singleton between Src defined as the set of the Type-P-One-way-Delay singleton between Src
and each receiver with value of { dT1, dT2,...,dTn }. and each receiver with value of { dT1, dT2,...,dTn }.
6.2. A Definition for one-to-group One-way Packet Loss 6.2. A Definition for One-to-group One-way Packet Loss
6.2.1. Metric Name 6.2.1. Metric Name
Type-P-one-to-group-One-way-Packet-Loss-Vector Type-P-One-to-group-One-way-Packet-Loss-Vector
6.2.2. Metric Parameters 6.2.2. Metric Parameters
o Src, the IP address of a host acting as the source. o Src, the IP address of a host acting as the source.
o Recv1,..., RecvN, the IP addresses of the N hosts acting as o Recv1,..., RecvN, the IP addresses of the N hosts acting as
receivers. receivers.
o T, a time. o T, a time.
o T1,...,Tn a list of time. o T1,...,Tn a list of time.
o P, the specification of the packet type. o P, the specification of the packet type.
o Gr, the multicast group address (optional). o Gr, the receiving group identifier.
6.2.3. Metric Units 6.2.3. Metric Units
The value of a Type-P-one-to-group-One-way-Packet-Loss-Vector is a The value of a Type-P-One-to-group-One-way-Packet-Loss-Vector is a
set of singletons metrics Type-P-One-way-Packet-Loss [RFC2680]. set of Type-P-One-way-Packet-Loss singletons [RFC2680].
6.2.4. Definition 6.2.4. Definition
Given a Type P packet sent by the source Src at T and the N hosts, 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 Recv1,...,RecvN, which should receive the packet at T1,...,Tn, a
Type-P-one-to-group-One-way-Packet-Loss-Vector is defined as a set of Type-P-One-to-group-One-way-Packet-Loss-Vector is defined as a set of
the Type-P-One-way-Packet-Loss singleton between Src and each of the the Type-P-One-way-Packet-Loss singleton between Src and each of the
receivers {<T1,0|1>,<T2,0|1>,..., <Tn,0|1>}. receivers {<T1,0|1>,<T2,0|1>,..., <Tn,0|1>}.
6.3. A Definition for one-to-group One-way Ipdv 6.3. A Definition for One-to-group One-way Ipdv
6.3.1. Metric Name 6.3.1. Metric Name
Type-P-One-to-group-One-way-ipdv-Vector Type-P-One-to-group-One-way-ipdv-Vector
6.3.2. Metric Parameters 6.3.2. Metric Parameters
+ Src, the IP address of a host acting as the source. o Src, the IP address of a host acting as the source.
+ Recv1,..., RecvN, the IP addresses of the N hosts acting as o Recv1,..., RecvN, the IP addresses of the N hosts acting as
receivers. receivers.
+ T1, a time. o T1, a time.
+ T2, a time. o T2, a time.
+ ddT1,...,ddTn, a list of time. o ddT1, ...,ddTn, a list of time.
+ P, the specification of the packet type. o P, the specification of the packet type.
+ F, a selection function defining unambiguously the two o F, a selection function defining unambiguously the two packets
packets from the stream selected for the metric. from the stream selected for the metric.
+ Gr, the multicast group address (optional) o Gr, the receiving group identifier.
6.3.3. Metric Units 6.3.3. Metric Units
The value of a Type-P-One-to-group-One-way-ipdv-Vector is a set of The value of a Type-P-One-to-group-One-way-ipdv-Vector is a set of
singletons metrics Type-P-One-way-ipdv [RFC3393]. Type-P-One-way-ipdv singletons [RFC3393].
6.3.4. Definition 6.3.4. Definition
Given a Type P packet stream, Type-P-one-to-group-One-way-ipdv-Vector Given a Type P packet stream, Type-P-One-to-group-One-way-ipdv-Vector
is defined for two packets from the source Src to the N hosts is defined for two packets from the source Src to the N hosts
{Recv1,...,RecvN },which are selected by the selection function F, as {Recv1,...,RecvN },which are selected by the selection function F, as
the difference between the value of the Type-P-one-to-group-One-way- the difference between the value of the Type-P-One-to-group-One-way-
Delay-Vector from Src to { Recv1,..., RecvN } at time T1 and the Delay-Vector from Src to { Recv1,..., RecvN } at time T1 and the
value of the Type-P-one-to-group- One-way-Delay-Vector from Src to { value of the Type-P-One-to-group-One-way-Delay-Vector from Src to {
Recv1,...,RecvN } at time T2. T1 is the wire-time at which Src sent Recv1,...,RecvN } at time T2. T1 is the wire-time at which Src sent
the first bit of the first packet, and T2 is the wire-time at which the first bit of the first packet, and T2 is the wire-time at which
Src sent the first bit of the second packet. This metric is derived Src sent the first bit of the second packet. This metric is derived
from the Type-P-one-to- group-One-way-Delay-Vector metric. from the Type-P-One-to-group-One-way-Delay-Vector metric.
Therefore, for a set of real number {ddT1,...,ddTn},Type-P-one- to- Therefore, for a set of real number {ddT1,...,ddTn},Type-P-One-to-
group-One-way-ipdv-Vector from Src to { Recv1,...,RecvN } at T1, T2 group-One-way-ipdv-Vector from Src to { Recv1,...,RecvN } at T1, T2
is {ddT1,...,ddTn} means that Src sent two packets, the first at is {ddT1,...,ddTn} means that Src sent two packets, the first at
wire-time T1 (first bit), and the second at wire-time T2 (first bit) wire-time T1 (first bit), and the second at wire-time T2 (first bit)
and the packets were received by { Recv1,...,RecvN } at wire-time and the packets were received by { Recv1,...,RecvN } at wire-time
{dT1+T1,...,dTn+T1}(last bit of the first packet), and at wire-time {dT1+T1,...,dTn+T1}(last bit of the first packet), and at wire-time
{dT'1+T2,...,dT'n+T2} (last bit of the second packet), and that {dT'1+T2,...,dT'n+T2} (last bit of the second packet), and that
{dT'1-dT1,...,dT'n-dTn} ={ddT1,...,ddTn}. {dT'1-dT1,...,dT'n-dTn} ={ddT1,...,ddTn}.
7. One-to-Group Sample Statistics 7. One-to-Group Sample Statistics
The defined one-to-group metrics above can all be directly achieved The defined one-to-group metrics above can all be directly achieved
from the relevant unicast one-way metrics. They managed to collect from the relevant unicast one-way metrics. They collect all unicast
all unicast measurement results of one-way metrics together in one measurement results of one-way metrics together in one profile and
profile and sort them by receivers and packets in a multicast group. sort them by receivers and packets in a receiving group. They
They can provide sufficient information regarding the network provide sufficient information regarding the network performance in
performance in terms of each receiver and guide engineers to identify terms of each receiver and guide engineers to identify potential
potential problem happened on each branch of a multicast routing problem happened on each branch of a multicast routing tree.
tree. However, these metrics can not be directly used to
conveniently present the performance in terms of a group and neither However, these metrics cannot be directly used to conveniently
to identify the relative performance situation. present the performance in terms of a group and neither to identify
the relative performance situation.
From the performance point of view, the multiparty communication From the performance point of view, the multiparty communication
services not only require the absolute performance support but also services not only require the absolute performance support but also
the relative performance. The relative performance means the the relative performance. The relative performance means the
difference between absolute performance of all users. Directly using difference between absolute performance of all users. Directly using
the one-way metrics cannot present the relative performance the one-way metrics cannot present the relative performance
situation. However, if we use the variations of all users one-way situation. However, if we use the variations of all users one-way
parameters, we can have new metrics to measure the difference of the parameters, we can have new metrics to measure the difference of the
absolute performance and hence provide the threshold value of absolute performance and hence provide the threshold value of
relative performance that a multiparty service might demand. A very relative performance that a multiparty service might demand. A very
skipping to change at page 27, line 13 skipping to change at page 29, line 39
and report the group performance and relative performance to save the and report the group performance and relative performance to save the
report transmission bandwidth. Statistics have been defined for One- report transmission bandwidth. Statistics have been defined for One-
way metrics in corresponding RFCs. They provide the foundation of way metrics in corresponding RFCs. They provide the foundation of
definition for performance statistics. For instance, there are definition for performance statistics. For instance, there are
definitions for minimum and maximum One-way delay in [RFC2679]. definitions for minimum and maximum One-way delay in [RFC2679].
However, there is a dramatic difference between the statistics for However, there is a dramatic difference between the statistics for
one-to-one communications and for one-to-many communications. The one-to-one communications and for one-to-many communications. The
former one only has statistics over the time dimension while the former one only has statistics over the time dimension while the
later one can have statistics over both time and space dimensions. later one can have statistics over both time and space dimensions.
This space dimension is introduced by the Matrix concept as This space dimension is introduced by the Matrix concept as
illustrated in Figure 9. For a Matrix M each row is a set of One-way illustrated in Figure 4. For a Matrix M each row is a set of One-way
singletons spreading over the time dimension and each column is singletons spreading over the time dimension and each column is
another set of One-way singletons spreading over the space dimension. another set of One-way singletons spreading over the space dimension.
Receivers Receivers
Space Space
^ ^
1 | / R1dT1 R1dT2 R1dT3 ... R3dTk \ 1 | / R1dT1 R1dT2 R1dT3 ... R3dTk \
| | | | | |
2 | | R2dT1 R2dT2 R2dT3 ... R3dTk | 2 | | R2dT1 R2dT2 R2dT3 ... R3dTk |
| | | | | |
3 | | R3dT1 R3dT2 R3dT3 ... R3dTk | 3 | | R3dT1 R3dT2 R3dT3 ... R3dTk |
. | | | . | | |
. | | | . | | |
. | | | . | | |
n | \ RndT1 RndT2 RndT3 ... RndTk / n | \ RndT1 RndT2 RndT3 ... RndTk /
+--------------------------------------------> time +--------------------------------------------> time
T0 T0
Figure 9: Matrix M (n*m) Figure 4: Matrix M (n*m)
In Matrix M, each element is a One-way delay singleton. Each column In Matrix M, each element is a one-way delay singleton. Each column
is a delay vector contains the One-way delays of the same packet is a delay vector contains the One-way delays of the same packet
observed at M points of interest. It implies the geographical factor observed at M points of interest. It implies the geographical factor
of the performance within a group. Each row is a set of One-way of the performance within a group. Each row is a set of One-way
delays observed during a sampling interval at one of the points of delays observed during a sampling interval at one of the points of
interest. It presents the delay performance at a receiver over the interest. It presents the delay performance at a receiver over the
time dimension. time dimension.
Therefore, one can either calculate statistics by rows over the space Therefore, one can either calculate statistics by rows over the space
dimension or by columns over the time dimension. It's up to the dimension or by columns over the time dimension. It's up to the
operators or service provides which dimension they are interested in. operators or service provides which dimension they are interested in.
For example, a TV broadcast service provider might want to know the 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 statistical performance of each user in a long term run to make sure
their services are acceptable and stable. While for an online gaming their services are acceptable and stable. While for an online gaming
service provider, he might be more interested to know if all users service provider, he might be more interested to know if all users
are served fairly by calculating the statistics over the space are served fairly by calculating the statistics over the space
dimension. This memo does not intend to recommend which of the dimension. This memo does not intend to recommend which of the
statistics are better than the other. statistics are better than the other.
To save the report transmission bandwidth, each point of interest can To save the report transmission bandwidth, each point of interest can
send statistics in a pre-defined time interval to the reference point send statistics in a pre-defined time interval to the reference point
rather than sending every One-way singleton it observed. As long as rather than sending every one-way singleton it observed. As long as
an appropriate time interval is decided, appropriate statistics can an appropriate time interval is decided, appropriate statistics can
represent the performance in a certain accurate scale. How to decide represent the performance in a certain accurate scale. How to decide
the time interval and how to bootstrap all points of interest and the the time interval and how to bootstrap all points of interest and the
reference point depend on applications. For instance, applications reference point depend on applications. For instance, applications
with lower transmission rate can have the time interval longer and with lower transmission rate can have the time interval longer and
ones with higher transmission rate can have the time interval ones with higher transmission rate can have the time interval
shorter. However, this is out of the scope of this memo. shorter. However, this is out of the scope of this memo.
Moreover, after knowing the statistics over the time dimension, one Moreover, after knowing the statistics over the time dimension, one
might want to know how this statistics distributed over the space might want to know how this statistics distributed over the space
skipping to change at page 30, line 7 skipping to change at page 32, line 38
User1 calculates the Type-P-Finite-One-way-Delay-Mean R1DM as shown User1 calculates the Type-P-Finite-One-way-Delay-Mean R1DM as shown
in Figure. 8 without any packet loss and User2 calculates the R2DM in Figure. 8 without any packet loss and User2 calculates the R2DM
with N-2 packet loss. The R1DM and R2DM should not be treated with with N-2 packet loss. The R1DM and R2DM should not be treated with
equal weight because R2DM was calculated only based on 2 delay values equal weight because R2DM was calculated only based on 2 delay values
in the whole sample interval. One possible solution is to use a in the whole sample interval. One possible solution is to use a
weight factor to mark every statistic value sent by users and use weight factor to mark every statistic value sent by users and use
this factor for further statistic calculation. this factor for further statistic calculation.
7.2. General Metric Parameters 7.2. General Metric Parameters
o Src, the IP address of a host o Src, the IP address of a host;
o G, the Group IP address o G, the receiving group identifier;
o N, the number of Receivers (Recv1, Recv2, ... RecvN) o N, the number of Receivers (Recv1, Recv2, ... RecvN);
o T, a time (start of test interval) o T, a time (start of test interval);
o Tf, a time (end of test interval) o Tf, a time (end of test interval);
o K, the number of packets sent from the source during the test o K, the number of packets sent from the source during the test
interval interval;
o J[n], the number of packets received at a particular Receiver, n, o J[n], the number of packets received at a particular Receiver, n,
where 1<=n<=N where 1<=n<=N;
o lambda, a rate in reciprocal seconds (for Poisson Streams) o lambda, a rate in reciprocal seconds (for Poisson Streams);
o incT, the nominal duration of inter-packet interval, first bit to o incT, the nominal duration of inter-packet interval, first bit to
first bit (for Periodic Streams) first bit (for Periodic Streams);
o T0, a time that MUST be selected at random from the interval [T, o T0, a time that MUST be selected at random from the interval [T,
T+I] to start generating packets and taking measurements (for T+I] to start generating packets and taking measurements (for
Periodic Streams) Periodic Streams);
o TstampSrc, the wire time of the packet as measured at MP(Src) (the o TstampSrc, the wire time of the packet as measured at MP(Src) (the
Source Measurement Point) Source Measurement Point);
o TstampRecv, the wire time of the packet as measured at MP(Recv), o TstampRecv, the wire time of the packet as measured at MP(Recv),
assigned to packets that arrive within a "reasonable" time assigned to packets that arrive within a "reasonable" time;
o Tmax, a maximum waiting time for packets at the destination, set o Tmax, a maximum waiting time for packets at the destination, set
sufficiently long to disambiguate packets with long delays from sufficiently long to disambiguate packets with long delays from
packets that are discarded (lost), thus the distribution of delay packets that are discarded (lost), thus the distribution of delay
is not truncated is not truncated;
o dT, shorthand notation for a one-way delay singleton value o dT, shorthand notation for a one-way delay singleton value;
o L, shorthand notation for a one-way loss singleton value, either o L, shorthand notation for a one-way loss singleton value, either
zero or one, where L=1 indicates loss and L=0 indicates arrival at zero or one, where L=1 indicates loss and L=0 indicates arrival at
the destination within TstampSrc + Tmax, may be indexed over n the destination within TstampSrc + Tmax, may be indexed over n
Receivers Receivers;
o DV, shorthand notation for a one-way delay variation singleton o DV, shorthand notation for a one-way delay variation singleton
value value;
7.3. One-to-Group one-way Delay Statistics 7.3. One-to-Group one-way Delay Statistics
This section defines the overall one-way delay statistics for an This section defines the overall one-way delay statistics for an
entire Group or receivers. For example, we can define the group mean entire Group or receivers. For example, we can define the group mean
delay, as illustrated below. This is a metric designed to summarize delay, as illustrated below. This is a metric designed to summarize
the whole matrix. the whole matrix.
Recv /----------- Sample -------------\ Stats Group Stat Recv /----------- Sample -------------\ Stats Group Stat
1 R1dT1 R1dT2 R1dT3 ... R1dTk R1DM \ 1 R1dT1 R1dT2 R1dT3 ... R1dTk R1DM \
| |
2 R2dT1 R2dT2 R2dT3 ... R2dTk R2DM | 2 R2dT1 R2dT2 R2dT3 ... R2dTk R2DM |
| |
3 R3dT1 R3dT2 R3dT3 ... R3dTk R2DM > GMD 3 R3dT1 R3dT2 R3dT3 ... R3dTk R2DM > GMD
. | . |
. | . |
. | . |
skipping to change at page 31, line 23 skipping to change at page 34, line 17
1 R1dT1 R1dT2 R1dT3 ... R1dTk R1DM \ 1 R1dT1 R1dT2 R1dT3 ... R1dTk R1DM \
| |
2 R2dT1 R2dT2 R2dT3 ... R2dTk R2DM | 2 R2dT1 R2dT2 R2dT3 ... R2dTk R2DM |
| |
3 R3dT1 R3dT2 R3dT3 ... R3dTk R2DM > GMD 3 R3dT1 R3dT2 R3dT3 ... R3dTk R2DM > GMD
. | . |
. | . |
. | . |
n RndT1 RndT2 RndT3 ... RndTk RnDM / n RndT1 RndT2 RndT3 ... RndTk RnDM /
Figure 10: One-to-GroupGroup Mean Delay Figure 5: One-to-Group Mean Delay
where: where:
R1dT1 is the Type-P-Finite-One-way-Delay singleton evaluated at R1dT1 is the Type-P-Finite-One-way-Delay singleton evaluated at
Receiver 1 for packet 1. Receiver 1 for packet 1.
R1DM is the Type-P-Finite-One-way-Delay-Mean evaluated at Receiver 1 R1DM is the Type-P-Finite-One-way-Delay-Mean evaluated at Receiver 1
for the sample of packets (1,...K). for the sample of packets (1,...K).
GMD is the mean of the sample means over all Receivers (1, ...N). GMD is the mean of the sample means over all Receivers (1, ...N).
skipping to change at page 32, line 18 skipping to change at page 35, line 14
Type-P-Finite-One-way-Delay-Mean-Receiver-n = RnDM = Type-P-Finite-One-way-Delay-Mean-Receiver-n = RnDM =
J[n] J[n]
--- ---
1 \ 1 \
--- * > Type-P-Finite-One-way-Delay-Receiver-n-[i] --- * > Type-P-Finite-One-way-Delay-Receiver-n-[i]
J[n] / J[n] /
--- ---
i = 1 i = 1
Figure 11: Type-P-Finite-One-way-Delay-Mean-Receiver-n Figure 6: Type-P-Finite-One-way-Delay-Mean-Receiver-n
where all packets i= 1 through J[n] have finite singleton delays. where all packets i= 1 through J[n] have finite singleton delays.
7.3.3. One-to-Group Mean Delay Statistic 7.3.3. One-to-Group Mean Delay Statistic
This section defines the Mean One-way Delay calculated over the This section defines the Mean One-way Delay calculated over the
entire Group (or Matrix). entire Group (or Matrix).
Type-P-One-to-Group-Mean-Delay = GMD = Type-P-One-to-Group-Mean-Delay = GMD =
N N
--- ---
1 \ 1 \
- * > RnDM - * > RnDM
N / N /
--- ---
n = 1 n = 1
Figure 12: Type-P-One-to-Group-Mean-Delay Figure 7: Type-P-One-to-Group-Mean-Delay
Note that the Group Mean Delay can also be calculated by summing the Note that the Group Mean Delay can also be calculated by summing the
Finite one-way Delay singletons in the Matrix, and dividing by the Finite one-way Delay singletons in the Matrix, and dividing by the
number of Finite One-way Delay singletons. number of Finite One-way Delay singletons.
7.3.4. One-to-Group Range of Mean Delays 7.3.4. One-to-Group Range of Mean Delays
This section defines a metric for the range of mean delays over all N This section defines a metric for the range of mean delays over all N
receivers in the Group, (R1DM, R2DM,...RnDM). receivers in the Group, (R1DM, R2DM,...RnDM).
skipping to change at page 33, line 26 skipping to change at page 36, line 24
1 R1L1 R1L2 R1L3 ... R1Lk R1LR \ 1 R1L1 R1L2 R1L3 ... R1Lk R1LR \
| |
2 R2L1 R2L2 R2L3 ... R2Lk R2LR | 2 R2L1 R2L2 R2L3 ... R2Lk R2LR |
| |
3 R3L1 R3L2 R3L3 ... R3Lk R3LR > GLR 3 R3L1 R3L2 R3L3 ... R3Lk R3LR > GLR
. | . |
. | . |
. | . |
n RnL1 RnL2 RnL3 ... RnLk RnLR / n RnL1 RnL2 RnL3 ... RnLk RnLR /
Figure 13: One-to-Group Loss Ratio Figure 8: One-to-Group Loss Ratio
where: where:
R1L1 is the Type-P-One-way-Loss singleton (L) evaluated at Receiver 1 R1L1 is the Type-P-One-way-Loss singleton (L) evaluated at Receiver 1
for packet 1. for packet 1.
R1LR is the Type-P-One-way-Loss-Ratio evaluated at Receiver 1 for the R1LR is the Type-P-One-way-Loss-Ratio evaluated at Receiver 1 for the
sample of packets (1,...K). sample of packets (1,...K).
GLR is the loss ratio over all Receivers (1, ..., N). GLR is the loss ratio over all Receivers (1, ..., N).
skipping to change at page 34, line 12 skipping to change at page 37, line 12
Type-P-One-to-Group-Loss-Ratio = Type-P-One-to-Group-Loss-Ratio =
K,N K,N
--- ---
1 \ 1 \
= --- * > L(k,n) = --- * > L(k,n)
K*N / K*N /
--- ---
k,n = 1 k,n = 1
Figure 14 Figure 9
ALL Loss ratios are expressed in units of packets lost to total ALL Loss ratios are expressed in units of packets lost to total
packets sent. packets sent.
7.4.2. One-to-Group Loss Ratio Range 7.4.2. One-to-Group Loss Ratio Range
Given a Matrix of loss singletons as illustrated above, determine the Given a Matrix of loss singletons as illustrated above, determine the
Type-P-One-way-Packet-Loss-Average for the sample at each receiver, Type-P-One-way-Packet-Loss-Average for the sample at each receiver,
according to the definitions and method of [RFC2680]. The Type-P- according to the definitions and method of [RFC2680]. The Type-P-
One-way-Packet-Loss-Average, RnLR for receiver n, and the Type-P-One- One-way-Packet-Loss-Average, RnLR for receiver n, and the Type-P-One-
skipping to change at page 34, line 36 skipping to change at page 37, line 36
Type-P-One-way-Loss-Ratio-Receiver-n = RnLR = Type-P-One-way-Loss-Ratio-Receiver-n = RnLR =
K K
--- ---
1 \ 1 \
- * > RnLk - * > RnLk
K / K /
--- ---
k = 1 k = 1
Figure 15: Type-P-One-way-Loss-Ratio-Receiver-n Figure 10: Type-P-One-way-Loss-Ratio-Receiver-n
The One-to-Group Loss Ratio Range is defined as The One-to-Group Loss Ratio Range is defined as
Type-P-One-to-Group-Loss-Ratio-Range = max(RnLR) - min(RnLR) Type-P-One-to-Group-Loss-Ratio-Range = max(RnLR) - min(RnLR)
It is most effective to indicate the range by giving both the max and It is most effective to indicate the range by giving both the max and
minimum loss ratios for the Group, rather than only reporting the minimum loss ratios for the Group, rather than only reporting the
difference between them. difference between them.
7.4.3. Comparative Loss Ratio 7.4.3. Comparative Loss Ratio
skipping to change at page 35, line 24 skipping to change at page 38, line 24
k=1 k=1
= ----------------------------- = -----------------------------
/ K \ / K \
| --- | | --- |
| \ | | \ |
K - Min | > Ln(k) | K - Min | > Ln(k) |
| / | | / |
| --- | | --- |
\ k=1 / N \ k=1 / N
Figure 16: Type-P-Comp-Loss-Ratio-Receiver-n Figure 11: Type-P-Comp-Loss-Ratio-Receiver-n
7.5. One-to-Group one-way Delay Variation Statistics 7.5. One-to-Group one-way Delay Variation Statistics
There are two delay variation (DV) statistics that summarize the There are two delay variation (DV) statistics that summarize the
performance over the Group: the maximum DV over all receivers and the performance over the Group: the maximum DV over all receivers and the
minimum DV over all receivers (where DV is a point-to-point metric). minimum DV over all receivers (where DV is a point-to-point metric).
For each receiver, the DV is usually expressed as the 1-10^(-3) For each receiver, the DV is usually expressed as the 1-10^(-3)
quantile of one-way delay minus the minimum one-way delay. quantile of one-way delay minus the minimum one-way delay.
8. Measurement Methods: Scaleability and Reporting 8. Measurement Methods: Scalability and Reporting
Virtually all the guidance on measurement processes supplied by the Virtually all the guidance on measurement processes supplied by the
earlier IPPM RFCs (such as [RFC2679] and [RFC2680]) for one-to-one earlier IPPM RFCs (such as [RFC2679] and [RFC2680]) for one-to-one
scenarios is applicable here in the spatial and multiparty scenarios is applicable here in the spatial and multiparty
measurement scenario. The main difference is that the spatial and measurement scenario. The main difference is that the spatial and
multiparty configurations require multiple measurement points where a multiparty configurations require multiple measurement points where a
stream of singletons will be collected. The amount of information stream of singletons will be collected. The amount of information
requiring storage grows with both the number of metrics and the requiring storage grows with both the number of metrics and the
number of measurement points, so the scale of the measurement number of measurement points, so the scale of the measurement
architecture multiplies the number of singleton results that must be architecture multiplies the number of singleton results that must be
skipping to change at page 37, line 44 skipping to change at page 40, line 44
. | . |
. | . |
n RnS1 RnS2 RnS3 ... RnSk / n RnS1 RnS2 RnS3 ... RnSk /
S1M S2M S3M ... SnM Stats over space S1M S2M S3M ... SnM Stats over space
\------------- ------------/ \------------- ------------/
\/ \/
Stat over space and time Stat over space and time
Figure 17: Impact of space aggregation on multimetrics Stat Figure 12: Impact of space aggregation on multimetrics Stat
2 methods are available to compute statistics on the resulting 2 methods are available to compute statistics on the resulting
matrix: matrix:
o metric is computed over time and then over space; o metric is computed over time and then over space;
o metric is computed over space and then over time. o metric is computed over space and then over time.
They differ only by the order of the time and of the space They differ only by the order of the time and of the space
aggregation. View as a matrix this order is neutral as does not aggregation. View as a matrix this order is neutral as does not
impact the result, but the impact on a measurement deployment is impact the result, but the impact on a measurement deployment is
skipping to change at page 38, line 48 skipping to change at page 41, line 48
Note: In some specific cases one may need sample of singletons over Note: In some specific cases one may need sample of singletons over
space. To address this need it is suggested firstly to limit the space. To address this need it is suggested firstly to limit the
number of test and the number of test packets per seconds. Then number of test and the number of test packets per seconds. Then
reducing the size of the sample over time to one packet give sample reducing the size of the sample over time to one packet give sample
of singleton over space.. of singleton over space..
8.3.1. Impact on group stats 8.3.1. Impact on group stats
2 methods are available to compute group statistics: 2 methods are available to compute group statistics:
o method1: Figure 10 andFigure 13 illustrate the method chosen: the o method1: Figure 5 andFigure 8 illustrate the method chosen: the
one-to-one statistic is computed per interval of time before the one-to-one statistic is computed per interval of time before the
computation of the mean over the group of receivers; computation of the mean over the group of receivers;
o method2: Figure 17 presents the second one, metric is computed o method2: Figure 12 presents the second one, metric is computed
over space and then over time. over space and then over time.
8.3.2. Impact on spatial stats 8.3.2. Impact on spatial stats
2 methods are available to compute spatial statistics: 2 methods are available to compute spatial statistics:
o method 1: spatial segment metrics and statistics are preferably o method 1: spatial segment metrics and statistics are preferably
computed over time by each points of interest; computed over time by each points of interest;
o method 2: Vectors metrics are intrinsically instantaneous space o method 2: Vectors metrics are intrinsically instantaneous space
skipping to change at page 41, line 30 skipping to change at page 44, line 30
As explained in section 8, the measurement method will have impact on As explained in section 8, the measurement method will have impact on
the analysis of the measurement result. Therefore, it should be the analysis of the measurement result. Therefore, it should be
reported. reported.
9.3. Metric identification 9.3. Metric identification
IANA assigns each metric defined by the IPPM WG with a unique IANA assigns each metric defined by the IPPM WG with a unique
identifier as per [RFC4148] in the IANA-IPPM-METRICS-REGISTRY-MIB. identifier as per [RFC4148] in the IANA-IPPM-METRICS-REGISTRY-MIB.
To avoid misunderstanding and to address specific reporting
constraints, section [passive_metrics] of this memo gives distinct
names to passive metrics and Section 13 requests a distinct metric
identifier for each metrics the memo defines.
As it is crucial for composition of metrics to know the methodology
used (e.g. generation method, detection method...), the report of a
metric result used in composition of metrics MUST always include its
metric identifier.
9.4. Reporting data model 9.4. Reporting data model
This section presents the elements of the datamodel and the usage of This section presents the elements of the datamodel and the usage of
the information reported for real network performance analysis. It the information reported for real network performance analysis. It
is out of the scope of this section to define how the information is is out of the scope of this section to define how the information is
reported. reported.
The data model is build with pieces of information introduced and The data model is build with pieces of information introduced and
explained in one-way delay definitions [RFC2679], in packet loss explained in one-way delay definitions [RFC2679], in packet loss
definitions [RFC2680] and in IPDV definitions[RFC3393][RFC3432]. It definitions [RFC2680] and in IPDV definitions[RFC3393][RFC3432]. It
skipping to change at page 46, line 14 skipping to change at page 49, line 5
13. IANA Considerations 13. IANA Considerations
Metrics defined in this memo Metrics defined in this memo are Metrics defined in this memo Metrics defined in this memo are
designed to be registered in the IANA IPPM METRICS REGISTRY as designed to be registered in the IANA IPPM METRICS REGISTRY as
described in initial version of the registry [RFC4148] : described in initial version of the registry [RFC4148] :
IANA is asked to register the following metrics in the IANA-IPPM- IANA is asked to register the following metrics in the IANA-IPPM-
METRICS-REGISTRY-MIB : METRICS-REGISTRY-MIB :
Spatial-One-way-Delay-Vector OBJECT-IDENTITY ietfSpatialOneWayDelayVector OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-Spatial-One-way-Delay-Vector" "Type-P-Spatial-One-way-Delay-Vector"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 4.1." "Reference "RFCyyyy, section 4.1."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
Spatial-Packet-Loss-Vector OBJECT-IDENTITY ietfSpatialPacketLossVector OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-Spatial-Packet-Loss-Vector" "Type-P-Spatial-Packet-Loss-Vector"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 4.2." "Reference "RFCyyyy, section 4.2."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
Spatial-One-way-ipdv-Vector OBJECT-IDENTITY ietfSpatialOneWayIpdvVector OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-Spatial-One-way-ipdv-Vector" "Type-P-Spatial-One-way-ipdv-Vector"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 4.3." "Reference "RFCyyyy, section 4.3."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
Spatial-Segment-One-way-Delay-Stream OBJECT-IDENTITY ietfSpatialSegmentOnewayDelayStream OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-Spatial-Segment-One-way-Delay-Stream" "Type-P-Spatial-Segment-One-way-Delay-Stream"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 5.1." "Reference "RFCyyyy, section 5.1."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
Spatial-Segment-Packet-Loss-Stream OBJECT-IDENTITY ietfSpatialSegmentPacketLossStream OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-Spatial-Segment-Packet-Loss-Stream" "Type-P-Spatial-Segment-Packet-Loss-Stream"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 5.2." "Reference "RFCyyyy, section 5.2."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
Spatial-Segment-One-way-ipdv-Stream OBJECT-IDENTITY
ietfSpatialSegmentOneWayIpdvPrevStream OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-Spatial-Segment-ipdv-Stream" "Type-P-Spatial-Segment-ipdv-prev-Stream"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 5.3." "Reference "RFCyyyy, section 5.3."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
ietfSpatialSegmentOneWayIpdvMinStream OBJECT-IDENTITY
STATUS current
DESCRIPTION
"Type-P-Spatial-Segment-ipdv-minStream"
REFERENCE
"Reference "RFCyyyy, section 5.4."
-- RFC Ed.: replace yyyy with actual RFC number & remove this
note
:= { ianaIppmMetrics nn } -- IANA assigns nn
-- One-to-group metrics -- One-to-group metrics
one-to-group-One-way-Delay-Vector OBJECT-IDENTITY ietfOneToGroupOneWayDelayVector OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-one-to-group-One-way-Delay-Vector" "Type-P-one-to-group-One-way-Delay-Vector"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 5.1." "Reference "RFCyyyy, section 6.1."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
one-to-group-One-way-Packet-Loss-Vector OBJECT-IDENTITY ietfOneToGroupOneWayPktLossVector OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-one-to-group-One-way-Packet-Loss-Vector" "Type-P-one-to-group-One-way-Packet-Loss-Vector"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 5.2." "Reference "RFCyyyy, section 6.2."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
one-to-group-One-way-ipdv-Vector OBJECT-IDENTITY ietfOneToGroupOneWayIpdvVector OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-one-to-group-One-way-ipdv-Vector" "Type-P-one-to-group-One-way-ipdv-Vector"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 5.3." "Reference "RFCyyyy, section 6.3."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
One-to-Group-Mean-Delay OBJECT-IDENTITY -- One to group statistics
--
ietfOneToGroupMeanDelay OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-One-to-Group-Mean-Delay" "Type-P-One-to-Group-Mean-Delay"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 6.3.3." "Reference "RFCyyyy, section 6.3.3."
skipping to change at page 49, line 37 skipping to change at page 53, line 4
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-One-to-Group-Mean-Delay" "Type-P-One-to-Group-Mean-Delay"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 6.3.3." "Reference "RFCyyyy, section 6.3.3."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
One-to-Group-Range-Mean-Delay OBJECT-IDENTITY ietfOneToGroupRangeMeanDelay OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-One-to-Group-Range-Mean-Delay" "Type-P-One-to-Group-Range-Mean-Delay"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 6.3.4." "Reference "RFCyyyy, section 6.3.4."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
One-to-Group-Max-Mean-Delay OBJECT-IDENTITY ietfOneToGroupMaxMeanDelay OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-One-to-Group-Max-Mean-Delay" "Type-P-One-to-Group-Max-Mean-Delay"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 6.3.5." "Reference "RFCyyyy, section 6.3.5."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
One-to-Group-Loss-Ratio OBJECT-IDENTITY ietfOneToGroupLossRatio OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-One-to-Group-Loss-Ratio" "Type-P-One-to-Group-Loss-Ratio"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 6.4.1." "Reference "RFCyyyy, section 6.4.1."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
-- --
skipping to change at page 50, line 49 skipping to change at page 54, line 15
"Reference "RFCyyyy, section 6.4.1." "Reference "RFCyyyy, section 6.4.1."
-- RFC Ed.: replace yyyy with actual RFC number & remove this -- RFC Ed.: replace yyyy with actual RFC number & remove this
note note
:= { ianaIppmMetrics nn } -- IANA assigns nn := { ianaIppmMetrics nn } -- IANA assigns nn
-- --
One-to-Group-Loss-Ratio-Range OBJECT-IDENTITY ietfOneToGroupLossRatioRange OBJECT-IDENTITY
STATUS current STATUS current
DESCRIPTION DESCRIPTION
"Type-P-One-to-Group-Loss-Ratio-Range" "Type-P-One-to-Group-Loss-Ratio-Range"
REFERENCE REFERENCE
"Reference "RFCyyyy, section 6.4.2." "Reference "RFCyyyy, section 6.4.2."
skipping to change at page 54, line 7 skipping to change at page 57, line 7
Al Morton Al Morton
200 Laurel Ave. South 200 Laurel Ave. South
Middletown, NJ 07748 Middletown, NJ 07748
USA USA
Phone: +1 732 420 1571 Phone: +1 732 420 1571
Email: acmorton@att.com Email: acmorton@att.com
Full Copyright Statement Full Copyright Statement
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
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