A Framework for Large-Scale Measurement of Broadband Performance (LMAP)
draft-ietf-lmap-framework-14

Network Working Group                                         P. Eardley
Internet-Draft                                                        BT
Intended status: Informational                                 A. Morton
Expires: July 25, 2014                                         AT&T Labs
                                                              M. Bagnulo
                                                                    UC3M
                                                            T. Burbridge
                                                                      BT
                                                               P. Aitken
                                                               A. Akhter
                                                           Cisco Systems
                                                        January 21, 2014


        A framework for large-scale measurement platforms (LMAP)
                      draft-ietf-lmap-framework-03

Abstract

   Measuring broadband service on a large scale requires a description
   of the logical architecture and standardisation of the key protocols
   that coordinate interactions between the components.  The document
   presents an overall framework for large-scale measurements.  It also
   defines terminology for LMAP (large-scale measurement platforms).

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on July 25, 2014.

Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.





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   This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Outline of an LMAP-based measurement system . . . . . . . . .   5
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   8
   4.  Constraints . . . . . . . . . . . . . . . . . . . . . . . . .  11
     4.1.  Measurement system is under the direction of a single
           organisation  . . . . . . . . . . . . . . . . . . . . . .  11
     4.2.  Each MA may only have a single Controller at any point in
           time  . . . . . . . . . . . . . . . . . . . . . . . . . .  12
   5.  LMAP Protocol Model . . . . . . . . . . . . . . . . . . . . .  12
     5.1.  Bootstrapping process . . . . . . . . . . . . . . . . . .  13
     5.2.  Control Protocol  . . . . . . . . . . . . . . . . . . . .  15
       5.2.1.  Measurement Suppression . . . . . . . . . . . . . . .  18
     5.3.  Starting and stopping Measurement Tasks . . . . . . . . .  19
     5.4.  Report Protocol . . . . . . . . . . . . . . . . . . . . .  20
     5.5.  Operation of LMAP over the underlying transport protocol   22
     5.6.  Items beyond the scope of the LMAP Protocol Model . . . .  23
       5.6.1.  Enduser-controlled measurement system . . . . . . . .  24
   6.  Deployment considerations . . . . . . . . . . . . . . . . . .  24
     6.1.  Controller  . . . . . . . . . . . . . . . . . . . . . . .  24
     6.2.  Measurement Agent . . . . . . . . . . . . . . . . . . . .  25
       6.2.1.  Measurement Agent embedded in site gateway  . . . . .  26
       6.2.2.  Measurement Agent embedded behind site NAT /Firewall   26
       6.2.3.  Measurement Agent in a multi-homed site . . . . . . .  27
     6.3.  Measurement Peer  . . . . . . . . . . . . . . . . . . . .  27
   7.  Security considerations . . . . . . . . . . . . . . . . . . .  27
   8.  Privacy Considerations for LMAP . . . . . . . . . . . . . . .  28
     8.1.  Categories of Entities with Information of Interest . . .  29
     8.2.  Examples of Sensitive Information . . . . . . . . . . . .  29
     8.3.  Key Distinction Between Active and Passive Measurement
           Tasks . . . . . . . . . . . . . . . . . . . . . . . . . .  30
     8.4.  Privacy analysis of the Communications Models . . . . . .  31
       8.4.1.  MA Bootstrapping  . . . . . . . . . . . . . . . . . .  31
       8.4.2.  Controller <-> Measurement Agent  . . . . . . . . . .  32
       8.4.3.  Collector <-> Measurement Agent . . . . . . . . . . .  33
       8.4.4.  Measurement Peer <-> Measurement Agent  . . . . . . .  33
       8.4.5.  Passive Measurement Agent . . . . . . . . . . . . . .  34



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       8.4.6.  Storage and Reporting of Measurement Results  . . . .  35
     8.5.  Threats . . . . . . . . . . . . . . . . . . . . . . . . .  35
       8.5.1.  Surveillance  . . . . . . . . . . . . . . . . . . . .  36
       8.5.2.  Stored Data Compromise  . . . . . . . . . . . . . . .  36
       8.5.3.  Correlation and Identification  . . . . . . . . . . .  36
       8.5.4.  Secondary Use and Disclosure  . . . . . . . . . . . .  37
     8.6.  Mitigations . . . . . . . . . . . . . . . . . . . . . . .  37
       8.6.1.  Data Minimisation . . . . . . . . . . . . . . . . . .  37
       8.6.2.  Anonymity . . . . . . . . . . . . . . . . . . . . . .  38
       8.6.3.  Pseudonymity  . . . . . . . . . . . . . . . . . . . .  39
       8.6.4.  Other Mitigations . . . . . . . . . . . . . . . . . .  39
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  40
   10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  40
   11. History . . . . . . . . . . . . . . . . . . . . . . . . . . .  41
     11.1.  From -00 to -01  . . . . . . . . . . . . . . . . . . . .  41
     11.2.  From -01 to -02  . . . . . . . . . . . . . . . . . . . .  41
     11.3.  From -02 to -03  . . . . . . . . . . . . . . . . . . . .  42
   12. Informative References  . . . . . . . . . . . . . . . . . . .  42
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  44

1.  Introduction

   There is a desire to be able to coordinate the execution of broadband
   measurements and the collection of measurement results across a large
   scale set of diverse devices.  These devices could be software based
   agents on PCs, embedded agents in consumer devices (e.g. blu-ray
   players), service provider controlled devices such as set-top players
   and home gateways, or simply dedicated probes.  It is expected that
   such a system could easily comprise 100k devices.  Such a scale
   presents unique problems in coordination, execution and measurement
   result collection.  Several use cases have been proposed for large-
   scale measurements including:

   o  Operators: to help plan their network and identify faults

   o  Regulators: to benchmark several network operators and support
      public policy development

   Further details of the use cases can be found at
   [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
   concentrate on, such as to help end users run diagnostic checks like
   a network speed test.

   The LMAP framework has four basic elements: Measurement Agents,
   Measurement Peers, Controllers and Collectors.





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   Measurement Agents (MAs) perform Measurement Tasks, perhaps in
   conjunction with Measurement Peers.  They are pieces of code that can
   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
   Measurement Tasks it should perform and when.  For example it may
   instruct a MA at a home gateway: "Measure the 'UDP latency' with the
   Measurement Peer mp.example.org; repeat every hour at xx.05".  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".  We refer to these as the Measurement Schedule and
   Report Schedule.

   The Collector accepts Reports from the MAs with the Results from
   their Measurement Tasks.  Therefore the MA is a device that gets
   Instructions from the Controller, initiates the Measurement Tasks,
   and reports to the Collector.

   There are additional elements that are part of a measurement system,
   but that are out of the scope for LMAP.  We provide a detailed
   discussion of all the elements in the rest of the document.

   The desirable features for a large-scale measurement systems we are
   designing for are:

   o  Standardised - in terms of the Measurement Tasks that they
      perform, the components, the data models and protocols for
      transferring information between the components.  Amongst other
      things, standardisation enables meaningful comparisons of
      measurements made of the same metric at different times and
      places, and enables the operator of a measurement system to buy
      the various components from different vendors.  Today's systems
      are proprietary in some or all of these aspects.




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   o  Large-scale - [I-D.ietf-lmap-use-cases] envisages Measurement
      Agents in every home gateway and edge device such as set-top-boxes
      and tablet computers.  It is expected that a measurement system
      could easily encompass a few hundred thousand Measurement Agents.
      Existing systems have up to a few thousand MAs (without judging
      how much further they could scale).

   o  Diversity - a measurement system should handle different types of
      Measurement Agent - for example Measurement Agents may come from
      different vendors, be in wired and wireless networks and be on
      devices with IPv4 or IPv6 addresses.

2.  Outline of an LMAP-based measurement system

   Figure 1 shows the main components of a measurement system, and the
   interactions of those components.  Some of the components are outside
   the scope of LMAP.  In this section we provide an overview of the
   whole measurement system and we introduce the main terms needed for
   the LMAP framework.  The new terms are capitalized.  In the next
   section we provide a terminology section with a compilation of all
   the LMAP terms and their definition.  The subsequent sections study
   the LMAP components in more detail.

   A Measurement Task measures some performance or reliability Metric of
   interest.  An Active Measurement Task involves either a Measurement
   Agent (MA) injecting Active Measurement Traffic into the network
   destined for a Measurement Peer, and/or a Measurement Peer 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 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
   Method is a generalisation of a Measurement Task), so that it is
   meaningful to compare measurements of the same Metric made at
   different times and places.  It is also useful to define a registry
   for commonly-used Metrics [I-D.bagnulo-ippm-new-registry-independent]
   so that a Measurement Method can be referred to simply by its
   identifier in the registry.  The Measurement Methods and registry
   will hopefully be referenced by other standards organisations.

   In order for a Measurement Agent and a Measurement Peer to execute an
   Active Measurement Task, they exchange Active Measurement Traffic.
   The protocols used for the Active Measurement Traffic is out of the
   scope of the LMAP WG and falls within the scope of other IETF WGs
   such as IPPM.




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   For Measurement Results to be truly comparable, as might be required
   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
   Measurement Schedule and be of similar number.  The details of such a
   characterisation plan are beyond the scope of work in IETF although
   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
   LMAP WG and will be provided through existing protocols or
   applications.  They affect how the measurement system uses the
   Measurement Results and how it decides what set of Measurement Tasks
   to perform.

   The MA needs to be bootstrapped with initial details about its
   Controller, including authentication credentials.  The LMAP WG
   considers the bootstrap process, since it affects the Information
   Model.  However, it does not define a bootstrap protocol, since it is
   likely to be technology specific and could be defined by the
   Broadband Forum, CableLabs or IEEE depending on the device.  Possible
   protocols are SNMP, NETCONF or (for Home Gateways) CPE WAN Management
   Protocol (CWMP) from the Auto Configuration Server (ACS) (as
   specified in TR-069).




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   A Subscriber parameter database contains information about the line,
   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
   located, and the type of home gateway and MA.  These parameters are
   already gathered and stored by existing operations systems.  They may
   affect the choice of what Measurement Tasks to run and how to
   interpret the Measurement Results.  For example, a download test
   suitable for a line with an 80Mb/s contract may overwhelm a 2Mb/s
   line.

   A results repository records all Measurement Results in an equivalent
   form, for example an SQL database, so that they can easily be
   accessed by the data analysis tools.  The data analysis tools also
   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 Results repository.  They might visualise the data or identify
   which component or link is likely to be the cause of a fault or
   degradation.  This information could help the Controller decide what
   follow-up Measurement Task to perform in order to diagnose a fault.

   The operator's OAM (Operations, Administration, and Maintenance) uses
   the results from the tools.



























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                                                                 ^
                                                                 |
                                    Active                       IPPM
               +---------------+  Measurement +-------------+    Scope
      +------->| Measurement   |<------------>| Measurement |    v
      |        |   Agent       |   Traffic    |     Peer    |    ^
      |        +---------------+              +-------------+    |
      |              ^      |                                    |
      |  Instruction |      |  Report                            |
      |              |      +-----------------+                  |
      |              |                        |                  |
      |              |                        v                  LMAP
      |         +------------+             +------------+        Scope
      |         | Controller |             |  Collector |        |
      |         +------------+             +------------+        v
      |                ^   ^                       |             ^
      |                |   |                       |             |
      |                |   +----------+            |             |
      |                |              |            v             |
   +------------+   +----------+    +--------+    +----------+   |
   |Bootstrapper|   |Subscriber|--->|  data  |<---|repository|   Out
   +------------+   |parameter |    |analysis|    +----------+   of
                    |database  |    | tools  |                   Scope
                    +----------+    +--------+                   |
                                                                 |
                                                                 v

   Figure 1: Schematic of main elements of an LMAP-based
   measurement system
   (showing the elements in and out of the scope of the LMAP WG)

3.  Terminology

   This section defines terminology for LMAP.  Please note that defined
   terms are capitalized.

   Active Measurement Method (Task): A type of Measurement Method (Task)
   that involves a Measurement Agent and a Measurement Peer (or possibly
   Peers), where either the Measurement Agent or the Measurement Peer
   injects Active Measurement Traffic into the network destined for the
   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
   Measurement Agent and/or the Measurement Peer, as part of an Active
   Measurement Task.





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   Bootstrap: A process that initialises a Measurement Agent with the
   information necessary to be integrated into a measurement system.

   Capabilities: Information about the Measurement Methods that the MA
   can perform and the device hosting the MA, for example its interface
   type and speed and its IP address.

   Channel: an Instruction Channel, Report Channel or MA-to-Controller
   Channel

   Collector: A function that receives a Report from a Measurement
   Agent.

   Composite Metric: A Metric that is a combination of other Metrics,
   and/or a combination of the same Metric measured over different parts
   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
   MA, which is defined by a specific Controller, MA and associated
   security, and over which Instructions are sent.

   Control Protocol: The protocol delivering Instruction(s) from a
   Controller to a Measurement Agent.  It also delivers Failure
   Information and Capabilities Information from the Measurement Agent
   to the Controller.

   Cycle-ID: (optional) A tag that is sent by the Controller in an
   Instruction and echoed by the MA in its Report.  The same Cycle-ID is
   used by several MAs that use the same Measurement Method with the
   same Input Parameters.  Hence the Cycle-ID allows the Collector to
   easily identify Measurement Results that should be comparable.

   Data Model: The implementation of an Information Model in a
   particular data modelling language.

   Environmental Constraint: A parameter that is measured as part of the
   Measurement Task, its value determining whether the rest of the
   Measurement Task proceeds.

   Failure Information: Information about the MA's failure to action or
   execute an Instruction, whether concerning Measurement Tasks or
   Reporting.

   Group-ID: (optional) An identifier of a group of MAs.




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   Information Model: The protocol-neutral definition of the semantics
   of the Instructions, the Report, the status of the different elements
   of the measurement system as well of the events in the system.

   Input Parameter: A parameter whose value is left open by the
   Measurement Method and is set to a specific value in a Measurement
   Task.  Altering the value of an Input Parameter does not change the
   fundamental nature of the Measurement Method.

   Instruction: The description of Measurement Tasks to perform and the
   details of the Report to send.  The Instruction is sent by a
   Controller to a Measurement Agent.

   MA-to-Controller Channel: a communications channel between a MA and a
   Controller, which is defined by a specific Controller, MA and
   associated security, and over which Capabilities and Failure
   Information is sent.

   Measurement Agent (MA): The function that receives Instructions from
   a Controller, performs Measurement Tasks (perhaps in concert with a
   Measurement Peer) and reports Measurement Results to a Collector.

   Measurement Agent Identifier (MA-ID): a UUID [RFC4122], which is
   configured as part of the Bootstrapping and included in a
   Capabilities message, Failure Information message and optionally in a
   Report.

   Measurement Method: The process for assessing the value of a Metric;
   the process of measuring some performance or reliability parameter;
   the generalisation of a Measurement Task.

   Measurement Peer: The function that receives control messages and
   Active Measurement Traffic from a Measurement Agent and may reply to
   the Measurement Agent as defined by the Active Measurement Method.

   Measurement Result: The output of a single Measurement Task (the
   value obtained for the parameter of interest or Metric).

   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;
   the act consisting of the (single) operation of the Measurement
   Method at a particular time and with all its parameters set to
   specific values.




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   Metric: The quantity related to the performance and reliability of
   the network that we'd like to know the value of, and that is
   carefully specified.

   Passive Measurement Method (Task): A Measurement Method (Task) in
   which a Measurement Agent observes existing traffic but does not
   inject Active Measurement Traffic.

   Report: The Measurement Results and other associated information (as
   defined by the Instruction).  The Report is sent by a Measurement
   Agent to a Collector.

   Report Channel: a communications channel between a MA and a
   Collector, which is defined by a specific MA, Collector, Report
   Schedule and associated security, and over which Reports are sent.

   Report Protocol: The protocol delivering Report(s) from a Measurement
   Agent to a Collector.

   Report Schedule: the schedule for sending one or more Reports to a
   Collector.

   Subscriber: An entity (associated with one or more users) that is
   engaged in a subscription with a service provider.  The Subscriber is
   allowed to subscribe and un-subscribe services, and to register a
   user or a list of users authorized to enjoy these services.  [Q1741]
   Both the Subscriber and service provider are allowed to set the
   limits relative to the use that associated users make of subscribed
   services.

4.  Constraints

   The LMAP framework makes some important assumptions, which constrain
   the scope of the work to be done.

4.1.  Measurement system is under the direction of a single organisation

   In the LMAP framework, the measurement system is under the direction
   of a single organisation that is responsible both for the data and
   the quality of experience delivered to its users.  Clear
   responsibility is critical given that a misbehaving large-scale
   measurement system could potentially harm user experience, user
   privacy and network security.

   However, the components of an LMAP measurement system can be deployed
   in administrative domains that are not owned by the measuring
   organisation.  Thus, the system of functions deployed by a single




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   organisation constitutes a single LMAP domain which may span
   ownership or other administrative boundaries.

4.2.  Each MA may only have a single Controller at any point in time

   A MA is instructed by one Controller and is in one measurement
   system.  The constraint avoids different Controllers giving a MA
   conflicting instructions and so means that the MA does not have to
   manage contention between multiple Measurement (or Report) Schedules.
   This simplifies the design of MAs (critical for a large-scale
   infrastructure) and allows a Measurement Schedule to be tested on
   specific types of MA before deployment to ensure that the end user
   experience is not impacted (due to CPU, memory or broadband-product
   constraints).

   An operator may have several Controllers, perhaps with a Controller
   for different types of MA (home gateways, tablets) or location
   (Ipswich, Edinburgh).

5.  LMAP Protocol Model

   A protocol model [RFC4101] presents an architectural model for how
   the protocol operates and needs to answer three basic questions:

   1.  What problem is the protocol trying to achieve?

   2.  What messages are being transmitted and what do they mean?

   3.  What are the important, but unobvious, features of the protocol?

   An LMAP system goes through the following phases:

   o  a bootstrapping process before the MA can take part in the other
      three phases

   o  a Control Protocol, which delivers an Instruction from a
      Controller to a MA, detailing what Measurement Tasks the MA should
      perform and when, and how it should report the Measurement Results

   o  the actual Measurement Tasks are performed.  An Active Measurement
      Task involves sending Active Measurement Traffic between the
      Measurement Agent and a Measurement Peer, whilst a Passive
      Measurement Task involves (only) the Measurement Agent observing
      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
      Collector.  The Report contains the Measurement Results.



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   In the diagrams the following convention is used:

   o  (optional): indicated by round brackets

   o  [potentially repeated]: indicated by square brackets

   The protocol model is closely related to the Information Model
   [I-D.burbridge-lmap-information-model], which is the abstract
   definition of the information carried by the protocol model.  The
   purpose of both is to provide a protocol and device independent view,
   which can be implemented via specific protocols.  The LMAP WG will
   define a specific Control Protocol and Report Protocol, but others
   could be defined by other standards bodies or be proprietary.
   However it is important that they all implement the same Information
   Model and protocol model, in order to ease the definition, operation
   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

   The primary purpose of bootstrapping is to enable the MA and
   Controller to be integrated into a measurement system.  In order to
   do that, the MA needs to retrieve information about itself (like its
   identity in the measurement system), about the Controller, as well as
   security information (such as certificates and credentials).
























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                                                        +--------------+
                                                        | Measurement  |
                                                        |  Agent       |
                                                        +--------------+
   (initial Controller details:
    address or FQDN,                      ->
    security credentials)

   +-----------------+
   |    initial      |
   |   Controller    |
   +-----------------+
                                          <-              (register)

   Controller details:
    address or FQDN,                      ->
    security credentials

   +-----------------+
   |                 |
   |   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
   specific mechanism.  For example, this could be in the firmware,
   downloaded, manually configured or via a protocol like TR-069.  The
   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
   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
   receive Instructions from the Controller, in particular the
   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-



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   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
   Measurement Methods it can perform.

   If the device with the MA re-boots, then the MA needs to re-register,
   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
   scope to define a bootstrap mechanism, as it depends on the type of
   device and access.

5.2.  Control Protocol

   The primary purpose of the Control Protocol is to allow the
   Controller to configure a Measurement Agent with an Instruction about
   what Measurement Tasks to do, when to do them, and how to report the
   Measurement Results.  The Measurement Agent then acts on the
   Instruction autonomously.

+-----------------+                                   +-------------+
|                 |                                   | Measurement |
|  Controller     |===================================|  Agent      |
+-----------------+                                   +-------------+

(Capabilities request)                   ->
                                         <-            Capabilities
ACK                                      ->


Instruction:
[(Measurement Task (Input Parameters)),  ->
 (Measurement Schedule),
 (Report Channel(s))]
                                         <-              ACK


                                         <-         Failure Information:
                                                    [reason]
ACK                                      ->





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   The Controller needs to know the Capabilities of the MA, and in
   particular what Measurement Methods it supports, so that it can
   correctly instruct the MA.  It is possible that the Controller knows
   the MA's Capabilities via some mechanism beyond the scope of LMAP,
   such as a device-specific protocol.  In LMAP, the MA can inform the
   Controller about its Capabilities.  This message could be sent in
   several circumstances: when the MA first communicates with a
   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 following elements:

   o  configuration of all the Measurement Tasks, each of which needs:

      *  the Measurement Method, specified as a URN to a registry entry.
         The registry could be defined by the IETF
         [I-D.bagnulo-ippm-new-registry-independent], locally by the
         operator of the measurement system or perhaps by another
         standards organisation.

      *  any Input Parameters that need to be set for the Measurement
         Method, such as the address of the Measurement Peer

      *  if the device with the MA has multiple interfaces, then the
         interface to use

      *  optionally, a Cycle-ID

      *  a name for this Measurement Task configuration

   o  configuration of all the Report Channels, each of which needs:

      *  the address of the Collector, for instance its URL

      *  the timing of when to report Measurement Results, for example
         every hour or immediately

      *  security for sending the Report, for example the X.509
         certificate

      *  a name for this Report Channel

   o  the set of periodic Measurement Schedules, each of which needs:



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      *  the name of one or several Measurement Task configurations

      *  the timing of when the Measurement Tasks are to be performed.
         Possible types of timing are periodic and calendar-based
         periodic

      *  the name of a Report Channel or Channels on which to report the
         Measurement Results

      *  a name for this Measurement Schedule

   o  the set of one-off Measurement Schedules, each of which needs the
      same items as for a periodic Measurement Schedule, except that the
      possible types of timing are one-off immediate and one-off at a
      future time.

   A single Instruction message contains one, two, three or all four of
   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
   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
   Measurement Task configurations that are to be carried out on a
   recurring basis, whilst one-off Measurement Schedules contain non-
   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
   not allow the MA to negotiate, as this would add complexity to the
   MA, Controller and Control Protocol for little benefit.

   The MA can inform the Controller about a Failure.  There are two
   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



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   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
   successfully.

   Finally, note that the MA doesn't do a 'safety check' with the
   Controller (that it should still continue with the requested
   Measurement Tasks) - nor does it inform the Controller about
   Measurement Tasks starting and stopping.  It simply carries out the
   Measurement Tasks as instructed, unless it gets an updated
   Instruction.

   The LMAP WG will define a Control Protocol and its associated Data
   Model that implements the Protocol & Information Model.  This may be
   a simple instruction-response protocol.

5.2.1.  Measurement Suppression

   Measurement Suppression is used if the measurement system wants to
   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
      suppressed.  For example, a particular Measurement Task may be
      overloading a Measurement Peer.

   o  a set of Measurement Schedules to suppress; the others are not
      suppressed.  For example, suppose the measurement system has
      defined two Schedules, one with the most critical Active
      Measurement Tasks and the other with less critical ones that
      create a lot of traffic, then it may only want to suppress the
      second.

   o  a start time, at which suppression begins

   o  an end time, at which suppression ends.

   It is not standardised what the impact of Suppression is on:





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   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

   Note that Suppression is not intended to permanently stop a
   Measurement Task (instead, the Controller should send a new
   Measurement Schedule), nor to permanently disable a MA (instead, some
   kind of management action is suggested).

   +-----------------+                                   +-------------+
   |                 |                                   | Measurement |
   |  Controller     |===================================|  Agent      |
   +-----------------+                                   +-------------+

   Suppress:
   [(Measurement Task),                     ->
    (Measurement Schedule),
    start time, end time]
                                            <-              ACK

   Un-suppress                              ->
                                            <-              ACK


5.3.  Starting and stopping Measurement Tasks

   The LMAP WG is neutral to what the actual Measurement Task is.  The
   WG does not define a generic start and stop process, since the
   correct approach depend on the particular Measurement Task; the
   details are defined as part of each Measurement Method, and hence
   potentially by the IPPM WG.  This section provides some general
   hints.

   Once the MA gets its Measurement and Report Schedules from its
   Controller then it acts autonomously, in terms of operation of the
   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
   traffic is sent.  Action could include:

   o  the MA checking that there is no cross-traffic; in other words, a
      check that the user isn't already sending traffic;




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   o  the MA checking with the Measurement Peer that it can handle a new
      Measurement Task (in case the Measurement Peer is already handling
      many Measurement Tasks with other MAs);

   o  the first part of the Measurement Task consisting of traffic that
      probes the path to make sure it isn't overloaded.

   It is possible that similar checks continue during the Measurement
   Task, especially one that is long-running and/or creates a lot of
   Active Measurement Traffic, which may be abandoned whilst in-
   progress.  A Measurement Task could also be abandoned in response to
   a "suppress" message (see Section 5.2.1).  Action could include:

   o  For 'upload' tests, the MA not sending traffic

   o  For 'download' tests, the MA closing the TCP connection or sending
      a TWAMP Stop control message [RFC5357].

   The Controller may want a MA to run the same Measurement Task
   indefinitely (for example, "run the 'upload speed' Measurement Task
   once an hour until further notice").  To avoid the MA generating
   traffic forever after a Controller has permanently failed, it is
   suggested that the Measurement Schedule includes a time limit ("run
   the 'upload speed' Measurement Task once an hour for the next 30
   days") and that the Measurement Schedule is updated regularly (say,
   every 10 days).

   {Comment: It is possible that the set of measurement schedules
   implies overlapping Measurement Tasks.  It is not clear the best
   thing to do.  Our current suggestion is to leave this to the protocol
   document.}

5.4.  Report Protocol

   The primary purpose of the Report Protocol is to allow a Measurement
   Agent to report its Measurement Results to a Collector, and the
   context in which they were obtained.














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  +-----------------+                                   +-------------+
  |                 |                                   | Measurement |
  |   Collector     |===================================|  Agent      |
  +-----------------+                                   +-------------+

                                     <-          Report:
                                                   [MA-ID &/or Group-ID,
                                                    Measurement Results,
                                            details of Measurement Task]
  ACK                                ->


   The Report contains:

   o  the MA-ID or a Group-ID (to anonymise results)

   o  the actual Measurement Results, including the time they were
      measured

   o  the details of the Measurement Task (to avoid the Collector having
      to ask the Controller for this information later)

   The MA sends Reports as defined by the Report Channel in the
   Controller's Instruction.  It is possible that the Instruction tells
   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
   also possible that a Measurement Task may create two (or more)
   Measurement Results, which could be reported differently (for
   example, one Result could be reported periodically, whilst the second
   Result could be an alarm that is created as soon as the measured
   value of the Metric crosses a threshold and that is reported
   immediately).

   Optionally, a Report is not sent when there are no Measurement
   Results.

   In the initial LMAP Information Model and Report Protocol, for
   simplicity we assume that all Measurement Results are reported as-is,
   but allow extensibility so that a measurement system (or perhaps a
   second phase of LMAP) could allow a MA to pre-process Measurement
   Results before it reports them.  Potential examples of pre-processing
   by the MA are:

   o  labelling, or perhaps not including, Measurement Results impacted
      by, for instance, cross-traffic or the Measurement Peer being busy

   o  not reporting the Measurement Results if the MA believes that they
      are invalid



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   o  detailing when suppression started and ended

   o  filtering outlier Results

   o  calculating some statistic like average (beyond that defined by
      the Measurement Task itself)

   The measurement system may define what happens if a Collector
   unexpectedly does not hear from a MA, for example the Controller
   could send a fresh Report Schedule to the MA.

   The LMAP WG will define a Report Protocol and its associated Data
   Model that implements the Information Model and protocol model.  This
   may be a simple instruction-response protocol.

5.5.  Operation of LMAP over the underlying transport protocol

   The above sections have described LMAP's protocol model.  The LMAP
   working group will also specify how it operates over an existing
   protocol, to be selected, for example REST-style HTTP(S).  It is also
   possible that a different choice is made for the Control and Report
   Protocols, for example NETCONF-YANG and IPFIX respectively.  It is
   even possible that a different choice could be made for Suppression
   and for other Instruction messages.

   For the Control Protocol, the underlying transport protocol could be:

   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 'pull' protocol.  The MA periodically checks with Controller if
      the Instruction has changed and pulls a new Instruction if
      necessary.  A pull protocol seems attractive for a MA behind a NAT
      (as is typical for a MA on an end-user's device), so that it can
      initiate the communications.  A pull mechanism is likely to
      require the MA to be configured with how frequently it should
      check in with the Controller, and perhaps what it should do if the
      Controller is unreachable after a certain number of attempts.

   o  a hybrid protocol.  In addition to a pull protocol, the Controller
      can also push an alert to the MA that it should immediately pull a
      new Instruction.

   For the Report Protocol, the underlying transport protocol could be:

   o  a 'push' protocol (that is, from the MA to the Collector)




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   o  perhaps supplemented by the ability for the Collector to 'pull'
      Measurement Results from a MA.

5.6.  Items beyond the scope of the LMAP Protocol Model

   There are several potential interactions between LMAP elements that
   are out of scope of definition by the LMAP WG:

   1.  It does not define a coordination process between MAs.  Whilst a
       measurement system may define coordinated Measurement Schedules
       across its various MAs, there is no direct coordination between
       MAs.

   2.  It does not define interactions between the Collector and
       Controller.  It is quite likely that there will be such
       interactions, optionally intermediated by the data analysis
       tools.  For example if there is an "interesting" Measurement
       Result then the measurement system may want to trigger extra
       Measurement Tasks that explore the potential cause in more
       detail.

   3.  It does not define coordination between different measurement
       systems.  For example, it does not define the interaction of a MA
       in one measurement system with a Controller or Collector in a
       different measurement system.  Whilst it is likely that the
       Control and Report Protocols could be re-used or adapted for this
       scenario, any form of coordination between different
       organisations involves difficult commercial and technical issues
       and so, given the novelty of large-scale measurement efforts, any
       form of inter-organisation coordination is outside the scope of
       the LMAP WG.  Note that a single MA is instructed by a single
       Controller and is only in one measurement system.

       *  An interesting scenario is where a home contains two
          independent MAs, for example one controlled by a regulator and
          one controlled by an ISP.  Then the Active Measurement Traffic
          of one MA is treated by the other MA just like any other user
          traffic.

   4.  It does not consider how to prevent a malicious party "gaming the
       system".  For example, where a regulator is running a measurement
       system in order to benchmark operators, a malicious operator
       could try to identify the broadband lines that the regulator was
       measuring and prioritise that traffic.  It is assumed this is a
       policy issue and would be dealt with through a code of conduct
       for instance.





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   5.  It does not define how to analyse Measurement Results, including
       how to interpret missing Results.

   6.  It does not specifically define a enduser-controlled measurement
       system, see sub-section 5.6.1.

5.6.1.  Enduser-controlled measurement system

   The WG concentrates on the cases where an ISP or a regulator runs the
   measurement system.  However, we expect that LMAP functionality will
   also be used in the context of an enduser-controlled measurement
   system.  There are at least two ways this could happen (they have
   various pros and cons):

   1.  an enduser could somehow request the ISP- (or regulator-) run
       measurement system to test his/her line.  The ISP (or regulator)
       Controller would then send an Instruction to the MA in the usual
       LMAP way.  Note that a user can't directly initiate a Measurement
       Task on an ISP- (or regulator-) controlled MA.

   2.  an enduser could deploy their own measurement system, with their
       own MA, Controller and Collector.  For example, the user could
       implement all three functions onto the same enduser-owned end
       device, perhaps by downloading the functions from the ISP or
       regulator.  Then the LMAP Control and Report Protocols do not
       need to be used, but using LMAP's Information Model would still
       be beneficial.  The Measurement Peer could be in the home gateway
       or outside the home network; in the latter case the Measurement
       Peer is highly 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
   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
   text message.  Presumably the user will also be able to see the
   Measurement Results, perhaps summarised on a webpage.  It is
   suggested that these interfaces conform to the LMAP guidance on the
   privacy in Section 8.

6.  Deployment considerations

6.1.  Controller

   The Controller should understand both the MA's LMAP Capabilities (for
   instance what Measurement Methods it can perform) and about the MA's
   other capabilities like processing power and memory.  This allows the
   Controller to make sure that the Measurement Schedule of Measurement




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   Tasks and the Reporting Schedule are sensible for each MA that it
   Instructs.

   An Instruction is likely to include several Measurement Tasks.
   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
   will not affect the Results of another Task.

   The Controller should ensure that the Active Measurement Tasks do not
   have an adverse effect on the end user.  Typically Tasks, especially
   those that generate a substantial amount of traffic, will include a
   pre-check that the user isn't already sending traffic (Section 5.3).
   Another consideration is whether Active Measurement Traffic will
   impact a Subscriber's bill or traffic cap.

   The different elements of the Instruction can be updated
   independently.  For example, the Measurement Tasks could be
   configured with different Input Parameters whilst keeping the same
   Measurement Schedule.  In general this should not create any issues,
   since Measurement Methods should be defined so their fundamental
   nature does not change for a new value of Input Parameter.  There
   could be a problem if, for example, a Measurement Task involving a
   1kB file upload could be changed into a 1GB file upload.

   A measurement system may have multiple Controllers (but note the
   overriding principle that a single MA is instructed by a single
   Controller at any point in time (Section 4.2)).  For example, there
   could be different Controllers for different types of MA (home
   gateways, tablets) or locations (Ipswich, Edinburgh), for load
   balancing or to cope with failure of one Controller.  One possibility
   is that Bootstrapping involves an initial Controller, whose role is
   simply to inform the MA how to contact its actual Controller.

6.2.  Measurement Agent

   The Measurement Agent could take a number of forms: a dedicated
   probe, software on a PC, embedded into an appliance, or even embedded
   into a gateway.  A single site (home, branch office etc.) that is
   participating in a measurement could make use of one or multiple
   Measurement Agents in a single measurement.  If the site is multi
   homed there might be a Measurement Agent per interface.

   The Measurement Agent could be deployed in a variety of locations.
   Not all deployment locations are available to every kind of
   Measurement Agent.  There are also a variety of limitations and
   trade-offs depending on the final placement.  The next sections
   outline some of the locations a Measurement Agent may be deployed.
   This is not an exhaustive list and combinations may also apply.



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   If the Instruction includes several Measurement Tasks, these could be
   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
   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.

6.2.1.  Measurement Agent embedded in site gateway

   A Measurement Agent embedded with the site gateway, for example a
   home router or the edge router of a branch office in a managed
   service environment, is one of better places the Measurement Agent
   could be deployed.  All site-to-ISP traffic would traverse through
   the gateway and passive measurements could easily be performed.
   Similarly, due to this user traffic visibility, an Active
   Measurements Task could be rescheduled so as not to compete with user
   traffic.  Generally NAT and firewall services are built into the
   gateway, allowing the Measurement Agent the option to offer its
   Controller 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.
   However, if the site gateway is owned and operated by the service
   provider, the Measurement Agent will generally not be directly
   available for over the top providers, the regulator, end users or
   enterprises.

6.2.2.  Measurement Agent embedded behind site NAT /Firewall

   The Measurement Agent could also be embedded behind a NAT, a
   firewall, or both.  In this case the Controller may not be able to
   unilaterally contact the Measurement Agent unless either static port
   forwarding configuration or firewall pin holing is configured, and
   might not always be possible.  It would require user intervention or
   pre-provisioning by the operator via a mechanisms such as TR-069.
   The Measurement Agent may originate a session towards the Controller
   and maintain the session for bidirectional communications.  This
   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.



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6.2.3.  Measurement Agent in a multi-homed site

   A broadband site may be multi-homed.  For example, the site may be
   connected to multiple broadband ISPs, perhaps for redundancy or load-
   sharing, or have both wired and wireless broadband connectivity.  It
   may also be helpful to think of dual stack IPv4 and IPv6 broadband
   devices as multi-homed.  In these cases, there needs to be clarity on
   which network connectivity option is being measured.  Sometimes this
   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
   WAN side interface), there is little confusion or choice.  However,
   for multi-homed gateways or devices behind the gateway(s) of multi-
   homed sites it would be preferable to explicitly select the network
   to measure ([RFC5533]) but the network measured should be included in
   the Measurement Result.  Section 3.2 of [I-D.ietf-homenet-arch]
   describes dual-stack and multi-homing topologies that might be
   encountered in a home network (which is generally a broadband
   connected site).  The Multiple Interfaces (mif) working group covers
   cases where hosts are either directly attached to multiple networks
   (physical or virtual) or indirectly (multiple default routers, etc.).
   [RFC6419] provides the current practices of multi-interfaces hosts
   today.  As one aim is for a MA is to measure the end user's quality
   of experience, it is important to understand the current practices.

6.3.  Measurement Peer

   A Measurement Peer participates in Active Measurement Tasks.  It may
   have specific functionality to enable it to participate in a
   particular Measurement Method.  On the other hand, other Measurement
   Methods may require no special functionality, for example if the
   Measurement Agent sends a ping to example.com then the server at
   example.com plays the role of a Measurement Peer.

   A device may participate in some Measurement Tasks as a Measurement
   Agent and in others as a Measurement Peer.

7.  Security considerations

   The security of the LMAP framework should protect the interests of
   the measurement operator(s), the network user(s) and other actors who
   could be impacted by a compromised measurement deployment.  The
   measurement system must secure the various components of the system
   from unauthorised access or corruption.

   We assume that each Measurement Agent (MA) will receive its
   Instructions from a single organisation, which operates the
   Controller.  These Instructions must be authenticated (to ensure that
   they come from the trusted Controller), checked for integrity (to



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   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
   use it to launch DoS attacks at targets, reduce the end user's
   quality of experience and corrupt the Measurement Results that are
   reported to the Collector.  By altering the Measurement Tasks and/or
   the address that Results are reported to, they can also compromise
   the confidentiality of the network user and the MA environment (such
   as information about the location of devices or their traffic).

   Reporting by the MA must also be secured to maintain confidentiality.
   The results must be encrypted such that only the authorised Collector
   can decrypt the results to prevent the leakage of confidential or
   private information.  In addition it must be authenticated that the
   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
   falsified data into the measurement platform or to corrupt the
   results of a real MA.  The results must also be held and processed
   securely after collection and analysis.

   Availability should also be considered.  While the loss of some MAs
   may not be considered critical, the unavailability of the Collector
   could mean that valuable business data or data critical to a
   regulatory process is lost.  Similarly, the unavailability of a
   Controller could mean that the MAs do not operate a correct
   Measurement Schedule.

   A malicious party could "game the system".  For example, where a
   regulator is running a measurement system in order to benchmark
   operators, an operator could try to identify the broadband lines that
   the regulator was measuring and prioritise that traffic.  This
   potential issue is currently handled by a code of conduct.  It is
   outside the scope of the LMAP WG to consider the issue.

8.  Privacy Considerations for LMAP

   The LMAP Working Group will consider privacy as a core requirement
   and will ensure that by default the Control and Report Protocols
   operate in a privacy-sensitive manner and that privacy features are
   well-defined.

   This section provides a set of privacy considerations for LMAP.  This
   section benefits greatly from the timely publication of [RFC6973].
   Privacy and security (Section 7) are related.  In some jurisdictions
   privacy is called data protection.

   We begin with a set of assumptions related to protecting the
   sensitive information of individuals and organisations participating
   in LMAP-orchestrated measurement and data collection.



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8.1.  Categories of Entities with Information of Interest

   LMAP protocols need to protect the sensitive information of the
   following entities, including individuals and organisations who
   participate in measurement and collection of results.

   o  Individual Internet users: Persons who utilise Internet access
      services for communications tasks, according to the terms of
      service of a service agreement.  Such persons may be a service
      Subscriber, or have been given permission by the Subscriber to use
      the service.

   o  Internet service providers: Organisations who offer Internet
      access service subscriptions, and thus have access to sensitive
      information of individuals who choose to use the service.  These
      organisations desire to protect their Subscribers and their own
      sensitive information which may be stored in the process of
      performing Measurement Tasks and collecting and Results.

   o  Regulators: Public authorities responsible for exercising
      supervision of the electronic communications sector, and which may
      have access to sensitive information of individuals who
      participate in a measurement campaign.  Similarly, regulators
      desire to protect the participants and their own sensitive
      information.

   o  Other LMAP system operators: Organisations who operate measurement
      systems or participate in measurements in some way.

   Although privacy is a protection extended to individuals, we include
   discussion of ISPs and other LMAP system operators in this section.
   These organisations have sensitive information involved in the LMAP
   system, and many of the same dangers and mitigations are applicable.
   Further, the ISPs store information on their Subscribers beyond that
   used in the LMAP system (for instance billing information), and there
   should be a benefit in considering all the needs and potential
   solutions coherently.

8.2.  Examples of Sensitive Information

   This section gives examples of sensitive information which may be
   measured or stored in a measurement system, and which is to be kept
   private by default in the LMAP core protocols.

   Examples of Subscriber or authorised Internet user sensitive
   information:





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   o  Sub-IP layer addresses and names (MAC address, base station ID,
      SSID)

   o  IP address in use

   o  Personal Identification (real name)

   o  Location (street address, city)

   o  Subscribed service parameters

   o  Contents of traffic (activity, DNS queries, destinations,
      equipment types, account info for other services, etc.)

   o  Status as a study volunteer and Schedule of (Active) Measurement
      Tasks

   Examples of Internet Service Provider sensitive information:

   o  Measurement device identification (equipment ID and IP address)

   o  Measurement Instructions (choice of measurements)

   o  Measurement Results (some may be shared, others may be private)

   o  Measurement Schedule (exact times)

   o  Network topology (locations, connectivity, redundancy)

   o  Subscriber billing information, and any of the above Subscriber
      information known to the provider.

   o  Authentication credentials (such as certificates)

   Other organisations will have some combination of the lists above.
   The LMAP system would not typically expose all of the information
   above, but could expose a combination of items which could be
   correlated with other pieces collected by an attacker (as discussed
   in the section on Threats below).

8.3.  Key Distinction Between Active and Passive Measurement Tasks

   Passive and Active Measurement Tasks raise different privacy issues.

   Passive Measurement Tasks are conducted on a user's traffic, such
   that sensitive information is present and stored in the measurement
   system (however briefly this storage may be).  We note that some
   authorities make a distinction on time of storage, and information



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   that is kept only temporarily to perform a communications function is
   not subject to regulation (for example, active queue management, deep
   packet inspection).  Passive Measurement Tasks could reveal all the
   websites a Subscriber visits and the applications and/or services
   they use.

   Active Measurement Tasks are conducted on traffic which is created
   specifically for the purpose.  Even if a user host generates Active
   Measurement Traffic, there is significantly limited sensitive
   information about the Subscriber present and stored in the
   measurement system compared to the passive case, as follows:

   o  IP address in use (and possibly sub-IP addresses and names)

   o  Status as a study volunteer and Schedule of Active Measurement
      Tasks

   On the other hand, for a service provider the sensitive information
   like Measurement Results is the same for Passive and Active
   Measurement Tasks.

   From the Subscriber perspective, both Active and Passive Measurement
   Tasks potentially expose the description of Internet access service
   and specific service parameters, such as subscribed rate and type of
   access.

8.4.  Privacy analysis of the Communications Models

   This section examines each of the protocol exchanges described at a
   high level in Section 5 and some example Measurement Tasks, and
   identifies specific sensitive information which must be secured
   during communication for each case.  With the protocol-related
   sensitive information identified, we have can better consider the
   threats described in the following section.

   From the privacy perspective, all entities participating in LMAP
   protocols can be considered "observers" according to the definition
   in [RFC6973].  Their stored information potentially poses a threat to
   privacy, especially if one or more of these functional entities has
   been compromised.  Likewise, all devices on the paths used for
   control, reporting, and measurement are also observers.

8.4.1.  MA Bootstrapping

   Section 5.1 provides the communication model for the Bootstrapping
   process.





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   Although the specification of mechanisms for Bootstrapping the MA are
   beyond the LMAP scope, designers should recognize that the
   Bootstrapping process is extremely powerful and could cause an MA to
   join a new or different LMAP system with a different Controller and
   Collector, or simply install new Measurement Methods (for example to
   passively record DNS queries).  A Bootstrap attack could result in a
   breach of the LMAP system with significant sensitive information
   exposure depending on the capabilities of the MA, so sufficient
   security protections are warranted.

   The Bootstrapping process provides sensitive information about the
   LMAP system and the organisation that operates it, such as

   o  Initial Controller IP address or FQDN

   o  Assigned Controller IP address or FQDN

   o  Security certificates and credentials

   During the Bootstrap process, the MA receives its MA-ID which is a
   persistent pseudonym for the Subscriber in the case that the MA is
   located at a service demarcation point.  Thus, the MA-ID is
   considered sensitive information, because it could provide the link
   between Subscriber identification and Measurements Results.

   Also, the Bootstrap process could assign a Group-ID to the MA.  The
   specific definition of information represented in a Group-ID is to be
   determined, but several examples are envisaged including use as a
   pseudonym for a set of Subscribers, a class of service, an access
   technology, or other important categories.  Assignment of a Group-ID
   enables anonymisation sets to be formed on the basis of service type/
   grade/rates.  Thus, the mapping between Group-ID and MA-ID is
   considered sensitive information.

8.4.2.  Controller <-> Measurement Agent

   The high-level communication model for interactions between the LMAP
   Controller and Measurement Agent is illustrated in Section 5.2.  The
   primary purpose of this exchange is to authenticate and task a
   Measurement Agent with Measurement Instructions, which the
   Measurement Agent then acts on autonomously.

   Primarily IP addresses and pseudonyms (MA-ID, Group-ID) are exchanged
   with a capability request, then measurement-related information of
   interest such as the parameters, schedule, metrics, and IP addresses
   of measurement devices.  Thus, the measurement Instruction contains
   sensitive information which must be secured.  For example, the fact
   that an ISP is running additional measurements beyond the set



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   reported externally is sensitive information, as are the additional
   Measurements Tasks themselves.  The Measurement Schedule is also
   sensitive, because an attacker intending to bias the results without
   being detected can use this information to great advantage.

   An organisation operating the Controller having no service
   relationship with a user who hosts the Measurement Agent *could* gain
   real-name mapping to a public IP address through user participation
   in an LMAP system (this applies to the Measurement Collection
   protocol, as well).

8.4.3.  Collector <-> Measurement Agent

   The high-level communication model for interactions between the
   Measurement Agent and Collector is illustrated in Section 5.4.  The
   primary purpose of this exchange is to authenticate and collect
   Measurement Results from a MA, which the MA has measured autonomously
   and stored.

   The Measurement Results are the additional sensitive information
   included in the Collector-MA exchange.  Organisations collecting LMAP
   measurements have the responsibility for data control.  Thus, the
   Results and other information communicated in the Collector protocol
   must be secured.

8.4.4.  Measurement Peer <-> Measurement Agent

   Although the specification of the mechanisms for an Active
   Measurement Task is beyond the scope of LMAP, it raises potential
   privacy issues.  The high-level communications model below
   illustrates the various exchanges to execute Active Measurement Tasks
   and store the Results.

   We note the potential for additional observers in the figures below
   by indicating the possible presence of a NAT, which has additional
   significance to the protocols and direction of initiation.

   The various messages are optional, depending on the nature of the
   Active Measurement Task.  It may involve sending Active Measurement
   Traffic from the Measurement Peer to MA, MA to Measurement Peer, or
   both.










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    _________________                              _________________
   |                 |                            |                 |
   |Measurement Peer |=========== NAT ? ==========|Measurement Agent|
   |_________________|                            |_________________|

                                  <-              (Key Negotiation &
                                                  Encryption Setup)
   (Encrypted Channel             ->
   Established)
   (Announce capabilities         ->
   & status)
                                  <-              (Select capabilities)
   ACK                            ->
                                  <-              (Measurement Request
                                                 (MA+MP IPAddrs,set of
                                                   Metrics, Schedule))
   ACK                            ->

   Active Measurement Traffic     <>        Active Measurement Traffic
   (may/may not be encrypted)               (may/may not be encrypted)

                                  <-            (Stop Measurement Task)

   Measurement Results            ->
   (if applicable)
                                  <-               ACK, Close

   This exchange primarily exposes the IP addresses of measurement
   devices and the inference of measurement participation from such
   traffic.  There may be sensitive information on key points in a
   service provider's network included.  There may also be access to
   measurement-related information of interest such as the Metrics,
   Schedule, and intermediate results carried in the Active Measurement
   Traffic (usually a set of timestamps).

   If the Active Measurement Traffic is unencrypted, as found in many
   systems today, then both timing and limited results are open to on-
   path observers.

8.4.5.  Passive Measurement Agent

   Although the specification of the mechanisms for a Passive
   Measurement Task is beyond the scope of LMAP, it raises potential
   privacy issues.

   The high-level communications model below illustrates the collection
   of user information of interest with the Measurement Agent performing
   the monitoring and storage of the Results.  This particular exchange



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   is for passive measurement of DNS Response Time, which most
   frequently uses UDP transport.

    _________________                                      ____________
   |                 |                                    |            |
   |  DNS Server     |=========== NAT ? ==========*=======| User client|
   |_________________|                            ^       |____________|
                                            ______|_______
                                           |              |
                                           |  Measurement |
                                           |    Agent     |
                                           |______________|

                                  <-              Name Resolution Req
                                                 (MA+MP IPAddrs,
                                                  Desired Domain Name)
   Return Record                  ->


   This exchange primarily exposes the IP addresses of measurement
   devices and the intent to communicate with or access the services of
   "Domain Name".  There may be information on key points in a service
   provider's network, such as the address of one of its DNS servers.
   The Measurement Agent may be embedded in the user host, or it may be
   located in another device capable of observing user traffic.

   In principle, any of the user sensitive information of interest
   (listed above) can be collected and stored in the passive monitoring
   scenario and so must be secured.

   It would also be possible for a Measurement Agent to source the DNS
   query itself.  But then, as with any active measurement task, there
   are few privacy concerns.

8.4.6.  Storage and Reporting of Measurement Results

   Although the mechanisms for communicating results (beyond the initial
   Collector) are beyond the LMAP scope, there are potential privacy
   issues related to a single organisation's storage and reporting of
   Measurement Results.  Both storage and reporting functions can help
   to preserve privacy by implementing the mitigations described below.

8.5.  Threats

   This section indicates how each of the threats described in [RFC6973]
   apply to the LMAP entities and their communication and storage of
   "information of interest".




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8.5.1.  Surveillance

   Section 5.1.1 of [RFC6973] describes Surveillance as the "observation
   or monitoring of and individual's communications or activities."
   Hence all Passive Measurement Tasks are a form of surveillance, with
   inherent risks.

   Active Measurement Methods which avoid periods of user transmission
   indirectly produce a record of times when a subscriber or authorised
   user has used their network access service.

   Active Measurement Methods may also utilise and store a Subscriber's
   currently assigned IP address when conducting measurements that are
   relevant to a specific Subscriber.  Since the Measurement Results are
   time-stamped, they could provide a record of IP address assignments
   over time.

   Either of the above pieces of information could be useful in
   correlation and identification, described below.

8.5.2.  Stored Data Compromise

   Section 5.1.2 of [RFC6973] describes Stored Data Compromise as
   resulting from inadequate measures to secure stored data from
   unauthorised or inappropriate access.  For LMAP systems this includes
   deleting or modifying collected measurement records, as well as data
   theft.

   The primary LMAP entity subject to compromise is the repository,
   which stores the Measurement Results; extensive security and privacy
   threat mitigations are warranted.  The Collector and MA also store
   sensitive information temporarily, and need protection.  The
   communications between the local storage of the Collector and the
   repository is beyond the scope of the LMAP work at this time, though
   this communications channel will certainly need protection as well as
   the mass storage itself.

   The LMAP Controller may have direct access to storage of Subscriber
   information (location, billing, service parameters, etc.) and other
   information which the controlling organisation considers private, and
   again needs protection.

8.5.3.  Correlation and Identification

   Sections 5.2.1 and 5.2.2 of [RFC6973] describes Correlation as
   combining various pieces of information to obtain desired
   characteristics of an individual, and Identification as using this
   process to infer identity.



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   The main risk is that the LMAP system could unwittingly provide a key
   piece of the correlation chain, starting with an unknown Subscriber's
   IP address and another piece of information.  For example, a
   Subscriber utilised Internet access from 2000 to 2310 UTC, because
   the Active Measurement Tasks were deferred, or sent a name resolution
   for www.example.com at 2300 UTC.

8.5.4.  Secondary Use and Disclosure

   Sections 5.2.3 and 5.2.4 of [RFC6973] describes Secondary Use as
   unauthorised utilisation of an individual's information for a purpose
   the individual did not intend, and Disclosure is when such
   information is revealed causing other's notions of the individual to
   change, or confidentiality to be violated.

   Passive Measurement Tasks are a form of Secondary Use, and the
   Subscribers' permission and the measured ISP's permission should be
   obtained beforehand.  Although user traffic is only indirectly
   involved, the Measurement Results from Active Measurement Tasks
   provide some limited information about the Subscriber/ISP and could
   be used for Secondary Uses.  For example, the use of the Results in
   unauthorised marketing campaigns would qualify as Secondary Use.

8.6.  Mitigations

   This section examines the mitigations listed in section 6 of
   [RFC6973] and their applicability to LMAP systems.  Note that each
   section in [RFC6973] identifies the threat categories that each
   technique mitigates.

8.6.1.  Data Minimisation

   Section 6.1 of [RFC6973] encourages collecting and storing the
   minimal information needed to perform a task.

   There are two levels of information needed for LMAP results to be
   useful for a specific task: troubleshooting and general results
   reporting.

   For general results, the results can be aggregated into large
   categories (the month of March, all subscribers West of the
   Mississippi River).  In this case, all individual identifications
   (including IP address of the MA) can be excluded, and only relevant
   results are provided.  However, this implies a filtering process to
   reduce the information fields, because greater detail was needed to
   conduct the Measurement Tasks in the first place.





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   For troubleshooting, so that a network operator or end user can
   identify a performance issue or failure, potentially all the network
   information (IP addresses, equipment IDs, location), Measurement
   Schedule, service configuration, Measurement Results, and other
   information may assist in the process.  This includes the information
   needed to conduct the Measurements Tasks, and represents a need where
   the maximum relevant information is desirable, therefore the greatest
   protections should be applied.

   We note that a user may give temporary permission for Passive
   Measurement Tasks to enable detailed troubleshooting, but withhold
   permission for them in general.  Here the greatest breadth of
   sensitive information is potentially exposed, and the maximum privacy
   protection must be provided.

   For MAs with access to the sensitive information of users (e.g.,
   within a home or a personal host/handset), it is desirable for the
   results collection to minimise the data reported, but also to balance
   this desire with the needs of troubleshooting when a service
   subscription exists between the user and organisation operating the
   measurements.

   For passive measurements where the MA reports flow information to the
   Collector, the Collector may perform pre-storage minimisation and
   other mitigations (below) to help preserve privacy.

8.6.2.  Anonymity

   Section 6.1.1 of [RFC6973] describes a way in which anonymity is
   achieved: "there must exist a set of individuals that appear to have
   the same attributes as the individual", defined as an "anonymity
   set".

   Experimental methods for anonymisation of user identifiable data
   applicable to Passive Measurement Methods have been identified in
   [RFC6235].  However, the findings of several of the same authors is
   that "there is increasing evidence that anonymisation applied to
   network trace or flow data on its own is insufficient for many data
   protection applications as in [Bur10]."

   Essentially, the details of passive measurement tasks can only be
   accessed by closed organisations, and unknown injection attacks are
   always less expensive than the protections from them.  However, some
   forms of summary may protect the user's sensitive information
   sufficiently well, and so each Metric must be evaluated in the light
   of privacy.





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   The methods in [RFC6235] could be applied more successfully in Active
   Measurement Methods, where there are protections from injection
   attack.  The successful attack would require breaking the integrity
   protection of the LMAP Reporting Protocol and injecting Measurement
   Results (known fingerprint, see section 3.2 of [RFC6973]) for
   inclusion with the shared and anonymised results, then fingerprinting
   those records to ascertain the anonymisation process.

   Beside anonymisation of measured Results for a specific user or
   provider, the value of sensitive information can be further diluted
   by summarising the results over many individuals or areas served by
   the provider.  There is an opportunity enabled by forming anonymity
   sets [RFC6973] based on the reference path measurement points in
   [I-D.ietf-ippm-lmap-path].  For example, all measurements from the
   Subscriber device can be identified as "mp000", instead of using the
   IP address or other device information.  The same anonymisation
   applies to the Internet Service Provider, where their Internet
   gateway would be referred to as "mp190".

8.6.3.  Pseudonymity

   Section 6.1.2 of [RFC6973] indicates that pseudonyms, or nicknames,
   are a possible mitigation to revealing one's true identity, since
   there is no requirement to use real names in almost all protocols.

   A pseudonym for a measurement device's IP address could be an LMAP-
   unique equipment ID.  However, this would likely be a permanent
   handle for the device, and long-term use weakens a pseudonym's power
   to obscure identity.

8.6.4.  Other Mitigations

   Data can be de-personalised by blurring it, for example by adding
   synthetic data, data-swapping, or perturbing the values in ways that
   can be reversed or corrected.

   Sections 6.2 and 6.3 of [RFC6973] describe User Participation and
   Security, respectively.

   Where LMAP measurements involve devices on the Subscriber's premises
   or Subscriber-owned equipment, it is essential to secure the
   Subscriber's permission with regard to the specific information that
   will be collected.  The informed consent of the Subscriber (and, if
   different, the end user) is needed, including the specific purpose of
   the measurements.  The approval process could involve showing the
   Subscriber their measured information and results before instituting
   periodic collection, or before all instances of collection, with the
   option to cancel collection temporarily or permanently.



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   It should also be clear who is legally responsible for data
   protection (privacy); in some jurisdictions this role is called the
   'data controller'.  It is good practice to time limit the storage of
   personal information.

   Although the details of verification would be impenetrable to most
   subscribers, the MA could be architected as an "app" with open
   source-code, pre-download and embedded terms of use and agreement on
   measurements, and protection from code modifications usually provided
   by the app-stores.  Further, the app itself could provide data
   reduction and temporary storage mitigations as appropriate and
   certified through code review.

   LMAP protocols, devices, and the information they store clearly need
   to be secure from unauthorised access.  This is the hand-off between
   privacy and security considerations (Section 7).  The Data Controller
   has the (legal) responsibility to maintain data protections described
   in the Subscriber's agreement and agreements with other
   organisations.

9.  IANA Considerations

   There are no IANA considerations in this memo.

10.  Acknowledgments

   This document is a merger of three individual drafts: draft-eardley-
   lmap-terminology-02, draft-akhter-lmap-framework-00, and draft-
   eardley-lmap-framework-02.

   Thanks to Juergen Schoenwaelder for his detailed review of the
   terminology.  Thanks to Charles Cook for a very detailed review of
   -02.

   Thanks to numerous people for much discussion, directly and on the
   LMAP list (apologies to those unintentionally omitted): Alan Clark,
   Alissa Cooper, Andrea Soppera, Barbara Stark, Benoit Claise, Brian
   Trammell, Charles Cook, Dave Thorne, Frode Soerensen, Greg Mirsky,
   Guangqing Deng, Jason Weil, Jean-Francois Tremblay, Jerome Benoit,
   Joachim Fabini, Juergen Schoenwaelder, Jukka Manner, Ken Ko, Michael
   Bugenhagen, Rolf Winter, Sam Crawford, Sharam Hakimi, Steve Miller,
   Ted Lemon, Timothy Carey, Vaibhav Bajpai, William Lupton.

   Philip Eardley, Trevor Burbridge and Marcelo Bagnulo work in part on
   the Leone research project, which receives funding from the European
   Union Seventh Framework Programme [FP7/2007-2013] under grant
   agreement number 317647.




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11.  History

   First WG version, copy of draft-folks-lmap-framework-00.

11.1.  From -00 to -01

   o  new sub-section of possible use of Group-IDs for privacy

   o  tweak to definition of Control protocol

   o  fix typo in figure in S5.4

11.2.  From -01 to -02

   o  change to INFORMATIONAL track (previous version had typo'd
      Standards track)

   o  new definitions for Capabilities Information and Failure
      Information

   o  clarify that diagrams show LMAP-level information flows.
      Underlying protocol could do other interactions, eg to get through
      NAT or for Collector to pull a Report

   o  add hint that after a re-boot should pause random time before re-
      register (to avoid mass calling event)

   o  delete the open issue "what happens if a Controller fails" (normal
      methods can handle)

   o  add some extra words about multiple Tasks in one Schedule

   o  clarify that new Schedule replaces (rather than adds to) and old
      one.  Similarly for new configuration of Measurement Tasks or
      Report Channels.

   o  clarify suppression is temporary stop; send a new Schedule to
      permanently stop Tasks

   o  alter suppression so it is ACKed

   o  add un-suppress message

   o  expand the text on error reporting, to mention Reporting failures
      (as well as failures to action or execute Measurement Task &
      Schedule)

   o  add some text about how to have Tasks running indefinitely



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   o  add that optionally a Report is not sent when there are no
      Measurement Results

   o  add that a Measurement Task may create more than one Measurement
      Result

   o  clarify /amend /expand that Reports include the "raw" Measurement
      Results - any pre-processing is left for lmap2.0

   o  add some cautionary words about what if the Collector unexpectedly
      doesn't hear from a MA

   o  add some extra words about the potential impact of Measurement
      Tasks

   o  clarified various aspects of the privacy section

   o  updated references

   o  minor tweaks

11.3.  From -02 to -03

   o  alignment with the Information Model
      [I-D.burbridge-lmap-information-model] as this is agreed as a WG
      document

   o  One-off and periodic Measurement Schedules are kept separate, so
      that they can be updated independently

   o  Measurement Suppression in a separate sub-section.  Can now
      optionally include particular Measurement Tasks &/or Schedules to
      suppress, and start/stop time

   o  for clarity, concept of Channel split into Control, Report and MA-
      to-Controller Channels

   o  numerous editorial changes, mainly arising from a very detailed
      review by Charles Cook

   o

12.  Informative References

   [Bur10]    Burkhart, M., Schatzmann, D., Trammell, B., and E. Boschi,
              "The Role of Network Trace anonymisation Under Attack",
              January 2010.




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   [Q1741]    Q.1741.7, , "IMT-2000 references to Release 9 of GSM-
              evolved UMTS core network",
              http://www.itu.int/rec/T-REC-Q.1741.7/en, November 2011.

   [RFC1035]  Mockapetris, P., "Domain names - implementation and
              specification", STD 13, RFC 1035, November 1987.

   [RFC4101]  Rescorla, E. and IAB, "Writing Protocol Models", RFC 4101,
              June 2005.

   [RFC4122]  Leach, P., Mealling, M., and R. Salz, "A Universally
              Unique IDentifier (UUID) URN Namespace", RFC 4122, July
              2005.

   [RFC5357]  Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
              Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
              RFC 5357, October 2008.

   [I-D.ietf-lmap-use-cases]
              Linsner, M., Eardley, P., Burbridge, T., and F. Sorensen,
              "Large-Scale Broadband Measurement Use Cases", draft-ietf-
              lmap-use-cases-01 (work in progress), December 2013.

   [I-D.bagnulo-ippm-new-registry-independent]
              Bagnulo, M., Burbridge, T., Crawford, S., Eardley, P., and
              A. Morton, "A registry for commonly used metrics.
              Independent registries", draft-bagnulo-ippm-new-registry-
              independent-01 (work in progress), July 2013.

   [I-D.ietf-homenet-arch]
              Chown, T., Arkko, J., Brandt, A., Troan, O., and J. Weil,
              "IPv6 Home Networking Architecture Principles", draft-
              ietf-homenet-arch-11 (work in progress), October 2013.

   [RFC6419]  Wasserman, M. and P. Seite, "Current Practices for
              Multiple-Interface Hosts", RFC 6419, November 2011.

   [RFC6887]  Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P.
              Selkirk, "Port Control Protocol (PCP)", RFC 6887, April
              2013.

   [RFC5533]  Nordmark, E. and M. Bagnulo, "Shim6: Level 3 Multihoming
              Shim Protocol for IPv6", RFC 5533, June 2009.








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   [I-D.burbridge-lmap-information-model]
              Burbridge, T., Eardley, P., Bagnulo, M., and J.
              Schoenwaelder, "Information Model for Large-Scale
              Measurement Platforms (LMAP)", draft-burbridge-lmap-
              information-model-01 (work in progress), October 2013.

   [RFC6235]  Boschi, E. and B. Trammell, "IP Flow Anonymization
              Support", RFC 6235, May 2011.

   [RFC6973]  Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
              Morris, J., Hansen, M., and R. Smith, "Privacy
              Considerations for Internet Protocols", RFC 6973, July
              2013.

   [I-D.ietf-ippm-lmap-path]
              Bagnulo, M., Burbridge, T., Crawford, S., Eardley, P., and
              A. Morton, "A Reference Path and Measurement Points for
              LMAP", draft-ietf-ippm-lmap-path-01 (work in progress),
              September 2013.

Authors' Addresses

   Philip Eardley
   British Telecom
   Adastral Park, Martlesham Heath
   Ipswich
   ENGLAND

   Email: philip.eardley@bt.com


   Al Morton
   AT&T Labs
   200 Laurel Avenue South
   Middletown, NJ
   USA

   Email: acmorton@att.com













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   Marcelo Bagnulo
   Universidad Carlos III de Madrid
   Av. Universidad 30
   Leganes, Madrid  28911
   SPAIN

   Phone: 34 91 6249500
   Email: marcelo@it.uc3m.es
   URI:   http://www.it.uc3m.es


   Trevor Burbridge
   British Telecom
   Adastral Park, Martlesham Heath
   Ipswich
   ENGLAND

   Email: trevor.burbridge@bt.com


   Paul Aitken
   Cisco Systems, Inc.
   96 Commercial Street
   Edinburgh, Scotland  EH6 6LX
   UK

   Email: paitken@cisco.com


   Aamer Akhter
   Cisco Systems, Inc.
   7025 Kit Creek Road
   RTP, NC  27709
   USA

   Email: aakhter@cisco.com















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