draft-ietf-lmap-framework-03.txt   draft-ietf-lmap-framework-04.txt 
Network Working Group P. Eardley Network Working Group P. Eardley
Internet-Draft BT Internet-Draft BT
Intended status: Informational A. Morton Intended status: Informational A. Morton
Expires: July 25, 2014 AT&T Labs Expires: October 2, 2014 AT&T Labs
M. Bagnulo M. Bagnulo
UC3M UC3M
T. Burbridge T. Burbridge
BT BT
P. Aitken P. Aitken
A. Akhter A. Akhter
Cisco Systems Cisco Systems
January 21, 2014 March 31, 2014
A framework for large-scale measurement platforms (LMAP) A framework for large-scale measurement platforms (LMAP)
draft-ietf-lmap-framework-03 draft-ietf-lmap-framework-04
Abstract Abstract
Measuring broadband service on a large scale requires a description Measuring broadband service on a large scale requires a description
of the logical architecture and standardisation of the key protocols of the logical architecture and standardisation of the key protocols
that coordinate interactions between the components. The document that coordinate interactions between the components. The document
presents an overall framework for large-scale measurements. It also presents an overall framework for large-scale measurements. It also
defines terminology for LMAP (large-scale measurement platforms). defines terminology for LMAP (large-scale measurement platforms).
Status of This Memo Status of This Memo
skipping to change at page 1, line 42 skipping to change at page 1, line 42
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on July 25, 2014. This Internet-Draft will expire on October 2, 2014.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
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publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 27 skipping to change at page 2, line 27
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Outline of an LMAP-based measurement system . . . . . . . . . 5 2. Outline of an LMAP-based measurement system . . . . . . . . . 5
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 8 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 8
4. Constraints . . . . . . . . . . . . . . . . . . . . . . . . . 11 4. Constraints . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1. Measurement system is under the direction of a single 4.1. Measurement system is under the direction of a single
organisation . . . . . . . . . . . . . . . . . . . . . . 11 organisation . . . . . . . . . . . . . . . . . . . . . . 11
4.2. Each MA may only have a single Controller at any point in 4.2. Each MA may only have a single Controller at any point in
time . . . . . . . . . . . . . . . . . . . . . . . . . . 12 time . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5. LMAP Protocol Model . . . . . . . . . . . . . . . . . . . . . 12 5. LMAP Protocol Model . . . . . . . . . . . . . . . . . . . . . 12
5.1. Bootstrapping process . . . . . . . . . . . . . . . . . . 13 5.1. Bootstrapping process . . . . . . . . . . . . . . . . . . 13
5.2. Control Protocol . . . . . . . . . . . . . . . . . . . . 15 5.2. Control Protocol . . . . . . . . . . . . . . . . . . . . 14
5.2.1. Measurement Suppression . . . . . . . . . . . . . . . 18 5.2.1. Instruction . . . . . . . . . . . . . . . . . . . . . 14
5.3. Starting and stopping Measurement Tasks . . . . . . . . . 19 5.2.2. Capabilities and Failure information . . . . . . . . 17
5.4. Report Protocol . . . . . . . . . . . . . . . . . . . . . 20 5.3. Operation of Measurement Tasks . . . . . . . . . . . . . 19
5.3.1. Starting and Stopping Measurement Tasks . . . . . . . 19
5.3.2. Overlapping Measurement Tasks . . . . . . . . . . . . 20
5.4. Report Protocol . . . . . . . . . . . . . . . . . . . . . 21
5.4.1. Reporting of Subsriber's service parameters . . . . . 22
5.5. Operation of LMAP over the underlying transport protocol 22 5.5. Operation of LMAP over the underlying transport protocol 22
5.6. Items beyond the scope of the LMAP Protocol Model . . . . 23 5.6. Items beyond the scope of the LMAP Protocol Model . . . . 23
5.6.1. Enduser-controlled measurement system . . . . . . . . 24 5.6.1. End-user-controlled measurement system . . . . . . . 24
6. Deployment considerations . . . . . . . . . . . . . . . . . . 24 6. Deployment considerations . . . . . . . . . . . . . . . . . . 25
6.1. Controller . . . . . . . . . . . . . . . . . . . . . . . 24 6.1. Controller and the measurement system . . . . . . . . . . 25
6.2. Measurement Agent . . . . . . . . . . . . . . . . . . . . 25 6.2. Measurement Agent . . . . . . . . . . . . . . . . . . . . 26
6.2.1. Measurement Agent embedded in site gateway . . . . . 26 6.2.1. Measurement Agent on a networked device . . . . . . . 26
6.2.2. Measurement Agent embedded behind site NAT /Firewall 26 6.2.2. Measurement Agent embedded in site gateway . . . . . 26
6.2.3. Measurement Agent in a multi-homed site . . . . . . . 27 6.2.3. Measurement Agent embedded behind site NAT /Firewall 27
6.3. Measurement Peer . . . . . . . . . . . . . . . . . . . . 27 6.2.4. Multi-homed Measurement Agent . . . . . . . . . . . . 27
7. Security considerations . . . . . . . . . . . . . . . . . . . 27 6.3. Measurement Peer . . . . . . . . . . . . . . . . . . . . 28
8. Privacy Considerations for LMAP . . . . . . . . . . . . . . . 28 7. Security considerations . . . . . . . . . . . . . . . . . . . 28
8.1. Categories of Entities with Information of Interest . . . 29 8. Privacy Considerations for LMAP . . . . . . . . . . . . . . . 30
8.2. Examples of Sensitive Information . . . . . . . . . . . . 29 8.1. Categories of Entities with Information of Interest . . . 30
8.2. Examples of Sensitive Information . . . . . . . . . . . . 31
8.3. Key Distinction Between Active and Passive Measurement 8.3. Key Distinction Between Active and Passive Measurement
Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . 32
8.4. Privacy analysis of the Communications Models . . . . . . 31 8.4. Privacy analysis of the Communications Models . . . . . . 33
8.4.1. MA Bootstrapping . . . . . . . . . . . . . . . . . . 31 8.4.1. MA Bootstrapping . . . . . . . . . . . . . . . . . . 33
8.4.2. Controller <-> Measurement Agent . . . . . . . . . . 32 8.4.2. Controller <-> Measurement Agent . . . . . . . . . . 34
8.4.3. Collector <-> Measurement Agent . . . . . . . . . . . 33 8.4.3. Collector <-> Measurement Agent . . . . . . . . . . . 34
8.4.4. Measurement Peer <-> Measurement Agent . . . . . . . 33 8.4.4. Measurement Peer <-> Measurement Agent . . . . . . . 35
8.4.5. Passive Measurement Agent . . . . . . . . . . . . . . 34 8.4.5. Passive Measurement Agent . . . . . . . . . . . . . . 36
8.4.6. Storage and Reporting of Measurement Results . . . . 35 8.4.6. Storage and Reporting of Measurement Results . . . . 37
8.5. Threats . . . . . . . . . . . . . . . . . . . . . . . . . 35 8.5. Threats . . . . . . . . . . . . . . . . . . . . . . . . . 37
8.5.1. Surveillance . . . . . . . . . . . . . . . . . . . . 36 8.5.1. Surveillance . . . . . . . . . . . . . . . . . . . . 38
8.5.2. Stored Data Compromise . . . . . . . . . . . . . . . 36 8.5.2. Stored Data Compromise . . . . . . . . . . . . . . . 38
8.5.3. Correlation and Identification . . . . . . . . . . . 36 8.5.3. Correlation and Identification . . . . . . . . . . . 39
8.5.4. Secondary Use and Disclosure . . . . . . . . . . . . 37 8.5.4. Secondary Use and Disclosure . . . . . . . . . . . . 39
8.6. Mitigations . . . . . . . . . . . . . . . . . . . . . . . 37 8.6. Mitigations . . . . . . . . . . . . . . . . . . . . . . . 39
8.6.1. Data Minimisation . . . . . . . . . . . . . . . . . . 37 8.6.1. Data Minimisation . . . . . . . . . . . . . . . . . . 39
8.6.2. Anonymity . . . . . . . . . . . . . . . . . . . . . . 38 8.6.2. Anonymity . . . . . . . . . . . . . . . . . . . . . . 40
8.6.3. Pseudonymity . . . . . . . . . . . . . . . . . . . . 39 8.6.3. Pseudonymity . . . . . . . . . . . . . . . . . . . . 41
8.6.4. Other Mitigations . . . . . . . . . . . . . . . . . . 39 8.6.4. Other Mitigations . . . . . . . . . . . . . . . . . . 41
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 40 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 42
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 40 10. Appendix: Deployment examples . . . . . . . . . . . . . . . . 42
11. History . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 46
11.1. From -00 to -01 . . . . . . . . . . . . . . . . . . . . 41 12. History . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
11.2. From -01 to -02 . . . . . . . . . . . . . . . . . . . . 41 12.1. From -00 to -01 . . . . . . . . . . . . . . . . . . . . 47
11.3. From -02 to -03 . . . . . . . . . . . . . . . . . . . . 42 12.2. From -01 to -02 . . . . . . . . . . . . . . . . . . . . 47
12. Informative References . . . . . . . . . . . . . . . . . . . 42 12.3. From -02 to -03 . . . . . . . . . . . . . . . . . . . . 48
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 44 12.4. From -03 to -04 . . . . . . . . . . . . . . . . . . . . 49
13. Informative References . . . . . . . . . . . . . . . . . . . 49
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 51
1. Introduction 1. Introduction
There is a desire to be able to coordinate the execution of broadband There is a desire to be able to coordinate the execution of broadband
measurements and the collection of measurement results across a large measurements and the collection of measurement results across a large
scale set of diverse devices. These devices could be software based scale set of diverse devices. These devices could be software based
agents on PCs, embedded agents in consumer devices (e.g. blu-ray agents on PCs, embedded agents in consumer devices (e.g. blu-ray
players), service provider controlled devices such as set-top players players), service provider controlled devices such as set-top players
and home gateways, or simply dedicated probes. It is expected that and home gateways, or simply dedicated probes. It is expected that
such a system could easily comprise 100k devices. Such a scale such a system could easily comprise 100,000 devices. Such a scale
presents unique problems in coordination, execution and measurement presents unique problems in coordination, execution and measurement
result collection. Several use cases have been proposed for large- result collection. Several use cases have been proposed for large-
scale measurements including: scale measurements including:
o Operators: to help plan their network and identify faults o Operators: to help plan their network and identify faults
o Regulators: to benchmark several network operators and support o Regulators: to benchmark several network operators and support
public policy development public policy development
Further details of the use cases can be found at Further details of the use cases can be found in
[I-D.ietf-lmap-use-cases]. The LMAP framework should be useful for [I-D.ietf-lmap-use-cases]. The LMAP framework should be useful for
these, as well as other use cases that the LMAP WG doesn't these, as well as other use cases, such as to help end users run
concentrate on, such as to help end users run diagnostic checks like diagnostic checks like a network speed test.
a network speed test.
The LMAP framework has four basic elements: Measurement Agents, The LMAP framework has three basic elements: Measurement Agents,
Measurement Peers, Controllers and Collectors. Controllers and Collectors.
Measurement Agents (MAs) perform Measurement Tasks, perhaps in Measurement Agents (MAs) perform the actual measurements, which are
conjunction with Measurement Peers. They are pieces of code that can called Measurement Tasks in the LMAP terminology.
be executed in specialized hardware (hardware probe) or on a general-
purpose device (like a PC or mobile phone). A device with a
Measurement Agent may have multiple interfaces (WiFi, Ethernet, DSL,
fibre, etc.) and the Measurement Tasks may specify any one of these.
Measurement Tasks may be Active (the MA or Measurement Peer generates
Active Measurement Traffic), Passive (the MA observes user traffic),
or some hybrid form of the two. For Active Measurement Tasks, the MA
(or Measurement Peer) generates Active Measurement Traffic and
measures some metric associated with its transfer over the path to
(or from) a Measurement Peer. For example, one Active Measurement
Task could be to measure the UDP latency between the MA and a given
Measurement Peer. MAs may also conduct Passive Measurement Tasks
through the observation of traffic. The Measurement Tasks themselves
may be on IPv4, IPv6, and on various services (DNS, HTTP, XMPP, FTP,
VoIP, etc.).
The Controller manages one or more MAs by instructing it which The Controller manages one or more MAs by instructing it which
Measurement Tasks it should perform and when. For example it may Measurement Tasks it should perform and when. For example it may
instruct a MA at a home gateway: "Measure the 'UDP latency' with the instruct a MA at a home gateway: "Measure the 'UDP latency' with
Measurement Peer mp.example.org; repeat every hour at xx.05". The www.example.org; repeat every hour at xx.05". The Controller also
Controller also manages a MA by instructing it how to report the manages a MA by instructing it how to report the Measurement Results,
Measurement Results, for example: "Report results once a day in a for example: "Report results once a day in a batch at 4am". We refer
batch at 4am". We refer to these as the Measurement Schedule and to these as the Measurement Schedule and Report Schedule.
Report Schedule.
The Collector accepts Reports from the MAs with the Results from The Collector accepts Reports from the MAs with the Results from
their Measurement Tasks. Therefore the MA is a device that gets their Measurement Tasks. Therefore the MA is a device that gets
Instructions from the Controller, initiates the Measurement Tasks, Instructions from the Controller, initiates the Measurement Tasks,
and reports to the Collector. and reports to the Collector.
There are additional elements that are part of a measurement system, There are additional elements that are part of a measurement system,
but that are out of the scope for LMAP. We provide a detailed but these are out of the scope for LMAP. We provide a detailed
discussion of all the elements in the rest of the document. discussion of all the elements in the rest of the document.
The desirable features for a large-scale measurement systems we are The desirable features for a large-scale measurement systems we are
designing for are: designing for are:
o Standardised - in terms of the Measurement Tasks that they o Standardised - in terms of the Measurement Tasks that they
perform, the components, the data models and protocols for perform, the components, the data models and protocols for
transferring information between the components. Amongst other transferring information between the components. Amongst other
things, standardisation enables meaningful comparisons of things, standardisation enables meaningful comparisons of
measurements made of the same metric at different times and measurements made of the same metric at different times and
places, and enables the operator of a measurement system to buy places, and provides the operator of a measurement system with a
the various components from different vendors. Today's systems criteria for evaluation of the different solutions that can be
are proprietary in some or all of these aspects. used for various purposes including buying decisions (such as
buying the various components from different vendors). Today's
systems are proprietary in some or all of these aspects.
o Large-scale - [I-D.ietf-lmap-use-cases] envisages Measurement o Large-scale - [I-D.ietf-lmap-use-cases] envisages Measurement
Agents in every home gateway and edge device such as set-top-boxes Agents in every home gateway and edge device such as set-top-boxes
and tablet computers. It is expected that a measurement system and tablet computers. It is expected that a measurement system
could easily encompass a few hundred thousand Measurement Agents. could easily encompass a few hundred thousand Measurement Agents.
Existing systems have up to a few thousand MAs (without judging Existing systems have up to a few thousand MAs (without judging
how much further they could scale). how much further they could scale).
o Diversity - a measurement system should handle different types of o Diversity - a measurement system should handle different types of
Measurement Agent - for example Measurement Agents may come from Measurement Agent - for example Measurement Agents may come from
different vendors, be in wired and wireless networks and be on different vendors, be in wired and wireless networks, have
devices with IPv4 or IPv6 addresses. different Measurement Task capabilities and be on devices with
IPv4 or IPv6 addresses.
2. Outline of an LMAP-based measurement system 2. Outline of an LMAP-based measurement system
Figure 1 shows the main components of a measurement system, and the Figure 1 shows the main components of a measurement system, and the
interactions of those components. Some of the components are outside interactions of those components. Some of the components are outside
the scope of LMAP. In this section we provide an overview of the the scope of LMAP. In this section we provide an overview of the
whole measurement system and we introduce the main terms needed for whole measurement system and we introduce the main terms needed for
the LMAP framework. The new terms are capitalized. In the next the LMAP framework. The new terms are capitalised. In the next
section we provide a terminology section with a compilation of all section we provide a terminology section with a compilation of all
the LMAP terms and their definition. The subsequent sections study the LMAP terms and their definition.
the LMAP components in more detail.
A Measurement Task measures some performance or reliability Metric of The main work of the LMAP working group is to define the Control
interest. An Active Measurement Task involves either a Measurement Protocol between the Controller and MA, and the Report Protocol
Agent (MA) injecting Active Measurement Traffic into the network between the MA and Collector. Section 4 onwards considers the LMAP
destined for a Measurement Peer, and/or a Measurement Peer sending components in more detail.
Active Measurement Traffic to a MA; one of them measures some
parameter associated with the transfer of the packet(s). A Passive
Measurement Task involves only a MA, which simply observes existing
traffic - for example, it could simply count bytes or it might
calculate the average loss for a particular flow.
It is very useful to standardise Measurement Methods (a Measurement The MA performs Measurement Tasks. The MAs are pieces of code that
Method is a generalisation of a Measurement Task), so that it is can be executed in specialised hardware (hardware probe) or on a
general-purpose device (like a PC or mobile phone). A device with a
Measurement Agent may have multiple interfaces (WiFi, Ethernet, DSL,
fibre, etc.) and the Measurement Tasks may specify any one of these.
Measurement Tasks may be Active (the MA generates Active Measurement
Traffic and measures some metric associated with its transfer),
Passive (the MA observes user traffic), or some hybrid form of the
two.
The MA is managed by a Controller using the Control Protocol. The MA
receives Instructions from the Controller about which Measurement
Tasks it should perform and when. For example the Controller may
instruct a MA at a home gateway: "Count the number of TCP SYN packets
observed in a 1 minute interval; repeat every hour at xx.05 +
Unif[0,180] seconds". The Measurement Schedule determines when the
Measurement Tasks are executed. The Controller also manages a MA by
instructing it how to report the Measurement Results, for example:
"Report results once a day in a batch at 4am + Unif[0,180] seconds;
if the end user is active then delay the report 5 minutes". The
Report Schedule determines when the Reports are uploaded to the
Collector. The Measurement chedule and Report Schedule can define
one-off (non-recurring) actions ("Do measurement now", "Report as
soon as possible"), as well as recurring ones.
The Collector accepts a Report from a MA with the Measurement Results
from its Measurement Tasks. It then provides the Results to a
repository (see below).
Some Measurement Tasks involve several MAs acting in a coordinated
fashion. This coordination is achieved by the Controller instructing
the multiple MAs in a coherent manner. In some Measurement Tasks the
MA(s) is assisted by one or more network entities that are not
managed by the Controller. The entities that helps the MA in the
Measurement Tasks but are not managed by the Controller are called
Measurement Peers (MPs). For example consider the case of a "ping"
Measurement Task, to measure the round trip delay between the MA and
a given ICMP ECHO responder in the Internet. In this case, the
responder is the Measurement Peer. The ICMP ECHO request and ICMP
ECHO Requests and Replies flowing between the MA and the MP is called
Active Measurement Traffic. The Appendix has some other examples of
possible arrangements of Measurement Agents and Peers.
A Measurement Method defines how to measure a Metric of interest. It
is very useful to standardise Measurement Methods, so that it is
meaningful to compare measurements of the same Metric made at meaningful to compare measurements of the same Metric made at
different times and places. It is also useful to define a registry different times and places. It is also useful to define a registry
for commonly-used Metrics [I-D.bagnulo-ippm-new-registry-independent] for commonly-used Metrics [I-D.manyfolks-ippm-metric-registry] so
so that a Measurement Method can be referred to simply by its that a Measurement Method can be referred to simply by its identifier
identifier in the registry. The Measurement Methods and registry in the registry. The Measurement Methods and registry will hopefully
will hopefully be referenced by other standards organisations. be referenced by other standards organisations.
In order for a Measurement Agent and a Measurement Peer to execute an A Measurement Task is a specific instantiation of a Measurement
Active Measurement Task, they exchange Active Measurement Traffic. Method.It generates a Measurement Result. An Active Measurement Task
The protocols used for the Active Measurement Traffic is out of the involves either a Measurement Agent (MA) injecting Active Measurement
scope of the LMAP WG and falls within the scope of other IETF WGs Traffic into the network destined for a Measurement Peer or for
such as IPPM. another Measurement Agent, and/or a Measurement Peer (or another
Measurement Agent) sending Active Measurement Traffic to a MA; one of
them measures some parameter associated with the transfer of the
packet(s). A Passive Measurement Task involves a MA simply observing
existing traffic - for example, it could count bytes or it might
calculate the average loss for a particular flow.
In order for a Measurement Agent and a Measurement Peer (or another
Measurement Agent) to execute an Active Measurement Task, they
exchange Active Measurement Traffic. The protocols used for the
Active Measurement Traffic are out of the scope of the LMAP WG; they
fall within the scope of other IETF WGs such as IPPM.
For Measurement Results to be truly comparable, as might be required For Measurement Results to be truly comparable, as might be required
by a regulator, not only do the same Measurement Methods need to be by a regulator, not only do the same Measurement Methods need to be
used but also the set of Measurement Tasks should follow a similar used but also the set of Measurement Tasks should follow a similar
Measurement Schedule and be of similar number. The details of such a Measurement Schedule and be of similar number. The details of such a
characterisation plan are beyond the scope of work in IETF although characterisation plan are beyond the scope of work in IETF although
certainly facilitated by IETF's work. certainly facilitated by IETF's work.
The next components we consider are the Measurement Agent (MA),
Controller and Collector. The main work of the LMAP working group is
to define the Control Protocol between the Controller and MA, and the
Report Protocol between the MA and Collector. Section 4 onwards
considers the LMAP components in more detail; here we introduce them.
The Controller manages a MA by instructing it which Measurement Tasks
it should perform and when. For example it may instruct a MA at a
home gateway: "Run the 'download speed test' with the Measurement
Peer at the end user's first IP point in the network; if the end user
is active then delay the test and re-try 1 minute later, with up to 3
re-tries; repeat every hour at xx.05 + Unif[0,180] seconds". The
Controller also manages a MA by instructing it how to report the
Measurement Results, for example: "Report results once a day in a
batch at 4am + Unif[0,180] seconds; if the end user is active then
delay the report 5 minutes". These are called the Measurement and
Report Schedule. As well as periodic Measurement Tasks, a Controller
can initiate a one-off (non-recurring) Measurement Task ("Do
measurement now", "Report as soon as possible").
The Collector accepts a Report from a MA with the results from its
Measurement Tasks. It may also do some post-processing on the
results, for instance to eliminate outliers, as they can severely
impact the aggregated results.
Finally we introduce several components that are out of scope of the Finally we introduce several components that are out of scope of the
LMAP WG and will be provided through existing protocols or LMAP WG and will be provided through existing protocols or
applications. They affect how the measurement system uses the applications. They affect how the measurement system uses the
Measurement Results and how it decides what set of Measurement Tasks Measurement Results and how it decides what set of Measurement Tasks
to perform. to perform.
The MA needs to be bootstrapped with initial details about its The MA needs to be bootstrapped with initial details about its
Controller, including authentication credentials. The LMAP WG Controller, including authentication credentials. The LMAP WG
considers the bootstrap process, since it affects the Information considers the bootstrap process, since it affects the Information
Model. However, it does not define a bootstrap protocol, since it is Model. However, it does not define a bootstrap protocol, since it is
likely to be technology specific and could be defined by the likely to be technology specific and could be defined by the
Broadband Forum, CableLabs or IEEE depending on the device. Possible Broadband Forum, CableLabs or IEEE depending on the device. Possible
protocols are SNMP, NETCONF or (for Home Gateways) CPE WAN Management protocols are SNMP, NETCONF or (for Home Gateways) CPE WAN Management
Protocol (CWMP) from the Auto Configuration Server (ACS) (as Protocol (CWMP) from the Auto Configuration Server (ACS) (as
specified in TR-069). specified in TR-069 [TR-069]).
A Subscriber parameter database contains information about the line, A Subscriber parameter database contains information about the line,
such as the customer's broadband contract (perhaps 2, 40 or 80Mb/s), such as the customer's broadband contract (perhaps 2, 40 or 80Mb/s),
the line technology (DSL or fibre), the time zone where the MA is the line technology (DSL or fibre), the time zone where the MA is
located, and the type of home gateway and MA. These parameters are located, and the type of home gateway and MA. These parameters are
already gathered and stored by existing operations systems. They may already gathered and stored by existing operations systems. They may
affect the choice of what Measurement Tasks to run and how to affect the choice of what Measurement Tasks to run and how to
interpret the Measurement Results. For example, a download test interpret the Measurement Results. For example, a download test
suitable for a line with an 80Mb/s contract may overwhelm a 2Mb/s suitable for a line with an 80Mb/s contract may overwhelm a 2Mb/s
line. line.
A results repository records all Measurement Results in an equivalent A results repository records all Measurement Results in an equivalent
form, for example an SQL database, so that they can easily be form, for example an SQL database, so that they can easily be
accessed by the data analysis tools. The data analysis tools also accessed by the data analysis tools.
need to understand the Subscriber's service information, for example
the broadband contract.
The data analysis tools receive the results from the Collector or via The data analysis tools receive the results from the Collector or via
the Results repository. They might visualise the data or identify the Results repository. They might visualise the data or identify
which component or link is likely to be the cause of a fault or which component or link is likely to be the cause of a fault or
degradation. This information could help the Controller decide what degradation. This information could help the Controller decide what
follow-up Measurement Task to perform in order to diagnose a fault. follow-up Measurement Task to perform in order to diagnose a fault.
The data analysis tools also need to understand the Subscriber's
The operator's OAM (Operations, Administration, and Maintenance) uses service information, for example the broadband contract.
the results from the tools.
^ ^
| |
Active IPPM Active +-------------+ IPPM
+---------------+ Measurement +-------------+ Scope +---------------+ Measurement | Measurement | Scope
+------->| Measurement |<------------>| Measurement | v | Measurement |<------------>| Peer | |
| | Agent | Traffic | Peer | ^ | Agent | Traffic +-------------+ v
| +---------------+ +-------------+ | +------->| | ^
| +---------------+ |
| ^ | | | ^ | |
| Instruction | | Report | | Instruction | | Report |
| | +-----------------+ | | | +-----------------+ |
| | | | | | | |
| | v LMAP | | v LMAP
| +------------+ +------------+ Scope | +------------+ +------------+ Scope
| | Controller | | Collector | | | | Controller | | Collector | |
| +------------+ +------------+ v | +------------+ +------------+ v
| ^ ^ | ^ | ^ ^ | ^
| | | | | | | | | |
skipping to change at page 8, line 41 skipping to change at page 8, line 42
Figure 1: Schematic of main elements of an LMAP-based Figure 1: Schematic of main elements of an LMAP-based
measurement system measurement system
(showing the elements in and out of the scope of the LMAP WG) (showing the elements in and out of the scope of the LMAP WG)
3. Terminology 3. Terminology
This section defines terminology for LMAP. Please note that defined This section defines terminology for LMAP. Please note that defined
terms are capitalized. terms are capitalized.
Active Measurement Method (Task): A type of Measurement Method (Task) Active Measurement Method (Task): A Measurement Method (Task) in
that involves a Measurement Agent and a Measurement Peer (or possibly which a Measurement Agent creates or receives Active Measurement
Peers), where either the Measurement Agent or the Measurement Peer Traffic, by coordinating with one or more other Measurement Agents or
injects Active Measurement Traffic into the network destined for the Measurement Peers using protocols outside LMAP's scope.
other, and which involves one of them measuring some performance or
reliability parameter associated with the transfer of the traffic.
Active Measurement Traffic: the packet(s) generated by the Active Measurement Traffic: the packet(s) generated in order to
Measurement Agent and/or the Measurement Peer, as part of an Active execute an Active Measurement Task.
Measurement Task.
Bootstrap: A process that initialises a Measurement Agent with the Bootstrap: A process that integrates a Measurement Agent into a
information necessary to be integrated into a measurement system. measurement system.
Capabilities: Information about the Measurement Methods that the MA Capabilities: Information about the Measurement Methods that the MA
can perform and the device hosting the MA, for example its interface can perform and the device hosting the MA, for example its interface
type and speed and its IP address. type and speed, but not dynamic information.
Channel: an Instruction Channel, Report Channel or MA-to-Controller Channel: A bi-directional logical connection that is defined by a
Channel specific Controller and MA, or Collector and MA, plus associated
security.
Collector: A function that receives a Report from a Measurement Collector: A function that receives a Report from a Measurement
Agent. Agent.
Composite Metric: A Metric that is a combination of other Metrics, Controller: A function that provides a Measurement Agent with its
and/or a combination of the same Metric measured over different parts Instruction.
of the network or at different times.
Controller: A function that provides a Measurement Agent with
Instruction(s).
Control Channel: a communications channel between a Controller and a Control Channel: a Channel between a Controller and a MA over which
MA, which is defined by a specific Controller, MA and associated Instruction Messages and Capabilities and Failure information are
security, and over which Instructions are sent. sent.
Control Protocol: The protocol delivering Instruction(s) from a Control Protocol: The protocol delivering Instruction(s) from a
Controller to a Measurement Agent. It also delivers Failure Controller to a Measurement Agent. It also delivers Failure
Information and Capabilities Information from the Measurement Agent Information and Capabilities Information from the Measurement Agent
to the Controller. to the Controller.
Cycle-ID: (optional) A tag that is sent by the Controller in an Cycle-ID: A tag that is sent by the Controller in an Instruction and
Instruction and echoed by the MA in its Report. The same Cycle-ID is echoed by the MA in its Report. The same Cycle-ID is used by several
used by several MAs that use the same Measurement Method with the MAs that use the same Measurement Method with the same Input
same Input Parameters. Hence the Cycle-ID allows the Collector to Parameters. Hence the Cycle-ID allows the Collector to easily
easily identify Measurement Results that should be comparable. identify Measurement Results that should be comparable.
Data Model: The implementation of an Information Model in a Data Model: The implementation of an Information Model in a
particular data modelling language. particular data modelling language [RFC3444].
Data Transfer Method: The process whereby: a Controller transfers
information over a Control Channel to a MA; or a MA transfers
information over a Control Channel to a Controller; or a MA transfers
information over a Report Channel to a Collector; the generalisation
of a Data Transfer Task.
Data Transfer Task: The act consisting of the (single) operation of a
Data Transfer Method at a particular time.
Environmental Constraint: A parameter that is measured as part of the Environmental Constraint: A parameter that is measured as part of the
Measurement Task, its value determining whether the rest of the Measurement Task, its value determining whether the rest of the
Measurement Task proceeds. Measurement Task proceeds.
Failure Information: Information about the MA's failure to action or Failure Information: Information about the MA's failure to action or
execute an Instruction, whether concerning Measurement Tasks or execute an Instruction, whether concerning Measurement Tasks or
Reporting. Reporting.
Group-ID: (optional) An identifier of a group of MAs. Group-ID: An identifier of a group of MAs.
Information Model: The protocol-neutral definition of the semantics Information Model: The protocol-neutral definition of the semantics
of the Instructions, the Report, the status of the different elements of the Instructions, the Report, the status of the different elements
of the measurement system as well of the events in the system. of the measurement system as well of the events in the system
[RFC3444].
Input Parameter: A parameter whose value is left open by the Input Parameter: A parameter whose value is left open by the
Measurement Method and is set to a specific value in a Measurement Measurement Method and is set to a specific value in a Measurement
Task. Altering the value of an Input Parameter does not change the Task. Altering the value of an Input Parameter does not change the
fundamental nature of the Measurement Method. fundamental nature of the Measurement Method.
Instruction: The description of Measurement Tasks to perform and the Instruction: The description of Measurement Tasks for a MA to perform
details of the Report to send. The Instruction is sent by a and the details of the Report for it to send. It is the collective
Controller to a Measurement Agent. description of the Measurement Task configurations, the configuration
of the Report Channel(s), the configuration of Data Transfer Tasks,
the configuration of the Measurement Schedules, and the details of
any suppression.
MA-to-Controller Channel: a communications channel between a MA and a Instruction Message: The message that carries an Instruction from a
Controller, which is defined by a specific Controller, MA and Controller to a Measurement Agent.
associated security, and over which Capabilities and Failure
Information is sent.
Measurement Agent (MA): The function that receives Instructions from Measurement Agent (MA): The function that receives Instruction
a Controller, performs Measurement Tasks (perhaps in concert with a Messages from a Controller and operates the Instruction by executing
Measurement Peer) and reports Measurement Results to a Collector. Measurement Tasks (using protocols outside LMAP's scope and perhaps
in concert with one or more other Measurement Agents or Measurement
Peers) and (if part of the Instruction) by reporting Measurement
Results to a Collector or Collectors.
Measurement Agent Identifier (MA-ID): a UUID [RFC4122], which is Measurement Agent Identifier (MA-ID): a UUID [RFC4122] that
configured as part of the Bootstrapping and included in a identifies a particular MA and is configured as part of the
Capabilities message, Failure Information message and optionally in a Bootstrapping process.
Report.
Measurement Method: The process for assessing the value of a Metric; Measurement Method: The process for assessing the value of a Metric;
the process of measuring some performance or reliability parameter; the process of measuring some performance or reliability parameter
the generalisation of a Measurement Task. associated with the transfer of traffic; the generalisation of a
Measurement Task.
Measurement Peer: The function that receives control messages and Measurement Peer (MP): The function that assists a Measurement Agent
Active Measurement Traffic from a Measurement Agent and may reply to with Measurement Tasks and does not have an interface to the
the Measurement Agent as defined by the Active Measurement Method. Controller or Collector.
Measurement Result: The output of a single Measurement Task (the Measurement Result: The output of a single Measurement Task (the
value obtained for the parameter of interest or Metric). value obtained for the parameter of interest or Metric).
Measurement Schedule: the schedule for performing Measurement Tasks. Measurement Schedule: The schedule for performing Measurement Tasks.
Measurement Suppression: a type of Instruction that temporarily stops
(suppresses) Active Measurement Tasks.
Measurement Task: The act that yields a single Measurement Result; Measurement Task: The act that consistsof the single operation of the
the act consisting of the (single) operation of the Measurement Measurement Method at a particular time and with all its Input
Method at a particular time and with all its parameters set to Parameters set to specific values.
specific values.
Metric: The quantity related to the performance and reliability of Metric: The quantity related to the performance and reliability of
the network that we'd like to know the value of, and that is the network that we'd like to know the value of, and that is
carefully specified. carefully specified.
Passive Measurement Method (Task): A Measurement Method (Task) in Passive Measurement Method (Task): A Measurement Method (Task) in
which a Measurement Agent observes existing traffic but does not which a Measurement Agent observes existing traffic but does not
inject Active Measurement Traffic. inject Active Measurement Traffic.
Report: The Measurement Results and other associated information (as Report: The set of Measurement Results and other associated
defined by the Instruction). The Report is sent by a Measurement information (as defined by the Instruction). The Report is sent by a
Agent to a Collector. Measurement Agent to a Collector.
Report Channel: a communications channel between a MA and a Report Channel: a communications channel between a MA and a
Collector, which is defined by a specific MA, Collector, Report Collector, which is defined by a specific MA, Collector, Report
Schedule and associated security, and over which Reports are sent. Schedule and associated security, and over which Reports are sent.
Report Protocol: The protocol delivering Report(s) from a Measurement Report Protocol: The protocol delivering Report(s) from a Measurement
Agent to a Collector. Agent to a Collector.
Report Schedule: the schedule for sending one or more Reports to a Report Schedule: the schedule for sending Reports to a Collector.
Collector.
Subscriber: An entity (associated with one or more users) that is Subscriber: An entity (associated with one or more users) that is
engaged in a subscription with a service provider. The Subscriber is engaged in a subscription with a service provider. The Subscriber is
allowed to subscribe and un-subscribe services, and to register a allowed to subscribe and un-subscribe services, and to register a
user or a list of users authorized to enjoy these services. [Q1741] user or a list of users authorized to enjoy these services. [Q1741].
Both the Subscriber and service provider are allowed to set the Both the Subscriber and service provider are allowed to set the
limits relative to the use that associated users make of subscribed limits relative to the use that associated users make of subscribed
services. services.
Suppression: the temporary cessation of Active Measurement Tasks.
4. Constraints 4. Constraints
The LMAP framework makes some important assumptions, which constrain The LMAP framework makes some important assumptions, which constrain
the scope of the work to be done. the scope of the work to be done.
4.1. Measurement system is under the direction of a single organisation 4.1. Measurement system is under the direction of a single organisation
In the LMAP framework, the measurement system is under the direction In the LMAP framework, the measurement system is under the direction
of a single organisation that is responsible both for the data and of a single organisation that is responsible for any impact that
the quality of experience delivered to its users. Clear measurements have on a user's quality of experience and privacy.
responsibility is critical given that a misbehaving large-scale Clear responsibility is critical given that a misbehaving large-scale
measurement system could potentially harm user experience, user measurement system could potentially harm user experience, user
privacy and network security. privacy and network security.
However, the components of an LMAP measurement system can be deployed However, the components of an LMAP measurement system can be deployed
in administrative domains that are not owned by the measuring in administrative domains that are not owned by the measuring
organisation. Thus, the system of functions deployed by a single organisation. Thus, the system of functions deployed by a single
organisation constitutes a single LMAP domain which may span organisation constitutes a single LMAP domain which may span
ownership or other administrative boundaries. ownership or other administrative boundaries.
4.2. Each MA may only have a single Controller at any point in time 4.2. Each MA may only have a single Controller at any point in time
skipping to change at page 12, line 43 skipping to change at page 12, line 47
An LMAP system goes through the following phases: An LMAP system goes through the following phases:
o a bootstrapping process before the MA can take part in the other o a bootstrapping process before the MA can take part in the other
three phases three phases
o a Control Protocol, which delivers an Instruction from a o a Control Protocol, which delivers an Instruction from a
Controller to a MA, detailing what Measurement Tasks the MA should Controller to a MA, detailing what Measurement Tasks the MA should
perform and when, and how it should report the Measurement Results perform and when, and how it should report the Measurement Results
o the actual Measurement Tasks are performed. An Active Measurement o the actual Measurement Tasks, which measure some performance or
Task involves sending Active Measurement Traffic between the reliability parameter(s) associated with the transfer of packets.
Measurement Agent and a Measurement Peer, whilst a Passive The LMAP WG does not define Measurement Methods, however the IPPM
Measurement Task involves (only) the Measurement Agent observing WG does.
existing user traffic. The LMAP WG does not define Measurement
Methods, however the IPPM WG does.
o a Report Protocol, which delivers a Report from the MA to a o a Report Protocol, which delivers a Report from the MA to a
Collector. The Report contains the Measurement Results. Collector. The Report contains the Measurement Results.
In the diagrams the following convention is used: The diagrams show the various LMAP messages and usesthe following
convention:
o (optional): indicated by round brackets o (optional): indicated by round brackets
o [potentially repeated]: indicated by square brackets o [potentially repeated]: indicated by square brackets
The protocol model is closely related to the Information Model The protocol model is closely related to the Information Model
[I-D.burbridge-lmap-information-model], which is the abstract [I-D.burbridge-lmap-information-model], which is the abstract
definition of the information carried by the protocol model. The definition of the information carried by the protocol model. The
purpose of both is to provide a protocol and device independent view, purpose of both is to provide a protocol and device independent view,
which can be implemented via specific protocols. The LMAP WG will which can be implemented via specific protocols. The LMAP WG will
define a specific Control Protocol and Report Protocol, but others define a specific Control Protocol and Report Protocol, but others
could be defined by other standards bodies or be proprietary. could be defined by other standards bodies or be proprietary.
However it is important that they all implement the same Information However it is important that they all implement the same Information
Model and protocol model, in order to ease the definition, operation Model and protocol model, in order to ease the definition, operation
and interoperability of large-scale measurement systems. and interoperability of large-scale measurement systems.
The diagrams show the various LMAP messages and Section 5.5 considers
how they could be mapped onto an underlying transport protocol.
5.1. Bootstrapping process 5.1. Bootstrapping process
The primary purpose of bootstrapping is to enable the MA and The primary purpose of bootstrapping is to enable a MA to be
Controller to be integrated into a measurement system. In order to integrated into a measurement system. The MA retrieves information
do that, the MA needs to retrieve information about itself (like its about itself (like its identity in the measurement system) and about
identity in the measurement system), about the Controller, as well as the Controller, the Controller learns information about the MA, and
security information (such as certificates and credentials). they learn about security information to communicate (such as
certificates and credentials).
+--------------+
| Measurement |
| Agent |
+--------------+
(initial Controller details:
address or FQDN, ->
security credentials)
+-----------------+ Whilst the LMAP WG considers the bootstrapping process, it is out of
| initial | scope to define a bootstrap mechanism, as it depends on the type of
| Controller | device and access.
+-----------------+
<- (register)
Controller details: As a result of the bootstrapping process the MA learns the following
address or FQDN, -> information:
security credentials
+-----------------+ o its identifier, MA-ID
| |
| Controller |
+-----------------+
<- register
MA-ID, (Group-ID), ->
Control Channel,
(Suppression Channel),
MA-to-Controller Channel
The MA knows how to contact a Controller through some device /access o (optionally) a Group-ID. A Group-ID would be shared by several
specific mechanism. For example, this could be in the firmware, MAs and could be useful for privacy reasons, for instance to
downloaded, manually configured or via a protocol like TR-069. The hinder tracking of a mobile device
Controller could either be the one that will send it Instructions or
else an initial Controller (whose details may be statically
configured). The role of an initial Controller is simply to inform
the MA how to contact its actual Controller, for example its FQDN
(Fully Qualified Domain Name) [RFC1035].
The MA learns its identifier (MA-ID). It may also be told a Group-ID o the Control Channel, which is defined by:
and whether to include the MA-ID as well as the Group-ID in its
Reports. A Group-ID would be shared by several MAs and could be
useful for privacy reasons, for instance to hinder tracking of a
mobile device.
The MA is also told about the Control Channel over which it will * the address of the Controller (such as its FQDN (Fully
receive Instructions from the Controller, in particular the Qualified Domain Name) [RFC1035])
associated security information, for example to enable the MA to
decrypt the Instruction. Optionally any Suppression messages can be
sent over a different Channel. The MA is also informed about the MA-
to-Controller Channel, over which the MA can tell the Controller
about its Capabilities and any Failure Information. This consists of
the address of the Controller, for instance its URL, and security
details for MA-to-Controller messages.
The MA may tell the Controller its Capabilities, in particular the * security information (for example to enable the MA to decrypt
Measurement Methods it can perform. the Instruction Message and encrypt messages sent to the
Controller)
If the device with the MA re-boots, then the MA needs to re-register, * the name of this Control Channel
so that it can receive a new Instruction. To avoid a "mass calling
event" after a widespread power restoration affecting many MAs, it is
sensible for an MA to pause for a random delay (perhaps in the range
of one minute or so) before re-registering.
Whilst the LMAP WG considers the bootstrapping process, it is out of The details of the bootstrapping process are device /access specific.
scope to define a bootstrap mechanism, as it depends on the type of For example, the information could be in the firmware, manually
device and access. configured or transferred via a protocol like TR-069. There may be a
multi-stage process where the MA contacts the device at a 'hard-
coded' address, which replies with the boostrapping information.
5.2. Control Protocol 5.2. Control Protocol
The primary purpose of the Control Protocol is to allow the The primary purpose of the Control Protocol is to allow the
Controller to configure a Measurement Agent with an Instruction about Controller to configure a Measurement Agent with an Instruction about
what Measurement Tasks to do, when to do them, and how to report the what Measurement Tasks to do, when to do them, and how to report the
Measurement Results. The Measurement Agent then acts on the Measurement Results (Section 5.2.1). The Measurement Agent then acts
Instruction autonomously. on the Instruction autonomously. The Control Protocol also enables
the MA to inform the Controller about its Capabilities and any
Failures (Section 5.2.2).
+-----------------+ +-------------+ 5.2.1. Instruction
| | | Measurement |
| Controller |===================================| Agent |
+-----------------+ +-------------+
(Capabilities request) -> The Instruction is the description of the Measurement Tasks for a
<- Capabilities Measurement Agent to do and the details of the Measurement Reports
ACK -> for it to send. In order to update the Instruction the Controller
uses a Data Transfer Task to send an Instruction Message over the
Control Channel.
Instruction: +-----------------+ +-------------+
[(Measurement Task (Input Parameters)), -> | | | Measurement |
(Measurement Schedule), | Controller |======================================| Agent |
(Report Channel(s))] +-----------------+ +-------------+
<- ACK
<- Failure Information: Instruction: ->
[reason] [(Measurement Task configuration(
ACK -> [Input Parameter],
The Controller needs to know the Capabilities of the MA, and in (interface),
particular what Measurement Methods it supports, so that it can (Cycle-ID))),
correctly instruct the MA. It is possible that the Controller knows (Report Channel),
the MA's Capabilities via some mechanism beyond the scope of LMAP, (Data Transfer Task),
such as a device-specific protocol. In LMAP, the MA can inform the (Measurement Schedule),
Controller about its Capabilities. This message could be sent in (Suppression information)]
several circumstances: when the MA first communicates with a <- Response(details)
Controller; when the MA becomes capable of a new Measurement Method;
when requested by the Controller (for example, if the Controller
forgets what the MA can do or otherwise wants to resynchronize what
it knows about the MA). Note that Capabilities do not include
dynamic information like the MA's currently unused CPU, memory or
battery life.
A single Instruction message contains one, two, three or all four of The Instruction defines the following:
the following elements:
o configuration of all the Measurement Tasks, each of which needs: o the Measurement Task configurations, each of which needs:
* the Measurement Method, specified as a URN to a registry entry. * the Measurement Method, specified as a URN to a registry entry.
The registry could be defined by the IETF The registry could be defined by the IETF
[I-D.bagnulo-ippm-new-registry-independent], locally by the [I-D.manyfolks-ippm-metric-registry], locally by the operator
operator of the measurement system or perhaps by another of the measurement system or perhaps by another standards
standards organisation. organisation.
* any Input Parameters that need to be set for the Measurement * any Input Parameters that need to be set for the Measurement
Method, such as the address of the Measurement Peer Method, such as the address of the Measurement Peer (or other
Measurement Agent) that are involved in an Active Measurement
Task
* if the device with the MA has multiple interfaces, then the * if the device with the MA has multiple interfaces, then the
interface to use interface to use (if not defined, then the default interface is
used)
* optionally, a Cycle-ID * optionally, a Cycle-ID (a tag that may help the data analysis
tools identify Measurement Results that should be comparable)
* a name for this Measurement Task configuration * a name for this Measurement Task configuration
o configuration of all the Report Channels, each of which needs: o configuration of the Report Channels, each of which needs:
* the address of the Collector, for instance its URL * the address of the Collector, for instance its URL
* the timing of when to report Measurement Results, for example * security for this Report Channel, for example the X.509
every hour or immediately
* security for sending the Report, for example the X.509
certificate certificate
* a name for this Report Channel * a name for this Report Channel
o the set of periodic Measurement Schedules, each of which needs: o configuration of the Data Transfer Tasks, each of which needs:
* the name of one or several Measurement Task configurations * the name of the Channel to use
* the timing of when the Measurement Tasks are to be performed. * the timing of when to operate this Data Transfer Task
Possible types of timing are periodic and calendar-based
periodic
* the name of a Report Channel or Channels on which to report the * whether to include the MA-ID &/or Group-ID in a Measurement
Measurement Results Report
* a name for this Measurement Schedule * a name for this Data Transfer Task
o the set of one-off Measurement Schedules, each of which needs the A Data Transfer Task may concern the reporting of Measurement
same items as for a periodic Measurement Schedule, except that the Results (when the timing could be every hour or immediately, for
possible types of timing are one-off immediate and one-off at a instance). Alternatively, a Data Transfer Task may concern the MA
future time. informing the Controller about its Capabilities or any Failures.
A single Instruction message contains one, two, three or all four of o configuration of the Measurement Schedules, each of which needs:
the above elements. This allows the different elements to be updated
independently at different times and intervals, for example it is
likely that the periodic Measurement Schedule will be updated more
often than the other elements.
Note that an Instruction message replaces (rather than adds to) those * the name of one or several Measurement Task configurations
elements that it includes. For example, if the message includes
(only) a periodic Measurement Schedule, then that replaces the old
periodic Measurement Schedule but does not alter the configuration of
the Measurement Tasks and Report Channels.
Periodic Measurement Schedules contain the name of one or several * the timing of when the Measurement Tasks are to be performed.
Measurement Task configurations that are to be carried out on a Possible types of timing are periodic, calendar-based periodic,
recurring basis, whilst one-off Measurement Schedules contain non- one-off immediate and one-off at a future time
recurring Measurement Tasks. One-off and periodic Measurement
Schedules are kept separate so that the Controller can instruct the
MA to perform an ad hoc Measurement Task (for instance to help
isolate a fault) without having to re-notify the MA about the
periodic Measurement Schedule.
Note that the Instruction informs the MA; the Control Protocol does * the name of a Data Transfer Task or Tasks on which to report
not allow the MA to negotiate, as this would add complexity to the the Measurement Results
MA, Controller and Control Protocol for little benefit.
The MA can inform the Controller about a Failure. There are two * a name for this Measurement Schedule
broad categories of failure: (1) the MA cannot action the Instruction
(for example, it doesn't include a parameter that is mandatory for
the requested Measurement Method; or it is missing details of the
target Collector). (2) the MA cannot execute the Measurement Task or
deliver the Report (for example, the MA unexpectedly has no spare CPU
cycles; or the Collector is not responding). Note that it is not
considered a failure if a Measurement Task (correctly) doesn't start;
for example if the MA detects cross-traffic, this is reported to the
Collector in the normal manner. Note also that the MA does not
inform the Controller about normal operation of its Measurement Tasks
and Reports.
In the Figure, ACK means that the message has been delivered o Suppression information, if any (see Section 5.2.1.1)
successfully.
Finally, note that the MA doesn't do a 'safety check' with the A single Instruction Message may contain some or all of the above
Controller (that it should still continue with the requested parts. The finest level of granularity possible in an Instruction
Measurement Tasks) - nor does it inform the Controller about Message is determined by the implementation and operation of the
Measurement Tasks starting and stopping. It simply carries out the Control Protocol. For example, a single Instruction Message may be
Measurement Tasks as instructed, unless it gets an updated able to add or update an individual Measurement Schedule - or it may
Instruction. only be able to update the complete set of Measurement Schedules; a
single Instruction Message may be able to update both Measurement
Schedules and Measurement Task configurations - or only one at a
time; and so on.
The LMAP WG will define a Control Protocol and its associated Data The MA informs the Controller that it has successfully understood the
Model that implements the Protocol & Information Model. This may be Instruction Message, or that it cannot action the Instruction - for
a simple instruction-response protocol. example, if it doesn't include a parameter that is mandatory for the
requested Measurement Method, or it is missing details of the target
Collector.
5.2.1. Measurement Suppression The Instruction Message instructs the MA; the Control Protocol does
not allow the MA to negotiate, as this would add complexity to the
MA, Controller and Control Protocol for little benefit.
Measurement Suppression is used if the measurement system wants to 5.2.1.1. Suppression
eliminate inessential traffic, because there is some unexpected
network issue for example. The Controller instructs the MA to
temporarily not begin new Active Measurement Tasks. By default,
suppression applies to all Active Measurement Tasks, starts
immediately and continues until an un-suppress message is received.
Optionally the suppress message may include:
o a set of Active Measurement Tasks to suppress; the others are not The Instruction may include Suppression information. Suppression is
suppressed. For example, a particular Measurement Task may be used if the measurement system wants to eliminate inessential
overloading a Measurement Peer. traffic, because there is some unexpected network issue for example.
By default, Suppression means that the MA does not begin any new
Active Measurement Task. The impact on other Measurement Tasks is
not defined by LMAP; since they do not involve the MA creating any
Active Measurement Traffic there is no need to suppress them, however
it may be simpler for an implementation to do so. Also, by default
Suppression starts immediately and continues until an un-suppress
message is received. Optionally the Suppression information may
include:
o a set of Measurement Tasks to suppress; the others are not
suppressed. For example, this could be useful if a particular
Measurement Task is overloading a Measurement Peer.
o a set of Measurement Schedules to suppress; the others are not o a set of Measurement Schedules to suppress; the others are not
suppressed. For example, suppose the measurement system has suppressed. For example, suppose the measurement system has
defined two Schedules, one with the most critical Active defined two Schedules, one with the most critical Measurement
Measurement Tasks and the other with less critical ones that Tasks and the other with less critical ones that create a lot of
create a lot of traffic, then it may only want to suppress the Active Measurement Traffic, then it may only want to suppress the
second. second.
o a start time, at which suppression begins o a start time, at which suppression begins
o an end time, at which suppression ends. o an end time, at which suppression ends
It is not standardised what the impact of Suppression is on:
o Passive Measurement Tasks; since they do not create any Active
Measurement Traffic there is no need to suppress them, however it
may be simpler for an implementation to do so
o on-going Active Measurement Tasks; see Section 5.3 o that the MA should end its on-going Active Measurement Task(s).
Note that Suppression is not intended to permanently stop a Note that Suppression is not intended to permanently stop a
Measurement Task (instead, the Controller should send a new Measurement Task (instead, the Controller should send a new
Measurement Schedule), nor to permanently disable a MA (instead, some Measurement Schedule), nor to permanently disable a MA (instead, some
kind of management action is suggested). kind of management action is suggested).
+-----------------+ +-------------+ +-----------------+ +-------------+
| | | Measurement | | | | Measurement |
| Controller |===================================| Agent | | Controller |===================================| Agent |
+-----------------+ +-------------+ +-----------------+ +-------------+
Suppress: Suppress:
[(Measurement Task), -> [(Measurement Task), ->
(Measurement Schedule), (Measurement Schedule),
start time, end time] start time,
<- ACK end time,
on-going suppressed?]
Un-suppress -> Un-suppress ->
<- ACK
5.3. Starting and stopping Measurement Tasks 5.2.2. Capabilities and Failure information
The LMAP WG is neutral to what the actual Measurement Task is. The The Control Protocol also enables the MA to inform the Controller
WG does not define a generic start and stop process, since the about various information, such as its Capabilities and any Failures,
correct approach depend on the particular Measurement Task; the by the MA operating a Data Transfer Task. It is also possible that a
details are defined as part of each Measurement Method, and hence device-specific mechanism beyond the scope of LMAP is used.
potentially by the IPPM WG. This section provides some general
hints.
Once the MA gets its Measurement and Report Schedules from its Capabilities are information about the MA that the Controller needs
Controller then it acts autonomously, in terms of operation of the to know in order to correctly instruct the MA, such as:
Measurement Tasks and reporting of the result. One implication is
that the MA initiates Measurement Tasks. As an example, for the
common case where the MA is on a home gateway, the MA initiates a
'download speed test' by asking a Measurement Peer to send the file.
Many Active Measurement Tasks begin with a pre-check before the test o the Measurement Methods that the MA supports
traffic is sent. Action could include: o the interfaces that the MA has
o the MA checking that there is no cross-traffic; in other words, a o the version of the MA
check that the user isn't already sending traffic;
o the MA checking with the Measurement Peer that it can handle a new o the version of the hardware, firmware or software of the device
Measurement Task (in case the Measurement Peer is already handling with the MA
many Measurement Tasks with other MAs);
o but not dynamic information like the currently unused CPU, memory
or battery life of the device with the MA.
The MA could do this in response to a request from the Controller
(for example, if the Controller forgets what the MA can do or
otherwise wants to resynchronize what it knows about the MA) or on
its own initiative (for example when the MA first communicates with a
Controller or if it becomes capable of a new Measurement Method).
Another example of the latter case is if the device with the MA re-
boots, then the MA should notify its Controller in case its
Instruction needs to be updated; to avoid a "mass calling event"
after a widespread power restoration affecting many MAs, it is
sensible for an MA to pause for a random delay, perhaps in the range
of one minute or so.
Failure information is sent on the initiative of the MA and concerns
why the MA has been unable to execute a Measurement Task or Data
Transfer Task, for example:
o the Measurement Task failed to run properly because the MA
(unexpectedly) has no spare CPU cycles
o the MA failed record the Measurement Results because it
(unexpectedly) is out of spare memory
o a Data Transfer Task failed to deliver Measurement Results because
the Collector (unexpectedly) is not responding
o but not if a Measurement Task correctly doesn't start. For
example, the first step of some Measurement Methods is for the MA
to check there is no cross-traffic.
Logging information is sent by the MA in response to a request from
the Controller; it concerns how the MA is operating and may help
debugging, for example:
o the last time the MA ran a Measurement Task
o the last time the MA sent a Measurement Report
o the last time the MA received an Instruction Message
o whether the MA is currently Suppressing Measurement Tasks
.
+-----------------+ +-------------+
| | | Measurement |
| Controller |===================================| Agent |
+-----------------+ +-------------+
(Capabilities request) ->
<- Capabilities
<- Failure Information
[reason]
Logging request ->
<- Logging Information
[details]
5.3. Operation of Measurement Tasks
The LMAP WG is neutral to what the actual Measurement Task is. It
does not define Measurement Methods, however the IPPM WG does.
The MA carries out the Measurement Tasks as instructed, unless it
gets an updated Instruction. The MA acts autonomously, in terms of
operation of the Measurement Tasks and reporting of the Results; it
doesn't do a 'safety check' with the Controller to ask whether it
should still continue with the requested Measurement Tasks.
5.3.1. Starting and Stopping Measurement Tasks
The WG does not define a generic start and stop process, since the
correct approach depends on the particular Measurement Task; the
details are defined as part of each Measurement Method. This section
provides some general hints. The MA does not inform the Controller
about Measurement Tasks starting and stopping.
Before sending Active Measurement Traffic the MA may run a pre-check.
Action could include:
o the MA checking that there is no cross-traffic. In other words, a
check that the end-user isn't already sending traffic;
o the MA checking with the Measurement Peer (or other Measurement
Agent involved in the Measurement Task) that it can handle a new
Measurement Task (in case, for example, the Measurement Peer is
already handling many Measurement Tasks with other MAs);
o the first part of the Measurement Task consisting of traffic that o the first part of the Measurement Task consisting of traffic that
probes the path to make sure it isn't overloaded. probes the path to make sure it isn't overloaded;
o the first part of the Measurement Task checking that the device
with the MA has enough resources to execute the Measurement Task
reliably. Note that the designer of the measurement system should
ensure that the device's capabilities are normally sufficient to
comfortably operate the Measurement Tasks.
It is possible that similar checks continue during the Measurement It is possible that similar checks continue during the Measurement
Task, especially one that is long-running and/or creates a lot of Task, especially one that is long-running and/or creates a lot of
Active Measurement Traffic, which may be abandoned whilst in- Active Measurement Traffic, and might lead to it being abandoned
progress. A Measurement Task could also be abandoned in response to whilst in-progress. A Measurement Task could also be abandoned in
a "suppress" message (see Section 5.2.1). Action could include: response to a "suppress" message (see Section 5.2.1). Action could
include:
o For 'upload' tests, the MA not sending traffic o For 'upload' tests, the MA not sending traffic
o For 'download' tests, the MA closing the TCP connection or sending o For 'download' tests, the MA closing the TCP connection or sending
a TWAMP Stop control message [RFC5357]. a TWAMP Stop control message [RFC5357].
The Controller may want a MA to run the same Measurement Task The Controller may want a MA to run the same Measurement Task
indefinitely (for example, "run the 'upload speed' Measurement Task indefinitely (for example, "run the 'upload speed' Measurement Task
once an hour until further notice"). To avoid the MA generating once an hour until further notice"). To avoid the MA generating
traffic forever after a Controller has permanently failed, it is traffic forever after a Controller has permanently failed, it is
suggested that the Measurement Schedule includes a time limit ("run suggested that the Measurement Schedule includes a time limit ("run
the 'upload speed' Measurement Task once an hour for the next 30 the 'upload speed' Measurement Task once an hour for the next 30
days") and that the Measurement Schedule is updated regularly (say, days") and that the Measurement Schedule is updated regularly (say,
every 10 days). every 10 days).
{Comment: It is possible that the set of measurement schedules 5.3.2. Overlapping Measurement Tasks
implies overlapping Measurement Tasks. It is not clear the best
thing to do. Our current suggestion is to leave this to the protocol It is possible that a MA starts a new Measurement Task before another
document.} Measurement Task has completed. This may be intentional (the way
that the measurement system has designed the Measurement Schedules),
but it could also be unintentional - for instance, if a Measurement
Task has a 'wait for X' step which pauses for an unexpectedly long
time. The operator of the measurement system can handle (or not)
overlapping Measurement Tasks in any way they choose - it is a policy
or implementation issue and not the concern of LMAP. Some possible
approaches are: to configure the MA not to begin the second
Measurement Task; to start the second Measurement Task as usual; for
the action to be an Input Parameter of the Measurement Task; and so
on.
It is likely to be important to include in the Measurement Report the
fact that the Measurement Task overlapped with another.
5.4. Report Protocol 5.4. Report Protocol
The primary purpose of the Report Protocol is to allow a Measurement The primary purpose of the Report Protocol is to allow a Measurement
Agent to report its Measurement Results to a Collector, and the Agent to report its Measurement Results to a Collector, along with
context in which they were obtained. the context in which they were obtained.
+-----------------+ +-------------+ +-----------------+ +-------------+
| | | Measurement | | | | Measurement |
| Collector |===================================| Agent | | Collector |===================================| Agent |
+-----------------+ +-------------+ +-----------------+ +-------------+
<- Report: <- Report:
[MA-ID &/or Group-ID, [MA-ID &/or Group-ID],
Measurement Results, [Measurement Result
details of Measurement Task] [details of Measurement Task]]
ACK -> ACK ->
The Report contains: The Report contains:
o the MA-ID or a Group-ID (to anonymise results) o the MA-ID or a Group-ID (to anonymise results)
o the actual Measurement Results, including the time they were o the actual Measurement Results, including the time they were
measured measured
o the details of the Measurement Task (to avoid the Collector having o the details of the Measurement Task (to avoid the Collector having
to ask the Controller for this information later) to ask the Controller for this information later)
The MA sends Reports as defined by the Report Channel in the o perhaps the Subscriber's service parameters (see Section 5.4.1).
The MA sends Reports as defined by the Data Transfer Task in the
Controller's Instruction. It is possible that the Instruction tells Controller's Instruction. It is possible that the Instruction tells
the MA to report the same Results to more than one Collector, or to the MA to report the same Results to more than one Collector, or to
report a different subset of Results to different Collectors. It is report a different subset of Results to different Collectors. It is
also possible that a Measurement Task may create two (or more) also possible that a Measurement Task may create two (or more)
Measurement Results, which could be reported differently (for Measurement Results, which could be reported differently (for
example, one Result could be reported periodically, whilst the second example, one Result could be reported periodically, whilst the second
Result could be an alarm that is created as soon as the measured Result could be an alarm that is created as soon as the measured
value of the Metric crosses a threshold and that is reported value of the Metric crosses a threshold and that is reported
immediately). immediately).
Optionally, a Report is not sent when there are no Measurement Optionally, a Report is not sent when there are no Measurement
Results. Results.
In the initial LMAP Information Model and Report Protocol, for In the initial LMAP Information Model and Report Protocol, for
simplicity we assume that all Measurement Results are reported as-is, simplicity we assume that all Measurement Results are reported as-is,
but allow extensibility so that a measurement system (or perhaps a but allow extensibility so that a measurement system (or perhaps a
second phase of LMAP) could allow a MA to pre-process Measurement second phase of LMAP) could allow a MA to:
Results before it reports them. Potential examples of pre-processing
by the MA are:
o labelling, or perhaps not including, Measurement Results impacted o label, or perhaps not include, Measurement Results impacted by,
by, for instance, cross-traffic or the Measurement Peer being busy for instance, cross-traffic or the Measurement Peer (or other
Measurment Agent) being busy
o not reporting the Measurement Results if the MA believes that they o label Measurement Results obtained by a Measurement Task that
are invalid overlapped with another
o detailing when suppression started and ended o not report the Measurement Results if the MA believes that they
are invalid
o filtering outlier Results o detail when Suppression started and ended
o calculating some statistic like average (beyond that defined by 5.4.1. Reporting of Subsriber's service parameters
the Measurement Task itself)
The measurement system may define what happens if a Collector The Subscriber's service parameters are information about his/her
unexpectedly does not hear from a MA, for example the Controller broadband contract, line rate and so on. Such information is likely
could send a fresh Report Schedule to the MA. to be needed to help analyse the Measurement Results, for example to
help decide whether the measured download speed is reasonable.
The LMAP WG will define a Report Protocol and its associated Data The information could be transferred directly from the Subscriber
Model that implements the Information Model and protocol model. This parameter database to the data analysis tools. It may also be
may be a simple instruction-response protocol. possible to transfer the information via the MA. How (and if) the MA
knows such information is likely to depend on the device type. The
MA could either include the information in a Measurement Report or
run a separate Data Transfer Task. All such considerations are out
of scope of LMAP.
5.5. Operation of LMAP over the underlying transport protocol 5.5. Operation of LMAP over the underlying transport protocol
The above sections have described LMAP's protocol model. The LMAP The above sections have described LMAP's protocol model. As part of
working group will also specify how it operates over an existing the design of the Control and Report Protocols, the LMAP working
protocol, to be selected, for example REST-style HTTP(S). It is also group will specify operation over an existing protocol, to be
possible that a different choice is made for the Control and Report selected, for example REST-style HTTP(S). It is also possible that a
Protocols, for example NETCONF-YANG and IPFIX respectively. It is different choice is made for the Control and Report Protocols, for
even possible that a different choice could be made for Suppression example NETCONF-YANG and IPFIX respectively.
and for other Instruction messages.
From an LMAP perspective, the Controller needs to know that the MA
has received the Instruction Message, or at least that it needs to be
re-sent as it may have failed to be delivered. Similarly the MA
needs to know about the delivery of Capabilities and Failure
information to the Controller and Reports to the Collector. How this
is done depends on the design of the Control and Report Protocols and
the underlying transport protocol.
For the Control Protocol, the underlying transport protocol could be: For the Control Protocol, the underlying transport protocol could be:
o a 'push' protocol (that is, from the Controller to the MA) o a 'push' protocol (that is, from the Controller to the MA)
o a multicast protocol (from the Controller to a group of MAs) o a multicast protocol (from the Controller to a group of MAs)
o a 'pull' protocol. The MA periodically checks with Controller if o a 'pull' protocol. The MA periodically checks with Controller if
the Instruction has changed and pulls a new Instruction if the Instruction has changed and pulls a new Instruction if
necessary. A pull protocol seems attractive for a MA behind a NAT necessary. A pull protocol seems attractive for a MA behind a NAT
skipping to change at page 23, line 20 skipping to change at page 23, line 44
are out of scope of definition by the LMAP WG: are out of scope of definition by the LMAP WG:
1. It does not define a coordination process between MAs. Whilst a 1. It does not define a coordination process between MAs. Whilst a
measurement system may define coordinated Measurement Schedules measurement system may define coordinated Measurement Schedules
across its various MAs, there is no direct coordination between across its various MAs, there is no direct coordination between
MAs. MAs.
2. It does not define interactions between the Collector and 2. It does not define interactions between the Collector and
Controller. It is quite likely that there will be such Controller. It is quite likely that there will be such
interactions, optionally intermediated by the data analysis interactions, optionally intermediated by the data analysis
tools. For example if there is an "interesting" Measurement tools. For example, if there is an "interesting" Measurement
Result then the measurement system may want to trigger extra Result then the measurement system may want to trigger extra
Measurement Tasks that explore the potential cause in more Measurement Tasks that explore the potential cause in more
detail. detail; or if the Collector unexpectedly does not hear from a MA,
then the measurement system may want to trigger the Controller to
send a fresh Instruction Message to the MA.
3. It does not define coordination between different measurement 3. It does not define coordination between different measurement
systems. For example, it does not define the interaction of a MA systems. For example, it does not define the interaction of a MA
in one measurement system with a Controller or Collector in a in one measurement system with a Controller or Collector in a
different measurement system. Whilst it is likely that the different measurement system. Whilst it is likely that the
Control and Report Protocols could be re-used or adapted for this Control and Report Protocols could be re-used or adapted for this
scenario, any form of coordination between different scenario, any form of coordination between different
organisations involves difficult commercial and technical issues organisations involves difficult commercial and technical issues
and so, given the novelty of large-scale measurement efforts, any and so, given the novelty of large-scale measurement efforts, any
form of inter-organisation coordination is outside the scope of form of inter-organisation coordination is outside the scope of
the LMAP WG. Note that a single MA is instructed by a single the LMAP WG. Note that a single MA is instructed by a single
Controller and is only in one measurement system. Controller and is only in one measurement system.
* An interesting scenario is where a home contains two * An interesting scenario is where a home contains two
independent MAs, for example one controlled by a regulator and independent MAs, for example one controlled by a regulator and
one controlled by an ISP. Then the Active Measurement Traffic one controlled by an ISP. Then the Active Measurement Traffic
of one MA is treated by the other MA just like any other user of one MA is treated by the other MA just like any other end-
traffic. user traffic.
4. It does not consider how to prevent a malicious party "gaming the 4. It does not consider how to prevent a malicious party "gaming the
system". For example, where a regulator is running a measurement system". For example, where a regulator is running a measurement
system in order to benchmark operators, a malicious operator system in order to benchmark operators, a malicious operator
could try to identify the broadband lines that the regulator was could try to identify the broadband lines that the regulator was
measuring and prioritise that traffic. It is assumed this is a measuring and prioritise that traffic. It is assumed this is a
policy issue and would be dealt with through a code of conduct policy issue and would be dealt with through a code of conduct
for instance. for instance.
5. It does not define how to analyse Measurement Results, including 5. It does not define how to analyse Measurement Results, including
how to interpret missing Results. how to interpret missing Results.
6. It does not specifically define a enduser-controlled measurement 6. It does not specifically define a end-user-controlled measurement
system, see sub-section 5.6.1. system, see sub-section 5.6.1.
5.6.1. Enduser-controlled measurement system 5.6.1. End-user-controlled measurement system
The WG concentrates on the cases where an ISP or a regulator runs the The WG concentrates on the cases where an ISP or a regulator runs the
measurement system. However, we expect that LMAP functionality will measurement system. However, we expect that LMAP functionality will
also be used in the context of an enduser-controlled measurement also be used in the context of an end-user-controlled measurement
system. There are at least two ways this could happen (they have system. There are at least two ways this could happen (they have
various pros and cons): various pros and cons):
1. an enduser could somehow request the ISP- (or regulator-) run 1. an end-user could somehow request the ISP- (or regulator-) run
measurement system to test his/her line. The ISP (or regulator) measurement system to test his/her line. The ISP (or regulator)
Controller would then send an Instruction to the MA in the usual Controller would then send an Instruction to the MA in the usual
LMAP way. Note that a user can't directly initiate a Measurement LMAP way. Note that a user can't directly initiate a Measurement
Task on an ISP- (or regulator-) controlled MA. Task on an ISP- (or regulator-) controlled MA.
2. an enduser could deploy their own measurement system, with their 2. an end-user could deploy their own measurement system, with their
own MA, Controller and Collector. For example, the user could own MA, Controller and Collector. For example, the user could
implement all three functions onto the same enduser-owned end implement all three functions onto the same end-user-owned end
device, perhaps by downloading the functions from the ISP or device, perhaps by downloading the functions from the ISP or
regulator. Then the LMAP Control and Report Protocols do not regulator. Then the LMAP Control and Report Protocols do not
need to be used, but using LMAP's Information Model would still need to be used, but using LMAP's Information Model would still
be beneficial. The Measurement Peer could be in the home gateway be beneficial. The Measurement Peer (or other MA involved in the
or outside the home network; in the latter case the Measurement Measurement Task) could be in the home gateway or outside the
Peer is highly likely to be run by a different organisation, home network; in the latter case the Measurement Peer is highly
which raises extra privacy considerations. likely to be run by a different organisation, which raises extra
privacy considerations.
In both cases there will be some way for the user to initiate the In both cases there will be some way for the end-user to initiate the
Measurement Task(s). The mechanism is out-of-scope of the LMAP WG, Measurement Task(s). The mechanism is out-of-scope of the LMAP WG,
but could include the user clicking a button on a GUI or sending a but could include the user clicking a button on a GUI or sending a
text message. Presumably the user will also be able to see the text message. Presumably the user will also be able to see the
Measurement Results, perhaps summarised on a webpage. It is Measurement Results, perhaps summarised on a webpage. It is
suggested that these interfaces conform to the LMAP guidance on the suggested that these interfaces conform to the LMAP guidance on
privacy in Section 8. privacy in Section 8.
6. Deployment considerations 6. Deployment considerations
6.1. Controller The Appendix has some examples of possible deployment arrangements of
Measurement Agents and Peers.
6.1. Controller and the measurement system
The Controller should understand both the MA's LMAP Capabilities (for The Controller should understand both the MA's LMAP Capabilities (for
instance what Measurement Methods it can perform) and about the MA's instance what Measurement Methods it can perform) and about the MA's
other capabilities like processing power and memory. This allows the other capabilities like processing power and memory. This allows the
Controller to make sure that the Measurement Schedule of Measurement Controller to make sure that the Measurement Schedule of Measurement
Tasks and the Reporting Schedule are sensible for each MA that it Tasks and the Reporting Schedule are sensible for each MA that it
Instructs. Instructs.
An Instruction is likely to include several Measurement Tasks. An Instruction is likely to include several Measurement Tasks.
Typically these run at different times, but it is also possible for Typically these run at different times, but it is also possible for
them to run at the same time, if the Controller is sure that one Task them to run at the same time. Some Tasks may be compatible, in that
will not affect the Results of another Task. they do not affect each other's Results, whilst with others great
care would need to be taken.
The Controller should ensure that the Active Measurement Tasks do not The Controller should ensure that the Active Measurement Tasks do not
have an adverse effect on the end user. Typically Tasks, especially have an adverse effect on the end user. Typically Tasks, especially
those that generate a substantial amount of traffic, will include a those that generate a substantial amount of traffic, will include a
pre-check that the user isn't already sending traffic (Section 5.3). pre-check that the user isn't already sending traffic (Section 5.3).
Another consideration is whether Active Measurement Traffic will Another consideration is whether Active Measurement Traffic will
impact a Subscriber's bill or traffic cap. impact a Subscriber's bill or traffic cap; if it will, then the
measurement system may need to compensate the Subscriber, for
instance.
The different elements of the Instruction can be updated The different elements of the Instruction can be updated
independently. For example, the Measurement Tasks could be independently. For example, the Measurement Tasks could be
configured with different Input Parameters whilst keeping the same configured with different Input Parameters whilst keeping the same
Measurement Schedule. In general this should not create any issues, Measurement Schedule. In general this should not create any issues,
since Measurement Methods should be defined so their fundamental since Measurement Methods should be defined so their fundamental
nature does not change for a new value of Input Parameter. There nature does not change for a new value of Input Parameter. There
could be a problem if, for example, a Measurement Task involving a could be a problem if, for example, a Measurement Task involving a
1kB file upload could be changed into a 1GB file upload. 1kB file upload could be changed into a 1GB file upload.
A measurement system may have multiple Controllers (but note the A measurement system may have multiple Controllers (but note the
overriding principle that a single MA is instructed by a single overriding principle that a single MA is instructed by a single
Controller at any point in time (Section 4.2)). For example, there Controller at any point in time (Section 4.2)). For example, there
could be different Controllers for different types of MA (home could be different Controllers for different types of MA (home
gateways, tablets) or locations (Ipswich, Edinburgh), for load gateways, tablets) or locations (Ipswich, Edinburgh), for load
balancing or to cope with failure of one Controller. One possibility balancing or to cope with failure of one Controller.
is that Bootstrapping involves an initial Controller, whose role is
simply to inform the MA how to contact its actual Controller. The measurement system also needs to consider carefully how to
interpret missing Results; for example, if the missing Results are
ignored and the lack of a Report is caused by its broadband being
broken, then the estimate of overall performance, averaged across all
MAs, would be too optimistic.
6.2. Measurement Agent 6.2. Measurement Agent
The Measurement Agent could take a number of forms: a dedicated The Measurement Agent could take a number of forms: a dedicated
probe, software on a PC, embedded into an appliance, or even embedded probe, software on a PC, embedded into an appliance, or even embedded
into a gateway. A single site (home, branch office etc.) that is into a gateway. A single site (home, branch office etc.) that is
participating in a measurement could make use of one or multiple participating in a measurement could make use of one or multiple
Measurement Agents in a single measurement. If the site is multi Measurement Agents or Measurement Peers in a single measurement.
homed there might be a Measurement Agent per interface.
The Measurement Agent could be deployed in a variety of locations. The Measurement Agent could be deployed in a variety of locations.
Not all deployment locations are available to every kind of Not all deployment locations are available to every kind of
Measurement Agent. There are also a variety of limitations and Measurement Agent. There are also a variety of limitations and
trade-offs depending on the final placement. The next sections trade-offs depending on the final placement. The next sections
outline some of the locations a Measurement Agent may be deployed. outline some of the locations a Measurement Agent may be deployed.
This is not an exhaustive list and combinations may also apply. This is not an exhaustive list and combinations may also apply.
If the Instruction includes several Measurement Tasks, these could be 6.2.1. Measurement Agent on a networked device
scheduled to run at different times or possibly at the same time -
some Tasks may be compatible, in that they do not affect each other's
Results, whilst with others great care would need to be taken.
The measurement system also needs to consider carefully how to A MA may be embedded on a device that is directly connected to the
interpret missing Results; for example, if the missing Results are network, such as a MA on a smartphone.
ignored and the lack of a Report is caused by its broadband being
broken, then the estimate of overall performance, averaged across all
MAs, would be too optimistic.
6.2.1. Measurement Agent embedded in site gateway 6.2.2. Measurement Agent embedded in site gateway
A Measurement Agent embedded with the site gateway, for example a A Measurement Agent embedded with the site gateway, for example a
home router or the edge router of a branch office in a managed home router or the edge router of a branch office in a managed
service environment, is one of better places the Measurement Agent service environment, is one of better places the Measurement Agent
could be deployed. All site-to-ISP traffic would traverse through could be deployed. All site-to-ISP traffic would traverse through
the gateway and passive measurements could easily be performed. the gateway and passive measurements could easily be performed.
Similarly, due to this user traffic visibility, an Active Similarly, due to this user traffic visibility, an Active Measurement
Measurements Task could be rescheduled so as not to compete with user Task could be rescheduled so as not to compete with user traffic.
traffic. Generally NAT and firewall services are built into the
gateway, allowing the Measurement Agent the option to offer its Generally NAT and firewall services are built into the gateway,
Controller facing management interface outside of the NAT/firewall. allowing the Measurement Agent the option to offer its Controller-
This placement of the management interface allows the Controller to facing management interface outside of the NAT/firewall. This
placement of the management interface allows the Controller to
unilaterally contact the Measurement Agent for instructions. unilaterally contact the Measurement Agent for instructions.
However, if the site gateway is owned and operated by the service However, if the site gateway is owned and operated by the service
provider, the Measurement Agent will generally not be directly provider, the Measurement Agent will generally not be directly
available for over the top providers, the regulator, end users or available for over the top providers, the regulator, end users or
enterprises. enterprises.
6.2.2. Measurement Agent embedded behind site NAT /Firewall 6.2.3. Measurement Agent embedded behind site NAT /Firewall
The Measurement Agent could also be embedded behind a NAT, a The Measurement Agent could also be embedded behind a NAT, a
firewall, or both. In this case the Controller may not be able to firewall, or both. In this case the Controller may not be able to
unilaterally contact the Measurement Agent unless either static port unilaterally contact the Measurement Agent unless either static port
forwarding configuration or firewall pin holing is configured, and forwarding configuration or firewall pin holing is configured. For
might not always be possible. It would require user intervention or the former, protocols such as PCP [RFC6887], TR-069 [TR-069]or UPnP
pre-provisioning by the operator via a mechanisms such as TR-069. [UPnP]could be used. For the latter, the Measurement Agent could
The Measurement Agent may originate a session towards the Controller send keepalives towards the Controller to prop open the firewall (and
and maintain the session for bidirectional communications. This perhaps use these also as a network reachability test).
would alleviate the need to have user intervention on the gateway,
but would reduce the overall saleability of the Controller as it
would have to maintain a higher number of active sessions. That
said, sending keepalives to prop open the firewall could serve a dual
purpose in testing network reachability for the Measurement Agent.
An alternative would be to use a protocol such as UPnP or PCP
[RFC6887] to control the NAT/firewall if the gateway supports this
kind of control.
6.2.3. Measurement Agent in a multi-homed site 6.2.4. Multi-homed Measurement Agent
A broadband site may be multi-homed. For example, the site may be If the device with the Measurement Agent is single homed then there
connected to multiple broadband ISPs, perhaps for redundancy or load- is no confusion about what interface to measure. Similarly, if the
sharing, or have both wired and wireless broadband connectivity. It MA is at the gateway and the gateway only has a single WAN-side and a
may also be helpful to think of dual stack IPv4 and IPv6 broadband single LAN-side interface, there is little confusion - for an Active
devices as multi-homed. In these cases, there needs to be clarity on Measurement Task, the location of the other MA or Measurement Peer
which network connectivity option is being measured. Sometimes this determines whether the WAN or LAN is measured.
is easily resolved by the location of the MA itself. For example, if
the MA is built into the gateway (and the gateway only has a single However, the device with the Measurement Agent may be multi-homed.
WAN side interface), there is little confusion or choice. However, For example, a home or campus may be connected to multiple broadband
for multi-homed gateways or devices behind the gateway(s) of multi- ISPs, such as a wired and wireless broadband provider, perhaps for
homed sites it would be preferable to explicitly select the network redundancy or load- sharing. It may also be helpful to think of dual
to measure ([RFC5533]) but the network measured should be included in stack IPv4 and IPv6 broadband devices as multi-homed. More
the Measurement Result. Section 3.2 of [I-D.ietf-homenet-arch] generally, Section 3.2 of [I-D.ietf-homenet-arch] describes dual-
describes dual-stack and multi-homing topologies that might be stack and multi-homing topologies that might be encountered in a home
encountered in a home network (which is generally a broadband network, [RFC6419] provides the current practices of multi-interfaces
connected site). The Multiple Interfaces (mif) working group covers hosts, and the Multiple Interfaces (mif) working group covers cases
cases where hosts are either directly attached to multiple networks where hosts are either directly attached to multiple networks
(physical or virtual) or indirectly (multiple default routers, etc.). (physical or virtual) or indirectly (multiple default routers, etc.).
[RFC6419] provides the current practices of multi-interfaces hosts In these cases, there needs to be clarity on which network
today. As one aim is for a MA is to measure the end user's quality connectivity option is being measured.
of experience, it is important to understand the current practices.
One possibility is to have a Measurement Agent per interface. Then
the Controller's choice of MA determines which interface is measured.
However, if a MA can measure any of the interfaces, then the
Controller defines in the Instruction which interface the MA should
use for a Measurement Task; if the choice of interface is not defined
then the MA uses the default one. Explicit definition is preferred
if the measurement system wants to measure the performance of a
particular network, whereas using the default is better if the
measurement system wants to include the impact of the MA's interface
selection algorithm. In any case, the Measurement Result should
include the network that was measured.
6.3. Measurement Peer 6.3. Measurement Peer
A Measurement Peer participates in Active Measurement Tasks. It may A Measurement Peer participates in Active Measurement Tasks. It may
have specific functionality to enable it to participate in a have specific functionality to enable it to participate in a
particular Measurement Method. On the other hand, other Measurement particular Measurement Method. On the other hand, other Measurement
Methods may require no special functionality, for example if the Methods may require no special functionality, for example if the
Measurement Agent sends a ping to example.com then the server at Measurement Agent sends a ping to example.com then the server at
example.com plays the role of a Measurement Peer. example.com plays the role of a Measurement Peer.
A device may participate in some Measurement Tasks as a Measurement A device may participate in some Measurement Tasks as a Measurement
Agent and in others as a Measurement Peer. Agent and in others as a Measurement Peer.
Measurement schedules should account for limited resources in a
Measurement Peer when instructing a MA to execute measurements with a
Measurement Peer. In some measurement protocols, such as [RFC4656]
and [RFC5357], the Measurement Peer can reject a measurement session
or refuse a control connection prior to setting-up a measurement
session and so protect itself from resource exhaustion. This is a
valuable capability because the MP may be used by more than one
organisation.
7. Security considerations 7. Security considerations
The security of the LMAP framework should protect the interests of The security of the LMAP framework should protect the interests of
the measurement operator(s), the network user(s) and other actors who the measurement operator(s), the network user(s) and other actors who
could be impacted by a compromised measurement deployment. The could be impacted by a compromised measurement deployment. The
measurement system must secure the various components of the system measurement system must secure the various components of the system
from unauthorised access or corruption. from unauthorised access or corruption. Much of the general advice
contained in section 6 of [RFC4656] is applicable here.
We assume that each Measurement Agent (MA) will receive its We assume that each Measurement Agent (MA) will receive its
Instructions from a single organisation, which operates the Instructions from a single organisation, which operates the
Controller. These Instructions must be authenticated (to ensure that Controller. These Instructions must be authenticated (to ensure that
they come from the trusted Controller), checked for integrity (to they come from the trusted Controller), checked for integrity (to
ensure no-one has tampered with them) and not vulnerable to replay ensure no-one has tampered with them) and not vulnerable to replay
attacks. If a malicious party can gain control of the MA they can attacks. If a malicious party can gain control of the MA they can
use it to launch DoS attacks at targets, reduce the end user's use it to launch DoS attacks at targets, reduce the end user's
quality of experience and corrupt the Measurement Results that are quality of experience and corrupt the Measurement Results that are
reported to the Collector. By altering the Measurement Tasks and/or reported to the Collector. By altering the Measurement Tasks and/or
the address that Results are reported to, they can also compromise the address that Results are reported to, they can also compromise
the confidentiality of the network user and the MA environment (such the confidentiality of the network user and the MA environment (such
as information about the location of devices or their traffic). as information about the location of devices or their traffic).
The process to upgrade the firmware in an MA is out-of-scope for this
phase of LMAP development, similar to the protocol to bootstrap the
MAs (as specified in the charter). However, systems which provide
remote upgrade must secure authorised access and integrity of the
process.
Reporting by the MA must also be secured to maintain confidentiality. Reporting by the MA must also be secured to maintain confidentiality.
The results must be encrypted such that only the authorised Collector The results must be encrypted such that only the authorised Collector
can decrypt the results to prevent the leakage of confidential or can decrypt the results to prevent the leakage of confidential or
private information. In addition it must be authenticated that the private information. In addition it must be authenticated that the
results have come from the expected MA and that they have not been results have come from the expected MA and that they have not been
tampered with. It must not be possible to fool a MA into injecting tampered with. It must not be possible to fool a MA into injecting
falsified data into the measurement platform or to corrupt the falsified data into the measurement platform or to corrupt the
results of a real MA. The results must also be held and processed results of a real MA. The results must also be held and processed
securely after collection and analysis. securely after collection and analysis. See section 8.5.2 below for
additional considerations on stored data compromise, and section 8.6
on potential mitigations for compromise.
Since Collectors will be contacted repeatedly by MAs using the
Collection Protocol to convey their recent results, a successful
attack to exhaust the communication resources would prevent a
critical operation: reporting. Therefore, all LMAP Collectors should
implement technical mechanisms to:
o limit the number of reporting connections from a single MA
(simultaneous, and connections per unit time).
o limit the transmission rate from a single MA.
o limit the memory/storage consumed by a single MA's reports.
o efficiently reject reporting connections from unknown sources.
o separate resources if multiple authentication strengths are used,
where the resources should be separated according to each class of
strength.
o limit iteration counters to generate keys with both a lower and
upper limit, to prevent an attacking system from requesting the
maximum and causing the Controller to stall on the process (see
section 6 of [RFC5357]).
Many of the above considerations are applicable to Controllers using
a "push" model, where the MA must contact the Controller because NAT
or other network aspect prevents Controllers from contacting MAs
directly.
Availability should also be considered. While the loss of some MAs Availability should also be considered. While the loss of some MAs
may not be considered critical, the unavailability of the Collector may not be considered critical, the unavailability of the Collector
could mean that valuable business data or data critical to a could mean that valuable business data or data critical to a
regulatory process is lost. Similarly, the unavailability of a regulatory process is lost. Similarly, the unavailability of a
Controller could mean that the MAs do not operate a correct Controller could mean that the MAs do not operate a correct
Measurement Schedule. Measurement Schedule.
A malicious party could "game the system". For example, where a A malicious party could "game the system". For example, where a
regulator is running a measurement system in order to benchmark regulator is running a measurement system in order to benchmark
skipping to change at page 31, line 12 skipping to change at page 32, line 44
system (however briefly this storage may be). We note that some system (however briefly this storage may be). We note that some
authorities make a distinction on time of storage, and information authorities make a distinction on time of storage, and information
that is kept only temporarily to perform a communications function is that is kept only temporarily to perform a communications function is
not subject to regulation (for example, active queue management, deep not subject to regulation (for example, active queue management, deep
packet inspection). Passive Measurement Tasks could reveal all the packet inspection). Passive Measurement Tasks could reveal all the
websites a Subscriber visits and the applications and/or services websites a Subscriber visits and the applications and/or services
they use. they use.
Active Measurement Tasks are conducted on traffic which is created Active Measurement Tasks are conducted on traffic which is created
specifically for the purpose. Even if a user host generates Active specifically for the purpose. Even if a user host generates Active
Measurement Traffic, there is significantly limited sensitive Measurement Traffic, there is limited sensitive information about the
information about the Subscriber present and stored in the Subscriber present and stored in the measurement system compared to
measurement system compared to the passive case, as follows: the passive case, as follows:
o IP address in use (and possibly sub-IP addresses and names) o IP address in use (and possibly sub-IP addresses and names)
o Status as a study volunteer and Schedule of Active Measurement o Status as a study volunteer and Schedule of Active Measurement
Tasks Tasks
On the other hand, for a service provider the sensitive information On the other hand, for a service provider the sensitive information
like Measurement Results is the same for Passive and Active like Measurement Results is the same for Passive and Active
Measurement Tasks. Measurement Tasks.
skipping to change at page 31, line 36 skipping to change at page 33, line 20
Tasks potentially expose the description of Internet access service Tasks potentially expose the description of Internet access service
and specific service parameters, such as subscribed rate and type of and specific service parameters, such as subscribed rate and type of
access. access.
8.4. Privacy analysis of the Communications Models 8.4. Privacy analysis of the Communications Models
This section examines each of the protocol exchanges described at a This section examines each of the protocol exchanges described at a
high level in Section 5 and some example Measurement Tasks, and high level in Section 5 and some example Measurement Tasks, and
identifies specific sensitive information which must be secured identifies specific sensitive information which must be secured
during communication for each case. With the protocol-related during communication for each case. With the protocol-related
sensitive information identified, we have can better consider the sensitive information identified, we can better consider the threats
threats described in the following section. described in the following section.
From the privacy perspective, all entities participating in LMAP From the privacy perspective, all entities participating in LMAP
protocols can be considered "observers" according to the definition protocols can be considered "observers" according to the definition
in [RFC6973]. Their stored information potentially poses a threat to in [RFC6973]. Their stored information potentially poses a threat to
privacy, especially if one or more of these functional entities has privacy, especially if one or more of these functional entities has
been compromised. Likewise, all devices on the paths used for been compromised. Likewise, all devices on the paths used for
control, reporting, and measurement are also observers. control, reporting, and measurement are also observers.
8.4.1. MA Bootstrapping 8.4.1. MA Bootstrapping
skipping to change at page 36, line 47 skipping to change at page 38, line 47
communications between the local storage of the Collector and the communications between the local storage of the Collector and the
repository is beyond the scope of the LMAP work at this time, though repository is beyond the scope of the LMAP work at this time, though
this communications channel will certainly need protection as well as this communications channel will certainly need protection as well as
the mass storage itself. the mass storage itself.
The LMAP Controller may have direct access to storage of Subscriber The LMAP Controller may have direct access to storage of Subscriber
information (location, billing, service parameters, etc.) and other information (location, billing, service parameters, etc.) and other
information which the controlling organisation considers private, and information which the controlling organisation considers private, and
again needs protection. again needs protection.
Note that there is tension between the desire to store all raw
results in the LMAP Collector (for reproduceability and custom
analysis), and the need to protect the privacy of measurement
participants. Many of the compromise mitigations described in
section 8.6 below are most efficient when deployed at the MA,
therefore minimizing the risks with stored results.
8.5.3. Correlation and Identification 8.5.3. Correlation and Identification
Sections 5.2.1 and 5.2.2 of [RFC6973] describes Correlation as Sections 5.2.1 and 5.2.2 of [RFC6973] describes Correlation as
combining various pieces of information to obtain desired combining various pieces of information to obtain desired
characteristics of an individual, and Identification as using this characteristics of an individual, and Identification as using this
process to infer identity. process to infer identity.
The main risk is that the LMAP system could unwittingly provide a key The main risk is that the LMAP system could unwittingly provide a key
piece of the correlation chain, starting with an unknown Subscriber's piece of the correlation chain, starting with an unknown Subscriber's
IP address and another piece of information. For example, a IP address and another piece of information. For example, a
skipping to change at page 40, line 29 skipping to change at page 42, line 34
to be secure from unauthorised access. This is the hand-off between to be secure from unauthorised access. This is the hand-off between
privacy and security considerations (Section 7). The Data Controller privacy and security considerations (Section 7). The Data Controller
has the (legal) responsibility to maintain data protections described has the (legal) responsibility to maintain data protections described
in the Subscriber's agreement and agreements with other in the Subscriber's agreement and agreements with other
organisations. organisations.
9. IANA Considerations 9. IANA Considerations
There are no IANA considerations in this memo. There are no IANA considerations in this memo.
10. Acknowledgments 10. Appendix: Deployment examples
In this section we describe some deployment scenarios that are
feasible within the LMAP framework defined in this document.
The LMAP framework defines two types of components involved in the
actual measurement task, namely the Measurement Agent (MA) and the
Measurement Peer (MP). The fundamental difference conveyed in the
definition of these terms is that the MA has a interface with the
Controller/Collector while the MP does not. The MP is broadly
defined as a function that assists the MA in the Measurement Task but
has no interface with the Controller/Collector. There are many
elements in the network that can fall into this broad definition of
MP. We believe that the MP terminology is useful to allow us to
refer an element of the network that plays a role that is
conceptually important to understand and describe the measurement
task being performed. We next illustrate these concepts by
describing several deployment scenarios.
A very simple example of a Measurement Peer is a web server that the
MA is downloading a web page from (such as www.example.com) in order
to perform a speed test. The web server is an MP and from its
perspective, the MA is just another customer; the MP doesn't have a
specific function for assisting measurements. This is described in
the figure A1.
^
+----------------+ Web Traffic +----------------+ IPPM
| Web Client |<------------>| MP: Web Server | Scope
| | +----------------+ |
...|................|....................................V...
| LMAP interface | ^
+----------------+ |
^ | |
Instruction | | Report |
| +-----------------+ |
| | |
| v LMAP
+------------+ +------------+ Scope
| Controller | | Collector | |
+------------+ +------------+ V
Figure A1: Schematic of LMAP-based measurement system,
with Web server as Measurement Peer
Another case that is slightly different than this would be the one of
a ping responder. This is also an MP, with a helper function, the
ping server, which is specially deployed to assist the MAs that
perform pings. It only has the data plane interface. This example
is described in Section 2.
A third related example would be the case of a traceroute like
measurement. In this case, for each packet sent, the router where
the TTL expires is performing the MP function. So for a given
Measurement Task, there is one MA involved and several MPs, one per
hop.
In figure A2 we depict the case of an OWAMP responder acting as an
MP. In this case, the helper function in addition reports results
back to the MA. So it has both a data plane and control interface
with the MA.
+----------------+ OWAMP +----------------+ ^
| OWAMP |<--control--->| MP: | |
| control-client |>test-traffic>| OWAMP server & | IPPM
| fetch-client & |<----fetch----| session-rec'ver| Scope
| session-sender | | | |
| | +----------------+ |
...|................|....................................v...
| LMAP interface | ^
+----------------+ |
^ | |
Instruction | | Report |
| +-----------------+ |
| | |
| v LMAP
+------------+ +------------+ Scope
| Controller | | Collector | |
+------------+ +------------+ v
IPPM
Figure A2: Schematic of LMAP-based measurement system,
with OWAMP server as Measurement Peer
However, it is also possible to use two Measurement Agents when
performing one way Measurement Tasks, as described in figure A3
below. In this case, MA1 generates the traffic and MA2 receives the
traffic and send the reports to the Collector. Note that both MAs
are instructed by the Controller. MA1 receives an Instruction to
send the traffic and MA2 receives an Instruction to measured the
received traffic and send Reports to the Collector.
+----------------+ +----------------+ ^
| MA1 | | MA2 | IPPM
| iperf -u sender|-UDP traffic->| iperf -u recvr | Scope
| | | | v
...|................|..............|................|....v...
| LMAP interface | | LMAP interface | ^
+----------------+ +----------------+ |
^ ^ | |
Instruction | Instruction{Report} | | Report |
{task, | +-------------------+ | |
schedule} | | | |
| | v LMAP
+------------+ +------------+ Scope
| Controller | | Collector | |
+------------+ +------------+ v
IPPM
Figure A3: Schematic of LMAP-based measurement system,
with two Measurement Agents cooperating to measure UDP traffic
Next, we consider Passive Measurement Tasks. Traffic generated in
one point in the network flowing towards a given destination and the
traffic is passively observed in some point along the path. One way
to implement this is that the endpoints generating and receiving the
traffic are not instructed by the Controller; hence they are MPs.
The MA is located along the path with a passive monitor function that
measures the traffic. The MA is instructed by the Controller to
monitor that particular traffic and to send the Report to the
Collector. It is depicted in figure A4 below.
+-----+ +----------------+ +------+ ^
| MP | | Passive Monitor| | MP | IPPM
| |<--|----------------|---traffic--->| | Scope
+-----+ | | +------+ |
.......|................|.........................v...........
| LMAP interface | ^
+----------------+ |
^ | |
Instruction | | Report |
| +-----------------+ |
| | |
| v LMAP
+------------+ +------------+ Scope
| Controller | | Collector | |
+------------+ +------------+ v
Figure A4: Schematic of LMAP-based measurement system,
with a Measurement Agent passively monitoring traffic
Finally, we should consider the case of a router or a switch along
the measurement path. This certainly performs an important role in
the measurement - if packets are not forwarded, the measurement task
will not work. Whilst it doesn't has an interface with the
Controller or Collector, and so fits into the definition of MP,
usually it is not particularly useful to highlight it as a MP.
11. Acknowledgments
This document is a merger of three individual drafts: draft-eardley- This document is a merger of three individual drafts: draft-eardley-
lmap-terminology-02, draft-akhter-lmap-framework-00, and draft- lmap-terminology-02, draft-akhter-lmap-framework-00, and draft-
eardley-lmap-framework-02. eardley-lmap-framework-02.
Thanks to Juergen Schoenwaelder for his detailed review of the Thanks to Juergen Schoenwaelder for his detailed review of the
terminology. Thanks to Charles Cook for a very detailed review of terminology. Thanks to Charles Cook for a very detailed review of
-02. -02.
Thanks to numerous people for much discussion, directly and on the Thanks to numerous people for much discussion, directly and on the
skipping to change at page 41, line 5 skipping to change at page 47, line 7
Guangqing Deng, Jason Weil, Jean-Francois Tremblay, Jerome Benoit, Guangqing Deng, Jason Weil, Jean-Francois Tremblay, Jerome Benoit,
Joachim Fabini, Juergen Schoenwaelder, Jukka Manner, Ken Ko, Michael Joachim Fabini, Juergen Schoenwaelder, Jukka Manner, Ken Ko, Michael
Bugenhagen, Rolf Winter, Sam Crawford, Sharam Hakimi, Steve Miller, Bugenhagen, Rolf Winter, Sam Crawford, Sharam Hakimi, Steve Miller,
Ted Lemon, Timothy Carey, Vaibhav Bajpai, William Lupton. Ted Lemon, Timothy Carey, Vaibhav Bajpai, William Lupton.
Philip Eardley, Trevor Burbridge and Marcelo Bagnulo work in part on Philip Eardley, Trevor Burbridge and Marcelo Bagnulo work in part on
the Leone research project, which receives funding from the European the Leone research project, which receives funding from the European
Union Seventh Framework Programme [FP7/2007-2013] under grant Union Seventh Framework Programme [FP7/2007-2013] under grant
agreement number 317647. agreement number 317647.
11. History 12. History
First WG version, copy of draft-folks-lmap-framework-00. First WG version, copy of draft-folks-lmap-framework-00.
11.1. From -00 to -01 12.1. From -00 to -01
o new sub-section of possible use of Group-IDs for privacy o new sub-section of possible use of Group-IDs for privacy
o tweak to definition of Control protocol o tweak to definition of Control protocol
o fix typo in figure in S5.4 o fix typo in figure in S5.4
11.2. From -01 to -02 12.2. From -01 to -02
o change to INFORMATIONAL track (previous version had typo'd o change to INFORMATIONAL track (previous version had typo'd
Standards track) Standards track)
o new definitions for Capabilities Information and Failure o new definitions for Capabilities Information and Failure
Information Information
o clarify that diagrams show LMAP-level information flows. o clarify that diagrams show LMAP-level information flows.
Underlying protocol could do other interactions, eg to get through Underlying protocol could do other interactions, eg to get through
NAT or for Collector to pull a Report NAT or for Collector to pull a Report
skipping to change at page 42, line 25 skipping to change at page 48, line 31
o add some extra words about the potential impact of Measurement o add some extra words about the potential impact of Measurement
Tasks Tasks
o clarified various aspects of the privacy section o clarified various aspects of the privacy section
o updated references o updated references
o minor tweaks o minor tweaks
11.3. From -02 to -03 12.3. From -02 to -03
o alignment with the Information Model o alignment with the Information Model
[I-D.burbridge-lmap-information-model] as this is agreed as a WG [I-D.burbridge-lmap-information-model] as this is agreed as a WG
document document
o One-off and periodic Measurement Schedules are kept separate, so o One-off and periodic Measurement Schedules are kept separate, so
that they can be updated independently that they can be updated independently
o Measurement Suppression in a separate sub-section. Can now o Measurement Suppression in a separate sub-section. Can now
optionally include particular Measurement Tasks &/or Schedules to optionally include particular Measurement Tasks &/or Schedules to
suppress, and start/stop time suppress, and start/stop time
o for clarity, concept of Channel split into Control, Report and MA- o for clarity, concept of Channel split into Control, Report and MA-
to-Controller Channels to-Controller Channels
o numerous editorial changes, mainly arising from a very detailed o numerous editorial changes, mainly arising from a very detailed
review by Charles Cook review by Charles Cook
o o
12. Informative References 12.4. From -03 to -04
o updates following the WG Last Call, with the proposed consensus on
the various issues as detailed in http://tools.ietf.org/agenda/89/
slides/slides-89-lmap-2.pdf. In particular:
o tweaked definitions, especially of Measurement Agent and
Measurement Peer
o Instruction - left to each implementation & deployment of LMAP to
decide on the granularity at which an Instruction Message works
o words added about overlapping Measurement Tasks (measurement
system can handle any way they choose; Report should mention if
the Task overlapped with another)
o Suppression: no defined impact on Passive Measurement Task; extra
option to suppress on-going Active Measurement Tasks; suppression
doesn't go to Measurement Peer, since they don't understand
Instructions
o new concept of Data Transfer Task (and therefore adjustment of the
Channel concept)
o enhancement of Results with Subscriber's service parameters -
could be useful, don't define how but can be included in Report to
various other sections
o various other smaller improvements, arising from the WGLC
o Appendix added with examples of Measurement Agents and Peers in
various deployment scenarios. To help clarify what these terms
mean.
o
13. Informative References
[Bur10] Burkhart, M., Schatzmann, D., Trammell, B., and E. Boschi, [Bur10] Burkhart, M., Schatzmann, D., Trammell, B., and E. Boschi,
"The Role of Network Trace anonymisation Under Attack", "The Role of Network Trace anonymisation Under Attack",
January 2010. January 2010.
[Q1741] Q.1741.7, , "IMT-2000 references to Release 9 of GSM- [Q1741] Q.1741.7, , "IMT-2000 references to Release 9 of GSM-
evolved UMTS core network", evolved UMTS core network",
http://www.itu.int/rec/T-REC-Q.1741.7/en, November 2011. http://www.itu.int/rec/T-REC-Q.1741.7/en, November 2011.
[TR-069] TR-069, , "CPE WAN Management Protocol",
http://www.broadband-forum.org/technical/trlist.php,
November 2013.
[UPnP] ISO/IEC 29341-x, , "UPnP Device Architecture and UPnP
Device Control Protocols specifications",
http://upnp.org/sdcps-and-certification/standards/, 2011.
[RFC1035] Mockapetris, P., "Domain names - implementation and [RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987. specification", STD 13, RFC 1035, November 1987.
[RFC4101] Rescorla, E. and IAB, "Writing Protocol Models", RFC 4101, [RFC4101] Rescorla, E. and IAB, "Writing Protocol Models", RFC 4101,
June 2005. June 2005.
[RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally
Unique IDentifier (UUID) URN Namespace", RFC 4122, July Unique IDentifier (UUID) URN Namespace", RFC 4122, July
2005. 2005.
[RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J. [RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)", Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
RFC 5357, October 2008. RFC 5357, October 2008.
[I-D.ietf-lmap-use-cases] [I-D.ietf-lmap-use-cases]
Linsner, M., Eardley, P., Burbridge, T., and F. Sorensen, Linsner, M., Eardley, P., Burbridge, T., and F. Sorensen,
"Large-Scale Broadband Measurement Use Cases", draft-ietf- "Large-Scale Broadband Measurement Use Cases", draft-ietf-
lmap-use-cases-01 (work in progress), December 2013. lmap-use-cases-02 (work in progress), January 2014.
[I-D.bagnulo-ippm-new-registry-independent] [I-D.manyfolks-ippm-metric-registry]
Bagnulo, M., Burbridge, T., Crawford, S., Eardley, P., and Bagnulo, M., Claise, B., Eardley, P., and A. Morton,
A. Morton, "A registry for commonly used metrics. "Registry for Performance Metrics", draft-manyfolks-ippm-
Independent registries", draft-bagnulo-ippm-new-registry- metric-registry-00 (work in progress), February 2014.
independent-01 (work in progress), July 2013.
[I-D.ietf-homenet-arch] [I-D.ietf-homenet-arch]
Chown, T., Arkko, J., Brandt, A., Troan, O., and J. Weil, Chown, T., Arkko, J., Brandt, A., Troan, O., and J. Weil,
"IPv6 Home Networking Architecture Principles", draft- "IPv6 Home Networking Architecture Principles", draft-
ietf-homenet-arch-11 (work in progress), October 2013. ietf-homenet-arch-13 (work in progress), March 2014.
[RFC6419] Wasserman, M. and P. Seite, "Current Practices for [RFC6419] Wasserman, M. and P. Seite, "Current Practices for
Multiple-Interface Hosts", RFC 6419, November 2011. Multiple-Interface Hosts", RFC 6419, November 2011.
[RFC6887] Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P. [RFC6887] Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P.
Selkirk, "Port Control Protocol (PCP)", RFC 6887, April Selkirk, "Port Control Protocol (PCP)", RFC 6887, April
2013. 2013.
[RFC5533] Nordmark, E. and M. Bagnulo, "Shim6: Level 3 Multihoming
Shim Protocol for IPv6", RFC 5533, June 2009.
[I-D.burbridge-lmap-information-model] [I-D.burbridge-lmap-information-model]
Burbridge, T., Eardley, P., Bagnulo, M., and J. Burbridge, T., Eardley, P., Bagnulo, M., and J.
Schoenwaelder, "Information Model for Large-Scale Schoenwaelder, "Information Model for Large-Scale
Measurement Platforms (LMAP)", draft-burbridge-lmap- Measurement Platforms (LMAP)", draft-burbridge-lmap-
information-model-01 (work in progress), October 2013. information-model-01 (work in progress), October 2013.
[RFC6235] Boschi, E. and B. Trammell, "IP Flow Anonymization [RFC6235] Boschi, E. and B. Trammell, "IP Flow Anonymization
Support", RFC 6235, May 2011. Support", RFC 6235, May 2011.
[RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J., [RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
Morris, J., Hansen, M., and R. Smith, "Privacy Morris, J., Hansen, M., and R. Smith, "Privacy
Considerations for Internet Protocols", RFC 6973, July Considerations for Internet Protocols", RFC 6973, July
2013. 2013.
[I-D.ietf-ippm-lmap-path] [I-D.ietf-ippm-lmap-path]
Bagnulo, M., Burbridge, T., Crawford, S., Eardley, P., and Bagnulo, M., Burbridge, T., Crawford, S., Eardley, P., and
A. Morton, "A Reference Path and Measurement Points for A. Morton, "A Reference Path and Measurement Points for
LMAP", draft-ietf-ippm-lmap-path-01 (work in progress), LMAP", draft-ietf-ippm-lmap-path-02 (work in progress),
September 2013. February 2014.
[RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M.
Zekauskas, "A One-way Active Measurement Protocol
(OWAMP)", RFC 4656, September 2006.
[RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
RFC 5357, October 2008.
[RFC3444] Pras, A. and J. Schoenwaelder, "On the Difference between
Information Models and Data Models", RFC 3444, January
2003.
Authors' Addresses Authors' Addresses
Philip Eardley Philip Eardley
British Telecom BT
Adastral Park, Martlesham Heath Adastral Park, Martlesham Heath
Ipswich Ipswich
ENGLAND ENGLAND
Email: philip.eardley@bt.com Email: philip.eardley@bt.com
Al Morton Al Morton
AT&T Labs AT&T Labs
200 Laurel Avenue South 200 Laurel Avenue South
Middletown, NJ Middletown, NJ
USA USA
Email: acmorton@att.com Email: acmorton@att.com
Marcelo Bagnulo Marcelo Bagnulo
Universidad Carlos III de Madrid Universidad Carlos III de Madrid
Av. Universidad 30 Av. Universidad 30
Leganes, Madrid 28911 Leganes, Madrid 28911
SPAIN SPAIN
Phone: 34 91 6249500 Phone: 34 91 6249500
Email: marcelo@it.uc3m.es Email: marcelo@it.uc3m.es
URI: http://www.it.uc3m.es URI: http://www.it.uc3m.es
skipping to change at page 45, line 15 skipping to change at page 52, line 23
Universidad Carlos III de Madrid Universidad Carlos III de Madrid
Av. Universidad 30 Av. Universidad 30
Leganes, Madrid 28911 Leganes, Madrid 28911
SPAIN SPAIN
Phone: 34 91 6249500 Phone: 34 91 6249500
Email: marcelo@it.uc3m.es Email: marcelo@it.uc3m.es
URI: http://www.it.uc3m.es URI: http://www.it.uc3m.es
Trevor Burbridge Trevor Burbridge
British Telecom BT
Adastral Park, Martlesham Heath Adastral Park, Martlesham Heath
Ipswich Ipswich
ENGLAND ENGLAND
Email: trevor.burbridge@bt.com Email: trevor.burbridge@bt.com
Paul Aitken Paul Aitken
Cisco Systems, Inc. Cisco Systems, Inc.
96 Commercial Street 96 Commercial Street
Edinburgh, Scotland EH6 6LX Edinburgh, Scotland EH6 6LX
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