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Internet Engineering Task Force                            M. Ersue, Ed.
Internet-Draft                                    Nokia Siemens Networks
Intended status: Informational                         D. Romascanu, Ed.
Expires: August 18, 2013                                           Avaya
                                                   J. Schoenwaelder, Ed.
                                                Jacobs University Bremen
                                                       February 14, 2013


Management of Networks with Constrained Devices: Problem Statement, Use
                         Cases and Requirements
                    draft-ersue-constrained-mgmt-03

Abstract

   This document provides a problem statement and discusses the use
   cases and requirements for the management of networks with
   constrained devices.

Status of this Memo

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   This Internet-Draft will expire on August 18, 2013.

Copyright Notice

   Copyright (c) 2013 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   include Simplified BSD License text as described in Section 4.e of



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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
     1.1.  Overview . . . . . . . . . . . . . . . . . . . . . . . . .  4
     1.2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . .  5
     1.3.  Class of Networks in Focus . . . . . . . . . . . . . . . .  7
     1.4.  Constrained Device Deployment Options  . . . . . . . . . . 10
     1.5.  Management Topology Options  . . . . . . . . . . . . . . . 11
     1.6.  Managing the Constrainedness of a Device or Network  . . . 11
   2.  Problem Statement  . . . . . . . . . . . . . . . . . . . . . . 15
   3.  Use Cases  . . . . . . . . . . . . . . . . . . . . . . . . . . 17
     3.1.  Environmental Monitoring . . . . . . . . . . . . . . . . . 17
     3.2.  Medical Applications . . . . . . . . . . . . . . . . . . . 17
     3.3.  Industrial Applications  . . . . . . . . . . . . . . . . . 18
     3.4.  Home Automation  . . . . . . . . . . . . . . . . . . . . . 19
     3.5.  Building Automation  . . . . . . . . . . . . . . . . . . . 20
     3.6.  Energy Management  . . . . . . . . . . . . . . . . . . . . 22
     3.7.  Transport Applications . . . . . . . . . . . . . . . . . . 23
     3.8.  Infrastructure Monitoring  . . . . . . . . . . . . . . . . 24
     3.9.  Community Network Applications . . . . . . . . . . . . . . 25
     3.10. Mobile Applications  . . . . . . . . . . . . . . . . . . . 27
     3.11. Automated Metering Infrastructure (AMI)  . . . . . . . . . 29
     3.12. MANET Concept of Operations (CONOPS) in Military . . . . . 31
   4.  Requirements on the Management of Networks with
       Constrained Devices  . . . . . . . . . . . . . . . . . . . . . 36
     4.1.  Management Architecture/System . . . . . . . . . . . . . . 36
     4.2.  Management protocols and data model  . . . . . . . . . . . 41
     4.3.  Configuration management . . . . . . . . . . . . . . . . . 44
     4.4.  Monitoring functionality . . . . . . . . . . . . . . . . . 46
     4.5.  Self-management  . . . . . . . . . . . . . . . . . . . . . 51
     4.6.  Security and Access Control  . . . . . . . . . . . . . . . 52
     4.7.  Energy Management  . . . . . . . . . . . . . . . . . . . . 54
     4.8.  SW Distribution  . . . . . . . . . . . . . . . . . . . . . 56
     4.9.  Traffic management . . . . . . . . . . . . . . . . . . . . 56
     4.10. Transport Layer  . . . . . . . . . . . . . . . . . . . . . 57
     4.11. Implementation Requirements  . . . . . . . . . . . . . . . 59
   5.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 61
   6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 62
   7.  Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 63
   8.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 64
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 65
     9.1.  Normative References . . . . . . . . . . . . . . . . . . . 65
     9.2.  Informative References . . . . . . . . . . . . . . . . . . 65
   Appendix A.  Related Development in other Bodies . . . . . . . . . 67



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     A.1.  ETSI TC M2M  . . . . . . . . . . . . . . . . . . . . . . . 67
     A.2.  OASIS  . . . . . . . . . . . . . . . . . . . . . . . . . . 68
     A.3.  OMA  . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
     A.4.  IPSO Alliance  . . . . . . . . . . . . . . . . . . . . . . 69
   Appendix B.  Related Research Projects . . . . . . . . . . . . . . 71
   Appendix C.  Open issues . . . . . . . . . . . . . . . . . . . . . 72
   Appendix D.  Change Log  . . . . . . . . . . . . . . . . . . . . . 73
     D.1.  02-03  . . . . . . . . . . . . . . . . . . . . . . . . . . 73
     D.2.  01-02  . . . . . . . . . . . . . . . . . . . . . . . . . . 74
     D.3.  00-01  . . . . . . . . . . . . . . . . . . . . . . . . . . 74
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 76








































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1.  Introduction

1.1.  Overview

   Small devices with limited CPU, memory, and power resources, so
   called constrained devices (aka. sensor, smart object, or smart
   device) can constitute a network.  Such a network of constrained
   devices itself may be constrained or challenged, e.g. with unreliable
   or lossy channels, wireless technologies with limited bandwidth and a
   dynamic topology, needing the service of a gateway or proxy to
   connect to the Internet.  In other scenarios, the constrained devices
   can be connected to a non-constrained network using off-the-shelf
   protocol stacks.

   Constrained devices might be in charge of gathering information in
   diverse settings including natural ecosystems, buildings, and
   factories and send the information to one or more server stations.
   Constrained devices may work under severe resource constraints such
   as limited battery and computing power, little memory and
   insufficient wireless bandwidth, and communication capabilities.  A
   central entity, e.g., a base station or controlling server, might
   have more computational and communication resources and can act as a
   gateway between the constrained devices and the application logic in
   the core network.

   Today diverse size of small devices with different resources and
   capabilities are becoming connected.  Mobile personal gadgets,
   building-automation devices, cellular phones, Machine-to-machine
   (M2M) devices, etc. benefit from interacting with other "things" in
   the near or somewhere in the Internet.  With this the Internet of
   Things (IoT) becomes a reality build up of uniquely identifiable
   objects (things).  And over the next decade, this could grow to
   trillions of constrained devices and will greatly increase the
   Internet's size and scope.

   Network management is characterized by monitoring network status,
   detecting faults, and inferring their causes, setting network
   parameters, and carrying out actions to remove faults, maintain
   normal operation, and improve network efficiency and application
   performance.  The traditional network management application
   periodically collects information from a set of elements that are
   needed to manage, processes the data, and presents them to the
   network management users.  Constrained devices, however, often have
   limited power, low transmission range, and might be unreliable.  They
   might also need to work in hostile environments with advanced
   security requirements or need to be used in harsh environments for a
   long time without supervision.  Due to such constraints, the
   management of a network with constrained devices offers different



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   type of challenges compared to the management of a traditional IP
   network.

   The IETF has already done a lot of standardization work to enable the
   communication in IP networks and to manage such networks as well as
   the manifold type of nodes in these networks [RFC6632].  However, the
   IETF so far has not developed any specific technologies for the
   management of constrained devices and the networks comprised by
   constrained devices.  IP-based sensors or constrained devices in such
   an environment, i.e., devices with very limited memory and CPU
   resources, use today application-layer protocols in an ad-hoc manner
   to do simple resource management and monitoring.

   This document raises the questions on and aims to understand the use
   cases and requirements for the management of a network with
   constrained devices.  The document especially aims to avoid
   recommending any particular solutions.  Section 1.3 and Section 1.5
   describe different topology options for the networking and management
   of constrained devices.  Section 1.4 explains different deployment
   options for the networking of constrained devices.  Section 2
   provides a problem statement on the issue of the management of
   networked constrained devices.  Section 3 lists diverse use cases and
   scenarios for the management from the network as well as from the
   application point of view.  Section 4 lists requirements on the
   management of applications and networks with constrained devices.
   Note that the requirements in Section 4 need to be seen as standalone
   requirements.  As of today this document does not recommend the
   realization of a profile of requirements.

1.2.  Terminology

   Concerning constrained devices and networks this document generally
   builds on the terminology defined in [LWIG-TERMS].  As such the terms
   like Constrained Device, Constrained Network, etc. are defined in
   [LWIG-TERMS].

   The following terms are additionally used throughout this
   documentation:

   AMI:  (Advanced Metering Infrastructure) A system including hardware,
      software, and networking technologies that measures, collects, and
      analyzes energy usage, and communicates with a hierarchically
      deployed network of metering devices, either on request or on a
      schedule.







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   C0:  Class 0 constrained device as defined in Section 3. of [LWIG-
      TERMS].

   C1:  Class 1 constrained device as defined in Section 3. of [LWIG-
      TERMS].

   C2:  Class 2 constrained device as defined in Section 3. of [LWIG-
      TERMS].

   Client:  The originating endpoint of a request; the destination
      endpoint of a response.

   Intermediary entity:  As defined in the CoAP document an intermediary
      entity can be a CoAP endpoint that acts both as a server and as a
      client towards (possibly via further intermediaries) an origin
      server.  An intermediary entity can be used to support
      hierarchical management.

   Network of Constrained Devices:  A network to which constrained
      devices are connected.  It may or may not be a Constrained Network
      (see [LWIG-TERMS] for the definition of the term Constrained
      Network).

   M2M:  (Machine to Machine) stands for the automatic data transfer
      between devices of different kind.  In M2M scenarios a device
      (such as a sensor or meter) captures an event, which is relayed
      through a network (wireless, wired or hybrid) to an application.

   MANET:  Mobile Ad-hoc Networks, a self-configuring and
      infrastructureless network of mobile devices connected by wireless
      technologies.

   Mote:  A sensor node in a wireless network that is capable of
      performing some limited processing, gathering sensory information
      and communicating with other connected nodes in the network.

   Server:  The destination endpoint of a request; the originating
      endpoint of a response.

   Smart Grid:  An electrical grid that uses communication technologies
      to gather and act on information in an automated fashion to
      improve the efficiency, reliability and sustainability of the
      production and distribution of electricity.

   Smart Meter:  An electrical meter (in the context of a Smart Grid)
      that records consumption of electric energy in intervals of an
      hour or less and communicates that information at least daily back
      to the utility network for monitoring and billing purposes.



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      For a detailed discussion on the constrained networks as well as
      classes of constrained devices and their capabilities please see
      [LWIG-TERMS].

1.3.  Class of Networks in Focus

   In this document we differentiate following type of networks
   concerning their transport and communication technologies:

   (Note that a network in general can involve constrained and non-
   constrained devices.)

   o  Wireline non-constrained networks (CN0), e.g. an Ethernet-LAN with
      non-constrained and constrained devices involved.

   o  A combination of wireline and wireless networks (CN1), which may
      or may not be mesh-based but have a multi-hop connectivity between
      constrained devices, utilizing dynamic routing in both the
      wireless and wireline portions of the network.  CN1 usually
      support highly distributed applications with many nodes (e.g.
      environmental monitoring).  CN1 tend to deal with large-scale
      multipoint-to-point systems with massive data flows.  Wireless
      Mesh Networks (WMN), as a specific type of CN1 networks, use off-
      the-shelf radio technology such as Wi-Fi, WiMax, and cellular
      3G/4G. WMNs are reliable based on the redundancy they offer and
      have often a more planned deployment to provide dynamic and cost
      effective connectivity over a certain geographic area.

   o  A combination of wireline and wireless networks with point-to-
      point or point-to-multipoint communication (CN2) generally with
      single-hop connectivity to constrained devices, utilizing static
      routing over the wireless network.  CN2 support short-range,
      point-to-point, low-data-rate, source-to-sink type of applications
      such as RFID systems, light switches, fire and smoke detectors,
      and home appliances.  CN2 usually support confined short-range
      spaces such as a home, a factory, a building, or the human body.
      IEEE 802.15.1 (Bluetooth) and IEEE 802.15.4 are well-known
      examples of applicable standards for CN2 networks.

   o  Mobile Adhoc networks (MANET) are self-configuring
      _infrastructureless_ networks of mobile devices connected by
      wireless technologies.  MANETs are based on point-to-point
      communications of devices moving independently in any direction
      and changing the links to other devices frequently.  MANET devices
      do act as a router to forward traffic unrelated to their own use.

   A CN0 is used for specific applications like Building Automation or
   Infrastructure Monitoring.  However, CN1 and CN2 networks are



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   especially in the interest of the analysis on the management of
   constrained devices in this document.

   Furthermore different network characteristics are determined by
   multiple dimensions: dynamicity of the topology, bandwidth, and loss
   rate.  In the following, each dimension is explained, and networks in
   scope for this document are outlined:

   Network Topology:

   The topology of a network can be represented as a graph, with edges
   (i.e., links) and vertices (routers and hosts).  Examples of
   different topologies include "star" topologies (with one central node
   and multiple nodes in one hop distance), tree structures (with each
   node having exactly one parent), directed acyclic graphs (with each
   node having one or more parents), clustered topologies (where one or
   more "cluster heads" are responsible for a certain area of the
   network), mesh topologies (fully distributed), etc.

   Management protocols may take advantage of specific network
   topologies, for example by distributing large-scale management tasks
   amongst multiple distributed network management stations (e.g., in
   case of a mesh topology), or by using a hierarchical management
   approach (e.g., in case of a tree topology).  These different
   management topology options are described in Section 1.6.

   Note that in certain network deployments, such as community ad hoc
   networks (as described in Section 3.9, the topology is not pre-
   planned, and thus may be unknown for management purposes.  In other
   use cases, such as industrial applications (as described in
   Section 3.3, the topology may be designed in advance and therefore
   taken advantage of when managing the network.

   Dynamicity of the network topology:

   The dynamicity of the network topology determines the rate of change
   of the graph per time.  Such changes can occur due to different
   factors, such as mobility of nodes (e.g., in MANETs or cellular
   networks), duty cycles (for low-power devices enabling their network
   interface only periodically to transmit or receive packets), or
   unstable links (in particular wireless links with strongly
   fluctuating link quality).

   Examples of different levels of dynamicity of the topology are
   Ethernets (with typically a very static topology) on the one side,
   and low-power and lossy networks (LLNs) on the other side.  LLNs
   nodes often using duty cycles, operate on unreliable wireless links
   and are potentially mobile (e.g. for sensor networks).



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   The more the topology is dynamic, the more routing, transport and
   application layer protocols have to cope with interrupted
   connectivity and/or longer delays.  For example, management protocols
   (with a given underlying transport protocol) that expect continuous
   session flows without changes of routes during a communication flow,
   may fail to operate.

   Networks with a very low dynamicity (e.g.  Ethernet) with no or
   infrequent topology changes (e.g. less than once every 30 minutes),
   are in-scope of this document if they are used with constrained
   devices (see e.g. the use case "Building Automation" in Section 3.5).

   Traffic flows:

   The traffic flow in a network determines from which sources data
   traffic is sent to which destinations in the network.  Several
   different traffic flows are defined in [I-D.ietf-roll-terminology],
   including "point-to-point" (P2P), "multipoint-to-point" (MP2P), and
   "point-to-multipoint" (P2MP) flows as:

   o  P2P: Point To Point.  This refers to traffic exchanged between two
      nodes (regardless of the number of hops between the two nodes).

   o  P2MP: Point-to-Multipoint traffic refers to traffic between one
      node and a set of nodes.  This is similar to the P2MP concept in
      Multicast or MPLS Traffic Engineering.

   o  MP2P: Multipoint-to-Point is used to describe a particular traffic
      pattern (e.g.  MP2P flows collecting information from many nodes
      flowing inwards towards a collecting sink).

   If one of these traffic patterns is predominant in a network,
   protocols (routing, transport, application) may be optimized for the
   specific traffic flow.  For example, in a network with a tree
   topology and MP2P traffic, collection tree protocols are efficient to
   send data from the leaves of the tree to the root of the tree, via
   each node's parent.

   Bandwidth:

   The bandwidth of the network is the amount of data that can be sent
   per time between two communication end-points.  It is usually
   determined by the link with the minimum bandwidth on the path from
   the source to the destination of data packets.  The bandwidth in
   networks can range from a few Kilobytes per second (such as on some
   802.15.4 link layers) to many Gigabytes per second (e.g., on fiber
   optics).




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   For management purposes, the management protocol typically requires
   to send information between the network management station and the
   clients, for monitoring or control purposes.  If the available
   bandwidth is insufficient for the management protocol, packets will
   be buffered and eventually dropped, and thus management is not
   possible with such a protocol.

   Networks without bandwidth limitation (e.g.  Ethernet) are in-scope
   of this document if they are used with constrained devices (see the
   use case "Building Automation" in Section 3.5).

   Loss rate:

   The loss rate (or bit error rate) is the number of bit errors divided
   by the total number of bits transmitted.  For wired networks, loss
   rates are typically extremely low, e.g. around 10^-12 or 10^-13 for
   the latest 10Gbit Ethernet.  For wireless networks, such as 802.15.4,
   the bit error rate can be as high as 10^-1 to 10^-0 in case of
   interferences.Even when using a reliable transport protocol,
   management operations can fail if the loss rate is too high, unless
   they are specifically designed to cope with these situations.

   Note: The discussion on the management requirements of MANETs is
   currently not in the focus of this document.  The use case in
   Section 3.4 has been provided to make it clear how a MANET-based
   application differs from others.

1.4.  Constrained Device Deployment Options

   We differentiate following Deployment options for the constrained
   devices:

   o  a network of constrained devices, which communicate with each
      other,

   o  Constrained devices, which are connected directly to the Internet
      or an IP network

   o  A network of constrained devices which communicate with a gateway
      or proxy with more communication capabilities acting possibly as a
      representative of the device to entities in the non-constrained
      network

   o  Constrained devices, which are connected to the Internet or an IP
      network via a gateway/proxy

   o  A hierarchy of constrained devices, e.g., a network of C0 devices
      connected to one or more C1 devices - connected to one or more C2



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      devices - connected to one or more gateways - connected to some
      application servers or NMS system

   o  The possibility of device grouping (possibly in a dynamic manner)
      such as that the grouped devices can act as one logical device at
      the edge of the network and one device in this group can act as
      the managing entity

1.5.  Management Topology Options

   We differentiate following options for the management of networks of
   constrained devices:

   o  A network of constrained devices managed by one central manager.
      A logically centralized management might be implemented in a
      hierarchical fashion for scalability and robustness reasons.  The
      manager and the management application logic might have a gateway/
      proxy in between or might be on different nodes in different
      networks, e.g., management application running on a cloud server.

   o  Distributed management, where a constrained network is managed by
      more than one manager.  Each manager controls a subnetwork and may
      communicate directly with other manager stations in a cooperative
      fashion.  The distributed management may be weakly distributed,
      where functions are broken down and assigned to many managers
      dynamically, or strongly distributed, where almost all managed
      things have embedded management functionality and explicit
      management disappears, which usually comes with the price that the
      strongly distributed management logic now needs to be managed.

   o  Hierarchical management, where a hierarchy of constrained networks
      are managed by the managers at their corresponding hierarchy
      level.  I.e. each manager is responsible for managing the nodes in
      its sub-network.  It passes information from its sub-network to
      its higher-level manager, and disseminates management functions
      received from the higher-level manager to its sub-network.
      Hierarchical management is essentially a scalability mechanism,
      logically the decision-making may be still centralized.

1.6.  Managing the Constrainedness of a Device or Network

   The capabilities of a constrained device or network and the
   constrainedness thereof influence and have an impact on the
   requirements for the management of such network or devices.

   A constrained device:





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   o  might only support an unreliable radio with lossy links, i.e. the
      client and server of a management protocol need to gracefully
      ignore incomplete commands or repeat commands as necessary.

   o  might only be able to go online from time-to-time, where it is
      reachable, i.e. a command might be necessary to repeat after a
      longer timeout or the timeout value with which one endpoint waits
      on a response needs to be sufficiently high.

   o  might only be able to support a limited operating time (e.g. based
      on the available battery), i.e. the devices need to economize
      their energy usage with suitable mechanisms and the managing
      entity needs to monitor and control the energy status of the
      constrained devices it manages.

   o  might only be able to support one simple communication protocol,
      i.e. the management protocol needs to be possible to downscale
      from constrained (C2) to very constrained (C0) devices with
      modular implementation and a very basic version with just a few
      simple commands.

   o  might only be able to support limited or no user and/or transport
      security, i.e. the management system needs to support a less-
      costly and simple but sufficiently secure authentication
      mechanism.

   o  might not be able to support compression and decompression of
      exchanged data based on limited CPU power, i.e. an intermediary
      entity which is capable of data compression should be able to
      communicate with both, devices, which support data compression
      (e.g.  C2) and devices, which do not support data compression
      (e.g.  C1 and C0).

   o  might only be able to support very simple encryption, i.e. it
      would be efficient if the devices use cryptographic algorithms
      that are supported in hardware.

   o  might only be able to communicate with one single managing entity
      and cannot support the parallel access of many managing entities.

   o  might depend on a self-configuration feature, i.e. the managing
      entity might not know all devices in a network and the device
      needs to be able to initiate connection setup for the device
      configuration.

   o  might depend on self- or neighbor-monitoring feature, i.e. the
      managing entity might not be able to monitor all devices in a
      network continuously.



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   o  might only be able to communicate with its neighbors, i.e. the
      device should be able to get its configuration from a neighbor.

   o  might only be able to support parsing of data models with limited
      size, i.e. the device data models need to be compact containing
      the most necessary data and if possible parsable as a stream.

   o  might only be able to support a limited or no failure detection,
      i.e. the managing entity needs to handle the situation, where a
      failure does not get detected or gets detected late gracefully
      e.g. with asking repeatedly.

   o  might only be able to support the reporting of just one or a
      limited set failure types.

   o  might only be able to support a limited set of notifications,
      possible only an "I-am-alive" message.

   o  might only be able to support a soft-reset from failure recovery.

   o  might possibly generate a huge amount of redundant reporting data,
      i.e. the intermediary management entity should be able to filter
      and aggregate redundant data.

   A constrained network:

   o  might only support an unreliable radio with lossy links, i.e. the
      client and server of a management protocol need to repeat commands
      as necessary or gracefully ignore incomplete commands.

   o  might be necessary to manage based on multicast communication,
      i.e. the managing entity needs to be prepared to configure many
      devices at once based on the same data model.

   o  might have a very large topology supporting 10.000 or more nodes
      for some applications and as such node naming is a specific issue
      for constrained networks.

   o  must be able to self-organize, i.e. given the large number of
      nodes and their potential placement in hostile locations and
      frequently changing topology, manual configuration is typically
      not feasible.  As such the network must be able to reconfigure
      itself so that it can continue to operate properly and support
      reliable connectivity.

   o  needs a management solution, which is energy-efficient, using as
      little wireless bandwidth as possible since communication is
      highly energy demanding.



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   o  needs to support localization schemes to determine the location of
      devices since the devices might be moving and location information
      is important for some applications.

   o  needs a management solution, which is scalable as the network may
      consist of thousands of nodes and may need to be extended
      continuously.

   o  needs to provide fault tolerance.  Faults in network operation
      including hardware and software errors, failures detected by the
      transport protocol and other self-monitoring mechanisms can be
      used to provide fault tolerance.

   o  might require new management capabilities: for example, network
      coverage information and a constrained device power-distribution-
      map.

   o  might require a new management function for data management, since
      the type and amount of data collected in constrained networks is
      different from those of the traditional networks.

   o  might also need energy-efficient key management algorithms for
      security.




























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2.  Problem Statement

   The terminology for the "Internet of Things" is still nascent, and
   depending on the network type or layer in focus diverse technologies
   and terms are in use.  Common to all these considerations is the
   "Things" or "Objects" are supposed to have physical or virtual
   identities using interfaces to communicate.  In this context, we need
   to differentiate between the Constrained and Smart Devices identified
   by an IP address compared to virtual entities such as Smart Objects,
   which can be identified as a resource or a virtual object by using a
   unique identifier.  Furthermore, the smart devices usually have a
   limited memory and CPU power as well as aim to be self-configuring
   and easy to deploy.

   However, the tininess of the network nodes requires a rethinking of
   the protocol characteristics concerning power consumption,
   performance, memory, and CPU usage.  As such, there is a demand for
   protocol simplification, energy-efficient communication, less CPU
   usage and small memory footprint.

   On the application layer the IETF is already developing protocols
   like the Constrained Application Protocol (CoAP) [I-D.ietf-core-coap]
   supporting constrained devices and networks e.g., for smart energy
   applications or home automation environments.  The deployment of such
   an environment involves in fact many, in some scenarios up to million
   small devices (e.g. smart meters), which produce a huge amount of
   data.  This data needs to be collected, filtered, and pre-processed
   for further use in diverse services.

   Considering the high number of nodes to deploy, one has to think on
   the manageability aspects of the smart devices and plan for easy
   deployment, configuration, and management of the networks of
   constrained devices as well as the devices themselves.  Consequently,
   seamless monitoring and self-configuration of such network nodes
   becomes more and more imperative.  Self-configuration and self-
   management is already a reality in the standards of some of the
   bodies such as 3GPP.  To introduce self-configuration of smart
   devices successfully a device-initiated connection establishment is
   required.

   A simple application layer protocol, such as CoAP, is essential to
   address the issue of efficient object-to-object communication and
   information exchange.  Such an information exchange should be done
   based on interoperable data models to enable the exchange and
   interpretation of diverse application and management related data.

   In an ideal world, we would have only one network management protocol
   for monitoring, configuration, and exchanging management data,



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   independently of the type of the network (e.g., Smart Grid, wireless
   access, or core network).  Furthermore, it would be desirable to
   derive the basic data models for constrained devices from the core
   models used today to enable reuse of functionality and end-to-end
   information exchange.  However, the current management protocols seem
   to be too heavyweight compared to the capabilities the constrained
   devices have and are not applicable directly for the use in a network
   of constrained devices.  Furthermore, the data models addressing the
   requirements of such smart devices need yet to be designed.

   The IETF so far has not developed any specific technologies for the
   management of constrained devices and the networks comprised by
   constrained devices.  IP-based sensors or constrained devices in such
   an environment, i.e., devices with very limited memory and CPU
   resources, use today, e.g., application-layer protocols to do simple
   resource management and monitoring.  This might be sufficient for
   some basic cases, however, there is a need to reconsider the network
   management mechanisms based on the new, changed, as well as reduced
   requirements coming from smart devices and the network of such
   constrained devices.  Albeit it is questionable whether we can take
   the same comprehensive approach we use in an IP network also for the
   management of constrained devices.  Hence, the management of a
   network with constrained devices might become necessary to design as
   much as possible simplified and less complex.

   As the Section 1.6 highlights, there are diverse characterists of
   constrained devices or networks, which stem from their constraindness
   and therefor have an impact on the requirements for the management of
   such a network with constrained devices.  The use cases discussed in
   Section 3 show that the requirements on constrained networks are
   manifold and need to be analyzed from different angles, e.g.
   concerning the design of the management architecture, the selection
   of the appropriate protocol features as well as the specific issues
   which are new in the context of constrained devices.  Examples of
   such issues are e.g. the careful management of the scarce energy
   resources, the necessity for self-organization and self-management of
   such devices but also the implementation considerations to enable the
   use of common communication technologies on a constrained hardware in
   an efficient manner.  For an exhaustive list of issues and
   requirements, which need to be addressed for the management of a
   network with constrained devices please see Section 1.6 and
   Section 4.









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3.  Use Cases

   This section discusses some application scenarios where networks of
   constrained devices are expected to be deployed.  For each
   application scenario, we first briefly describe the characteristics
   followed by a discussion how network management can be provided, who
   is likely going to be responsible for it, and on which time-scale
   management operations are likely to be carried out.

3.1.  Environmental Monitoring

   Environmental monitoring applications are characterized by the
   deployment of a number of sensors to monitor emissions, water
   quality, or even the movements and habits of wildlife.  Other
   applications in this category include earthquake or tsunami early-
   warning systems.  The sensors often span a large geographic area,
   they can be mobile, and they are often difficult to replace.
   Furthermore, the sensors are usually not protected against tampering.

   Management of environmental monitoring applications is largely
   concerned with the monitoring whether the system is still functional
   and the roll-out of new constrained devices in case the system looses
   too much of its structure.  The constrained devices themselves need
   to be able to establish connectivity (auto-configuration) and they
   need to be able to deal with events such as loosing neighbors or
   being moved to other locations.

   Management responsibility typically rests with the organization
   running the environmental monitoring application.  Since these
   monitoring applications must be designed to tolerate a number of
   failures, the time scale for detecting and recording failures is for
   some of these applications likely measured in hours and repairs might
   easily take days.  However, for certain environmental monitoring
   applications, much tighter time scales may exist and might be
   enforced by regulations (e.g., monitoring of nuclear radiation).

3.2.  Medical Applications

   Constrained devices can be seen as an enabling technology for
   advanced and possibly remote health monitoring and emergency
   notification systems, ranging from blood pressure and heart rate
   monitors to advanced devices capable to monitor implanted
   technologies, such as pacemakers or advanced hearing aids.  Medical
   sensors may not only be attached to human bodies, they might also
   exist in the infrastructure used by humans such as bathrooms or
   kitchens.  Medical applications will also be used to ensure
   treatments are being applied properly and they might guide people
   losing orientation.  Fitness and wellness applications, such as



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   connected scales or wearable heart monitors, encourage consumers to
   exercise and empower self-monitoring of key fitness indicators.
   Different applications use Bluetooth, Wi-Fi or Zigbee connections to
   access the patient's smartphone or home cellular connection to access
   the Internet.

   Constrained devices that are part of medical applications are managed
   either by the users of those devices or by an organization providing
   medical (monitoring) services for physicians.  In the first case,
   management must be automatic and or easy to install and setup by
   average people.  In the second case, it can be expected that devices
   be controlled by specially trained people.  In both cases, however,
   it is crucial to protect the privacy of the people to which medical
   devices are attached.  Even though the data collected by a heart beat
   monitor might be protected, the pure fact that someone carries such a
   device may need protection.  As such, certain medical appliances may
   not want to participate in discovery and self-configuration protocols
   in order to remain invisible.

   Many medical devices are likely to be used (and relied upon) to
   provide data to physicians in critical situations since the biggest
   market is likely elderly and handicapped people.  As such, fault
   detection of the communication network or the constrained devices
   becomes a crucial function that must be carried out with high
   reliability and, depending on the medical appliance and its
   application, within seconds.

3.3.  Industrial Applications

   Industrial Applications and smart manufacturing refer not only to
   production equipment, but also to a factory that carries out
   centralized control of energy, HVAC (heating, ventilation, and air
   conditioning), lighting, access control, etc. via a network.  For the
   management of a factory it is becoming essential to implement smart
   capabilities.  From an engineering standpoint, industrial
   applications are intelligent systems enabling rapid manufacturing of
   new products, dynamic response to product demand, and real-time
   optimization of manufacturing production and supply chain networks.
   Potential industrial applications e.g. for smart factories and smart
   manufacturing are:

   o  Digital control systems with embedded, automated process controls,
      operator tools, as well as service information systems optimizing
      plant operations and safety.

   o  Asset management using predictive maintenance tools, statistical
      evaluation, and measurements maximizing plant reliability.




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   o  Smart sensors detecting anomalies to avoid abnormal or
      catastrophic events.

   o  Smart systems integrated within the industrial energy management
      system and externally with the smart grid enabling real-time
      energy optimization.

   Sensor networks are an essential technology used for smart
   manufacturing.  Measurements, automated controls, plant optimization,
   health and safety management, and other functions are provided by a
   large number of networked sectors.  Data interoperability and
   seamless exchange of product, process, and project data are enabled
   through interoperable data systems used by collaborating divisions or
   business systems.  Intelligent automation and learning systems are
   vital to smart manufacturing but must be effectively integrated with
   the decision environment.  Wireless sensor networks (WSN) have been
   developed for machinery Condition-based Maintenance (CBM) as they
   offer significant cost savings and enable new functionalities.
   Inaccessible locations, rotating machinery, hazardous areas, and
   mobile assets can be reached with wireless sensors.  WSNs can provide
   today wireless link reliability, real-time capabilities, and quality-
   of-service and enable industrial and related wireless sense and
   control applications.

   Management of industrial and factory applications is largely focused
   on the monitoring whether the system is still functional, real-time
   continuous performance monitoring, and optimization as necessary.
   The factory network might be part of a campus network or connected to
   the Internet.  The constrained devices in such a network need to be
   able to establish configuration themselves (auto-configuration) and
   might need to deal with error conditions as much as possible locally.
   Access control has to be provided with multi-level administrative
   access and security.  Support and diagnostics can be provided through
   remote monitoring access centralized outside of the factory.

   Management responsibility is typically owned by the organization
   running the industrial application.  Since the monitoring
   applications must handle a potentially large number of failures, the
   time scale for detecting and recording failures is for some of these
   applications likely measured in minutes.  However, for certain
   industrial applications, much tighter time scales may exist, e.g. in
   real-time, which might be enforced by the manufacturing process or
   the use of critical material.

3.4.  Home Automation

   Home automation includes the control of lighting, heating,
   ventilation, air conditioning, appliances, and entertainment devices



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   to improve convenience, comfort, energy efficiency, and security.  It
   can be seen as a residential extension of building automation.

   Home automation networks need a certain amount of configuration
   (associating switches or sensors to actors) that is either provided
   by electricians deploying home automation solutions or done by
   residents by using the application user interface to configure (parts
   of) the home automation solution.  Similarly, failures may be
   reported via suitable interfaces to residents or they might be
   recorded and made available to electricians in charge of the
   maintenance of the home automation infrastructure.

   The management responsibility lies either with the residents or it
   may be outsourced to electricians providing management of home
   automation solutions as a service.  The time scale for failure
   detection and resolution is in many cases likely counted in hours to
   days.

3.5.  Building Automation

   Building automation comprises the distributed systems designed and
   deployed to monitor and control the mechanical, electrical and
   electronic systems inside buildings with various destinations (e.g.,
   public and private, industrial, institutions, or residential).
   Advanced Building Automation Systems (BAS) may be deployed
   concentrating the various functions of safety, environmental control,
   occupancy, security.  More and more the deployment of the various
   functional systems is connected to the same communication
   infrastructure (possibly Internet Protocol based), which may involve
   wired or wireless communications networks inside the building.

   Building automation requires the deployment of a large number (10-
   100.000) of sensors that monitor the status of devices, and
   parameters inside the building and controllers with different
   specialized functionality for areas within the building or the
   totality of the building.  Inter-node distances between neighboring
   nodes vary between 1 to 20 meters.  Contrary to home automation in
   building management all devices are known to a set of commissioning
   tools and a data storage, such that every connected device has a
   known origin.  The management includes verifying the presence of the
   expected devices and detecting the presence of unwanted devices.

   Examples of functions performed by such controllers are regulating
   the quality, humidity, and temperature of the air inside the building
   and lighting.  Other systems may report the status of the machinery
   inside the building like elevators, or inside the rooms like
   projectors in meeting rooms.  Security cameras and sensors may be
   deployed and operated on separate dedicated infrastructures connected



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   to the common backbone.  The deployment area of a BAS is typically
   inside one building (or part of it) or several buildings
   geographically grouped in a campus.  A building network can be
   composed of subnets, where a subnet covers a floor, an area on the
   floor, or a given functionality (e.g. security cameras).

   Some of the sensors in Building Automation Systems (for example fire
   alarms or security systems) register, record and transfer critical
   alarm information and therefore must be resilient to events like loss
   of power or security attacks.  This leads to the need that some
   components and subsystems operate in constrained conditions and are
   separately certified.  Also in some environments, the malfunctioning
   of a control system (like temperature control) needs to be reported
   in the shortest possible time.  Complex control systems can
   misbehave, and their critical status reporting and safety algorithms
   need to be basic and robust and perform even in critical conditions.

   Building Automation solutions are deployed in some cases in newly
   designed buildings, in other cases it might be over existing
   infrastructures.  In the first case, there is a broader range of
   possible solutions, which can be planned for the infrastructure of
   the building.  In the second case the solution needs to be deployed
   over an existing structure taking into account factors like existing
   wiring, distance limitations, the propagation of radio signals over
   walls and floors.  As a result, some of the existing WLAN solutions
   (e.g.  IEEE 802.11 or IEEE 802.15) may be deployed.  In mission-
   critical or security sensitive environments and in cases where link
   failures happen often, topologies that allow for reconfiguration of
   the network and connection continuity may be required.  Some of the
   sensors deployed in building automation may be very simple
   constrained devices for which class 0 or class 1 may be assumed.

   For lighting applications, groups of lights must be defined and
   managed.  Commands to a group of light must arrive within 200 ms at
   all destinations.  The installation and operation of a building
   network has different requirements.  During the installation, many
   stand-alone networks of a few to 100 nodes co-exist without a
   connection to the backbone.  During this phase, the nodes are
   identified with a network identifier related to their physical
   location.  Devices are accessed from an installation tool to connect
   them to the network in a secure fashion.  During installation, the
   setting of parameters to common values to enable interoperability may
   occur (e.g.  Trickle parameter values).  During operation, the
   networks are connected to the backbone while maintaining the network
   identifier to physical location relation.  Network parameters like
   address and name are stored in DNS.  The names can assist in
   determining the physical location of the device.




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3.6.  Energy Management

   EMAN working group developed [I-D.ietf-eman-framework], which defines
   a framework for providing Energy Management for devices within or
   connected to communication networks.  This document observes that one
   of the challenges of energy management is that a power distribution
   network is responsible for the supply of energy to various devices
   and components, while a separate communication network is typically
   used to monitor and control the power distribution network.  Devices
   that have energy management capability are defined as Energy Devices
   and identified components within a device (Energy Device Components)
   can be monitored for parameters like Power, Energy, Demand and Power
   Quality.  If a device contains batteries, they can be also monitored
   and managed.

   Energy devices differ in complexity and may include basic sensors or
   switches, specialized electrical meters, or power distribution units
   (PDU), and subsystems inside the network devices (routers, network
   switches) or home or industrial appliances.  An Energy Management
   System is a combination of hardware and software used to administer a
   network with the primary purpose being Energy Management.  The
   operators of such a system are either the utility providers or
   customers that aim to control and reduce the energy consumption and
   the associated costs.  The topology in use differs and the deployment
   can cover areas from small surfaces (individual homes) to large
   geographical areas.  EMAN requirements document
   [I-D.ietf-eman-requirements] discusses the requirements for energy
   management concerning monitoring and control functions.

   It is assumed that Energy Management will apply to a large range of
   devices of all classes and networks topologies.  Specific resource
   monitoring like battery utilization and availability may be specific
   to devices with lower physical resources (device classes C0 or C1).

   Energy Management is especially relevant to Smart Grid.  A Smart Grid
   is an electrical grid that uses data networks to gather and act on
   energy and power-related information, in an automated fashion with
   the goal to improve the efficiency, reliability, economics, and
   sustainability of the production and distribution of electricity.  As
   such Smart Grid provides sustainable and reliable generation,
   transmission, distribution, storage and consumption of electrical
   energy based on advanced energy and ICT solutions and as such enables
   e.g. following specific application areas: Smart transmission
   systems, Demand Response/Load Management, Substation Automation,
   Advanced Distribution Management, Advanced Metering Infrastructure
   (AMI), Smart Metering, Smart Home and Building Automation,
   E-mobility, etc.




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   Smart Metering is a good example of a M2M application and can be
   realized as one of the vertical applications in an M2M environment.
   Different types of possibly wireless small meters produce all
   together a huge amount of data, which is collected by a central
   entity and processed by an application server.  The M2M
   infrastructure can be provided by a mobile network operator as the
   meters in urban areas will have most likely a cellular or WiMAX
   radio.

   Smart Grid is built on a distributed and heterogeneous network and
   can use a combination of diverse networking technologies, such as
   wireless Access Technologies (WiMAX, Cellular, etc.), wireline and
   Internet Technologies (e.g., IP/MPLS, Ethernet, SDH/PDH over Fiber
   optic, etc.) as well as low-power radio technologies enabling the
   networking of smart meters, home appliances, and constrained devices
   (e.g.  BT-LE, ZigBee, Z-Wave, Wi-Fi, etc.).  The operational
   effectiveness of the smart grid is highly dependent on a robust, two-
   way, secure, and reliable communications network with suitable
   availability.

   The management of a distributed system like smart grid requires an
   end-to-end management of and information exchange through different
   type of networks.  However, as of today there is no integrated smart
   grid management approach and no common smart grid information model
   available.  Specific smart grid applications or network islands use
   their own management mechanisms.  For example, the management of
   smart meters depends very much on the AMI environment they have been
   integrated to and the networking technologies they are using.  In
   general, smart meters do only need seldom reconfiguration and they
   send a small amount of redundant data to a central entity.  For a
   discussion on the management needs of an AMI network see
   Section 3.11.  The management needs for Smart Home and Building
   Automation are discussed in Section 3.4 and Section 3.5.

3.7.  Transport Applications

   Transport Application is a generic term for the integrated
   application of communications, control, and information processing in
   a transportation system.  Transport telematics or vehicle telematics
   are used as a term for the group of technologies that support
   transportation systems.  Transport applications running on such a
   transportation system cover all modes of the transport and consider
   all elements of the transportation system, i.e. the vehicle, the
   infrastructure, and the driver or user, interacting together
   dynamically.  The overall aim is to improve decision making, often in
   real time, by transport network controllers and other users, thereby
   improving the operation of the entire transport system.  As such,
   transport applications can be seen as one of the important M2M



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   service scenarios with the involvement of manifold small devices.

   The definition encompasses a broad array of techniques and approaches
   that may be achieved through stand-alone technological applications
   or as enhancements to other transportation communication schemes.
   Examples for transport applications are inter and intra vehicular
   communication, smart traffic control, smart parking, electronic toll
   collection systems, logistic and fleet management, vehicle control,
   and safety and road assistance.

   As a distributed system, transport applications require an end-to-end
   management of different types of networks.  It is likely that
   constrained devices in a network (e.g. a moving in-car network) have
   to be controlled by an application running on an application server
   in the network of a service provider.  Such a highly distributed
   network including mobile devices on vehicles is assumed to include a
   wireless access network using diverse long distance wireless
   technologies such as WiMAX, 3G/LTE or satellite communication, e.g.
   based on an embedded hardware module.  As a result, the management of
   constrained devices in the transport system might be necessary to
   plan top-down and might need to use data models obliged from and
   defined on the application layer.  The assumed device classes in use
   are mainly C2 devices.  In cases, where an in-vehicle network is
   involved, C1 devices with limited capabilities and a short-distance
   constrained radio network, e.g.  IEEE 802.15.4 might be used
   additionally.

   Management responsibility typically rests within the organization
   running the transport application.  The constrained devices in a
   moving transport network might be initially configured in a factory
   and a reconfiguration might be needed only rarely.  New devices might
   be integrated in an ad-hoc manner based on self-management and
   -configuration capabilities.  Monitoring and data exchange might be
   necessary to do via a gateway entity connected to the back-end
   transport infrastructure.  The devices and entities in the transport
   infrastructure need to be monitored more frequently and can be able
   to communicate with a higher data rate.  The connectivity of such
   entities does not necessarily need to be wireless.  The time scale
   for detecting and recording failures in a moving transport network is
   likely measured in hours and repairs might easily take days.  It is
   likely that a self-healing feature would be used locally.

3.8.  Infrastructure Monitoring

   Infrastructure monitoring is concerned with the monitoring of
   infrastructures such as bridges, railway tracks, or (offshore)
   windmills.  The primary goal is usually to detect any events or
   changes of the structural conditions that can impact the risk and



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   safety of the infrastructure being monitored.  Another secondary goal
   is to schedule repair and maintenance activities in a cost effective
   manner.

   The infrastructure to monitor might be in a factory or spread over a
   wider area but difficult to access.  As such, the network in use
   might be based on a combination of fixed and wireless technologies,
   which use robust networking equipment and support reliable
   communication.  It is likely that constrained devices in such a
   network are mainly C2 devices and have to be controlled centrally by
   an application running on a server.  In case such a distributed
   network is widely spread, the wireless devices might use diverse
   long-distance wireless technologies such as WiMAX, or 3G/LTE, e.g.
   based on embedded hardware modules.  In cases, where an in-building
   network is involved, the network can be based on Ethernet or wireless
   technologies suitable for in-building usage.

   The management of infrastructure monitoring applications is primarily
   concerned with the monitoring of the functioning of the system.
   Infrastructure monitoring devices are typically rolled out and
   installed by dedicated experts and changes are rare since the
   infrastructure itself changes rarely.  However, monitoring devices
   are often deployed in unsupervised environments and hence special
   attention must be given to protecting the devices from being
   modified.

   Management responsibility typically rests with the organization
   owning the infrastructure or responsible for its operation.  The time
   scale for detecting and recording failures is likely measured in
   hours and repairs might easily take days.  However, certain events
   (e.g., natural disasters) may require that status information be
   obtained much more quickly and that replacements of failed sensors
   can be rolled out quickly (or redundant sensors are activated
   quickly).  In case the devices are difficult to access, a self-
   healing feature on the device might become necessary.

3.9.  Community Network Applications

   Community networks are comprised of constrained routers in a multi-
   hop mesh topology, communicating over a lossy, and often wireless
   channel.  While the routers are mostly non-mobile, the topology may
   be very dynamic because of fluctuations in link quality of the
   (wireless) channel caused by, e.g., obstacles, or other nearby radio
   transmissions.  Depending on the routers that are used in the
   community network, the resources of the routers (memory, CPU) may be
   more or less constrained - available resources may range from only a
   few kilobytes of RAM to several megabytes or more, and CPUs may be
   small and embedded, or more powerful general-purpose processors.



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   Examples of such community networks are the FunkFeuer network
   (Vienna, Austria), FreiFunk (Berlin, Germany), Seattle Wireless
   (Seattle, USA), and AWMN (Athens, Greece).  These community networks
   are public and non-regulated, allowing their users to connect to each
   other and - through an uplink to an ISP - to the Internet.  No fee,
   other than the initial purchase of a wireless router, is charged for
   these services.  Applications of these community networks can be
   diverse, e.g., location based services, free Internet access, file
   sharing between users, distributed chat services, social networking
   etc, video sharing etc.

   As an example of a community network, the FunkFeuer network comprises
   several hundred routers, many of which have several radio interfaces
   (with omnidirectional and some directed antennas).  The routers of
   the network are small-sized wireless routers, such as the Linksys
   WRT54GL, available in 2011 for less than 50 Euros.  These routers,
   with 16 MB of RAM and 264 MHz of CPU power, are mounted on the
   rooftops of the users.  When new users want to connect to the
   network, they acquire a wireless router, install the appropriate
   firmware and routing protocol, and mount the router on the rooftop.
   IP addresses for the router are assigned manually from a list of
   addresses (because of the lack of autoconfiguration standards for
   mesh networks in the IETF).

   While the routers are non-mobile, fluctuations in link quality
   require an ad hoc routing protocol that allows for quick convergence
   to reflect the effective topology of the network (such as NHDP
   [RFC6130] and OLSRv2 [I-D.ietf-manet-olsrv2] developed in the MANET
   WG).  Usually, no human interaction is required for these protocols,
   as all variable parameters required by the routing protocol are
   either negotiated in the control traffic exchange, or are only of
   local importance to each router (i.e. do not influence
   interoperability).  However, external management and monitoring of an
   ad hoc routing protocol may be desirable to optimize parameters of
   the routing protocol.  Such an optimization may lead to a more stable
   perceived topology and to a lower control traffic overhead, and
   therefore to a higher delivery success ratio of data packets, a lower
   end-to-end delay, and less unnecessary bandwidth and energy usage.

   Different use cases for the management of community networks are
   possible:

   o  One single Network Management Station (NMS), e.g. a border gateway
      providing connectivity to the Internet, requires managing or
      monitoring routers in the community network, in order to
      investigate problems (monitoring) or to improve performance by
      changing parameters (managing).  As the topology of the network is
      dynamic, constant connectivity of each router towards the



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      management station cannot be guaranteed.  Current network
      management protocols, such as SNMP and Netconf, may be used (e.g.,
      using interfaces such as the NHDP-MIB [RFC6779]).  However, when
      routers in the community network are constrained, existing
      protocols may require too many resources in terms of memory and
      CPU; and more importantly, the bandwidth requirements may exceed
      the available channel capacity in wireless mesh networks.
      Moreover, management and monitoring may be unfeasible if the
      connection between the NMS and the routers is frequently
      interrupted.

   o  A distributed network monitoring, in which more than one
      management station monitors or manages other routers.  Because
      connectivity to a server cannot be guaranteed at all times, a
      distributed approach may provide a higher reliability, at the cost
      of increased complexity.  Currently, no IETF standard exists for
      distributed monitoring and management.

   o  Monitoring and management of a whole network or a group of
      routers.  Monitoring the performance of a community network may
      require more information than what can be acquired from a single
      router using a network management protocol.  Statistics, such as
      topology changes over time, data throughput along certain routing
      paths, congestion etc., are of interest for a group of routers (or
      the routing domain) as a whole.  As of 2012, no IETF standard
      allows for monitoring or managing whole networks, instead of
      single routers.

3.10.  Mobile Applications

   M2M services are increasingly provided by mobile service providers as
   numerous devices, home appliances, utility meters, cars, video
   surveillance cameras, and health monitors, are connected with mobile
   broadband technologies.  This diverse range of machines brings new
   network and service requirements and challenges.  Different
   applications e.g. in a home appliance or in-car network use
   Bluetooth, Wi-Fi or Zigbee and connect to a cellular module acting as
   a gateway between the constrained environment and the mobile cellular
   network.

   Such a gateway might provide different options for the connectivity
   of mobile networks and constrained devices, e.g.:

   o  a smart phone with 3G/4G and WLAN radio might use BT-LE to connect
      to the devices in a home area network,

   o  a femtocell might be combined with home gateway functionality
      acting as a low-power cellular base station connecting smart



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      devices to the application server of a mobile service provider.

   o  an embedded cellular module with LTE radio connecting the devices
      in the car network with the server running the telematics service,

   o  an M2M gateway connected to the mobile operator network supporting
      diverse IoT connectivity technologies including ZigBee and CoAP
      over 6LoWPAN over IEEE 802.15.4.

   Common to all scenarios above is that they are embedded in a service
   and connected to a network provided by a mobile service provider.
   Usually there is a hierarchical deployment and management topology in
   place where different parts of the network are managed by different
   management entities and the count of devices to manage is high (e.g.
   many thousands).  In general, the network is comprised by manifold
   type and size of devices matching to different device classes.  As
   such, the managing entity needs to be prepared to manage devices with
   diverse capabilities using different communication or management
   protocols.  In case the devices are directly connected to a gateway
   they most likely are managed by a management entity integrated with
   the gateway, which itself is part of the Network Management System
   (NMS) run by the mobile operator.  Smart phones or embedded modules
   connected to a gateway might be themselves in charge to manage the
   devices on their level.  The initial and subsequent configuration of
   such a device is mainly based on self-configuration and is triggered
   by the device itself.

   The challenges in the management of devices in a mobile application
   are manifold.  Firstly, the issues caused through the device mobility
   need to be taken into consideration.  While the cellular devices are
   moving around or roaming between different regional networks, they
   should report their status to the corresponding management entities
   with regard to their proximity and management hierarchy.  Secondly, a
   variety of device troubleshooting information needs to be reported to
   the management system in order to provide accurate service to the
   customer.  Third but not least, the NMS and the used management
   protocol need to be tailored to keep the cellular devices lightweight
   and as energy efficient as possible.

   The data models used in these scenario are mostly derived from the
   models of the operator NMS and might be used to monitor the status of
   the devices and to exchange the data sent by or read from the
   devices.  The gateway might be in charge of filtering and aggregating
   the data received from the device as the information sent by the
   device might be mostly redundant.






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3.11.  Automated Metering Infrastructure (AMI)

   An AMI network enables an electric utility to retrieve frequent
   electric usage data from each electric meter installed at a
   customer's home or business.  With an AMI network, a utility can also
   receive immediate notification of power outages when they occur,
   directly from the electric meters that are experiencing those
   outages.  In addition, if the AMI network is designed to be open and
   extensible, it could serve as the backbone for communicating with
   other distribution automation devices besides meters, which could
   include transformers and reclosers.

   In this use case, each meter in the AMI network contains a
   constrained device.  These devices are typically C2 devices.  Each
   meter connects to a constrained mesh network with a low-bandwidth
   radio.  These radios can be 50, 150, or 200 kbps at raw link speed,
   but actual network throughput may be significantly lower due to
   forward error correction, multihop delays, MAC delays, lossy links,
   and protocol overhead.

   The constrained devices are used to connect the metering logic with
   the network, so that usage data and outage notifications can be sent
   back to the utility's headend systems over the network.  These
   headend systems are located in a data center managed by the utility,
   and may include meter data collection systems, meter data management
   systems, and outage management systems.

   The meters are connected to a mesh network, and each meter can act as
   both a source of traffic and as a router for other meters' traffic.
   In a typical AMI application, smaller amounts of traffic (read
   requests, configuration) flow "downstream" from the headend to the
   mesh, and larger amounts of traffic flow "upstream" from the mesh to
   the headend.  However, during a firmware update operation, larger
   amounts of traffic might flow downstream while smaller amounts flow
   upstream.  Other applications that make use of the AMI network may
   have their own distinct traffic flows.

   The mesh network is anchored by a collection of higher-end devices,
   which contain a mesh radio that connects to the constrained network
   as well as a backhaul link that connects to a less-constrained
   network.  The backhaul link could be cellular, WiMAX, or Ethernet,
   depending on the backhaul networking technology that the utility has
   chosen.  These higher-end devices (termed "routers" in this use case)
   are typically installed on utility poles throughout the service
   territory.  Router devices are typically less constrained than
   meters, and often contain the full routing table for all the
   endpoints routing through them.




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   In this use case, the utility typically installs on the order of 1000
   meters per router.  The collection of meters comprised in a local
   network that are routing through a specific router is called in this
   use case a Local Meter Network (LMN).  When powered on, each meter is
   designed to discover the nearby LMNs, select the optimal LMN to join,
   and select the optimal meters in that LMN to route through when
   sending data to the headend.  After joining the LMN, the meter is
   designed to continuously monitor and optimize its connection to the
   LMN, and it may change routes and LMNs as needed.

   Each LMN may be configured e.g. to share an encryption key, providing
   confidentiality for all data traffic within the LMN.  This key may be
   obtained by a meter only after an end-to-end authentication process
   based on certificates, ensuring that only authorized and
   authenticated meters are allowed to join the LMN, and by extension,
   the mesh network as a whole.

   After joining the LMN, each endpoint obtains a routable and possibly
   private IPv6 address that enables end-to-end communication between
   the headend systems and each meter.  In this use case, the meters are
   always-on.  However, due to lossy links and network optimization, not
   every meter will be immediately accessible, though eventually every
   meter will be able to exchange data with the headend.

   In a large AMI deployment, there may be 10 million meters supported
   by 10.000 routers, spread across a very large geographic area.
   Within a single LMN, the meters may range between 1 and approx. 20
   hops from the router.  During the deployment process, these meters
   are installed and turned on in large batches, and those meters must
   be authenticated, given addresses, and provisioned with any
   configuration information necessary for their operation.  During
   deployment and after deployment is finished, the network must be
   monitored continuously and failures must be handled.  Configuration
   parameters may need to be changed on large numbers of devices, but
   most of the devices will be running the same configuration.
   Moreover, eventually, the firmware in those meters will need to be
   upgraded, and this must also be done in large batches because most of
   the devices will be running the same firmware image.

   Because there may be thousands of routers, this operational model
   (batch deployment, automatic provisioning, continuous monitoring,
   batch reconfiguration, batch firmware update) should also apply to
   the routers as well as the constrained devices.  The scale is
   different (thousands instead of millions) but still large enough to
   make individual management impractical for routers as well.






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3.12.  MANET Concept of Operations (CONOPS) in Military

   The use case on the Concept of Operations (CONOPS) focuses on the
   configuration and monitoring of networks that are currently being
   used in military and as such, it offers insights and challenges of
   network management that military agencies are facing.

   As technology advances, military networks nowadays become large and
   consist of varieties of different types of equipments that run
   different protocols and tools that obviously increase complexity of
   the tactical networks.  Moreover, lacks of open common interfaces and
   Application Programming Interface (API) are often a challenge to
   network management.  Configurations are, most likely, manually
   performed.  Some devices do not support IP networks.  Integration and
   evaluation process are no longer trivial for a large set of protocols
   and tools.  In addition, majority of protocols and tools developed by
   vendors that are being used are proprietary which makes integration
   more difficult.  The main reason that leads to this problem is that
   there is no clearly defined standard for the MANET Concept of
   Operations (CONOPS).  In the following, a set of scenarios of network
   operations are described, which might lead to the development of
   network management protocols and a framework that can potentially be
   used in military networks.

   Note: The term "node" is used at IETF for either a host or router.
   The term "unit" or "mobile unit" in military (e.g.  Humvees, tanks)
   is a unit that contains multiple routers, hosts, and/or other non-IP-
   based communication devices.

   Scenario: Parking Lot Staging Area:

   The Parking Lot Staging Area is the most common network operation
   that is currently widely used in military prior to deployment.  MANET
   routers, which can be identical such as the platoon leader's or
   rifleman's radio, are shipped to a remote location along with a Fixed
   Network Operations Center (NOC), where they are all connected over
   traditional wired or wireless networks.  The Fixed NOC then performs
   mass-configuration and evaluation of configuration processes.  The
   same concept can be applied to mobile units.  Once all units are
   successfully configured, they are ready to be deployed.











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   +---------+             +----------+
   |  Fixed  |<---+------->| router_1 |
   |   NOC   |    |        +----------+
   +---------+    |
                  |        +----------+
                  +------->| router_2 |
                  |        +----------+
                  |            0
                  |            0
                  |            0
                  |        +----------+
                  +------->| router_N |
                           +----------+


                    Figure 1: Parking Lot Staging Area

   Scenario: Monitoring with SatCom Reachback:

   The Monitoring with SatCom Reachback, which is considered another
   possible common scenario to military's network operations, is similar
   to the Parking Lot Staging Area.  Instead, the Fixed NOC and MANET
   routers are connected through a Satellite Communications (SatCom)
   network.  The Monitoring with SatCom Reachback is a scenario where
   MANET routers are augmented with SatCom Reachback capabilities while
   On-The-Move (OTM).  Vehicles carrying MANET routers support multiple
   types of wireless interfaces, including High Capacity Short Range
   Radio interfaces as well as Low Capacity OTM SatCom interfaces.  The
   radio interfaces are the preferred interfaces for carrying data
   traffic due to their high capacity, but the range is limiting with
   respect to connectivity to a Fixed NOC.  Hence, OTM SatCom interfaces
   offer a more persistent but lower capacity reachback capability.  The
   existence of a SatCom persistent Reachback capability offers the NOC
   the ability to monitor and manage the MANET routers over the air.
   Similarly to the Parking Lot Staging scenario, the same concept can
   be applied to mobile units.















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                            ---   +--+    ---
                           /  /---|SC|---/  /
                           ---    +--+   ---
   +---------+                      |
   |  Fixed  |<---------------------+
   |   NOC   |       +--------------|
   +---------+       |              +-------------------+
                     |              |                   |
                 +----------+       |               +----------+
                 | router_1 |       +----------+    | router_N |
                 +----------+       |          |    +----------+
                     *              |          |      *   *
                     *        +----------+     |      *   *
                     *********| router_2 |*****|*******   *
                              +----------+     |          *
                                   *           |          *
                                   *       +----------+   *
                                   ********| router_3 |****
                                           +----------+

         ---  SatCom links
         ***  Radio links


        Figure 2: Monitoring with one-hop SatCom Reachback network

   Scenario: Hierarchical Management:

   Another reasonable scenario common to military operations in a MANET
   environment is the Hierarchical Management scenario.  Vehicles carry
   a rather complex set of networking devices, including routers running
   MANET control protocols.  In this hierarchical architecture, the
   MANET mobile unit has a rather complex internal architecture where a
   local manager within the unit is responsible for local management.
   The local management includes management of the MANET router and
   control protocols, the firewall, servers, proxies, hosts and
   applications.  In addition, a standard management interface is
   required in this architecture.  Moreover, in addition to requiring
   standard management interfaces into the components comprising the
   MANET nodal architecture, the local manager is responsible for local
   monitoring and the generation of periodic reports back to the Fixed
   NOC.









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                               Interface
                               |
                               V
   +---------+             +-------------------------+
   |  Fixed  |  Interface  | +---+     +---+         |
   |   NOC   |<---+------->| | R |--+--| F |         |
   +---------+    |        | +---+  |  +---+         |
                  |        |        |    |  +---+    |
                  |        | +---+  |    +--| P |    |
                  |        | | M |--+    |  +---+    |
                  |        | +---+       |           |
                  |        |             |  +---+    |
                  |        |             +--| D |    |
                  |        |             |  +---+    |
                  |        |             |           |
                  |        |             |  +---+    |
                  |        |             +--| H |    |
                  |        |             |  +---+    |
                  |        | unit_1                  |
                  |        +-------------------------+
                  |
                  |
                  |        +--------+
                  +------->| unit_2 |
                  |        +--------+
                  |             0
                  |             0
                  |             0
                  |        +--------+
                  +------->| unit_N |
                           +--------+

         Key: R-Router
              F-Firewall
              P-PEP (Performance Enhancing Proxy)
              D-Servers, e.g., DNS
              H-hosts
              M-Local Manager



                     Figure 3: Hierarchical Management

   Scenario: Management over Lossy/Intermittent Links:

   In the future of military operations, the standard management will be
   done over lossy and intermittent links and ideally the Fixed NOC will
   become mobile.  In this architecture, the nature and current quality



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   of each link are distinct.  However, there are a number of issues
   that would arise and need to be addressed:

   1.  Common and specific configurations are undefined:

       A.  When mass-configuring devices, common set of configurations
           are undefined at this time.

       B.  Similarly, when performing a specific device, set of specific
           configurations is unknown.

   2.  Once the total number of units becomes quite large, scalability
       would be an issue and need to be addressed.

   3.  The state of the devices are different and may be in various
       states of operations, e.g., ON/OFF, etc.

   4.  Pushing large data files over reliable transport, e.g., TCP,
       would be problematic.  Would a new mechanism of transmitting
       large configurations over the air in low bandwidth be
       implemented?  Which protocol would be used at transport layer?

   5.  How to validate network configuration (and local configuration)
       is complex, even when to cutover is an interesting question.

   6.  Security as a general issue needs to be addressed as it could be
       problematic in military operations.




   +---------+             +----------+
   |  Mobile |<----------->| router_1 |
   |   NOC   |?--+         +----------+
   +---------+    |
         ^        |        +----------+
         |        +------->| router_2 |
         |                 +----------+
         |                     0
         |                     0
         |                     0
         |                 +----------+
         +---------------->| router_N |
                           +----------+


            Figure 4: Management over Lossy/intermittent Links




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4.  Requirements on the Management of Networks with Constrained Devices

   This section describes the requirements categorized by management
   areas listed in subsections.

   Note that the requirements in this section need to be seen as
   standalone requirements.  A device might be able to provide selected
   requirements but might not be capable to provide all requirements at
   once.  On the other hand a device vendor might select a subset of the
   requirements to implement.  As of today this document does not
   recommend the realization of a profile of requirements.

   Following template is used for the definition of the requirements.

   Req-ID:  An ID uniquely identified by a three-digit number

   Title:  The title of the requirement.

   Description:  The rational and description of the requirement.

   Source:  The origin of the requirement and the matching use case or
      application.

   Requirement Type:  Functional Requirement, Non-Functional
      Requirement, Design Constraint

   Device type:  The device types by which this requirement can be
      supported: C0, C1 and/or C2.

   Priority:  The priority of the requirement showing the importance:
      Mandatory (M), Optional (O), Conditional (C).

4.1.  Management Architecture/System

   Req-ID:  4.1.001

   Title:  Support multiple device classes within a single network.

   Description:  Larger networks usually are made up of devices
      belonging to different device classes (e.g., constrained mesh
      endpoints and less constrained routers) that work together.
      Hence, the management architecture must be applicable to networks
      that have a mix of different device classes.  See Section 3. of
      [LWIG-TERMS] for the definition of Constrained Device Classes.







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   Source:  All use cases.

   Requirement Type:  Non-Functional Requirement

   Device type:  Managing and intermediary entities.

   Priority:  Mandatory

   ---

   Req-ID:  4.1.002

   Title:  Management scalability.

   Description:  The management architecture must be able to scale with
      the number of devices involved and operate efficiently in any
      network size and topology.  This implies that e.g. the managing
      entity is able to handle huge amount of device monitoring data and
      the management protocol is not sensitive to the decrease of the
      time between two client requests.  To achieve good scalability,
      caching techniques, in-network data aggregation techniques,
      hierarchical management models may be used.

   Source:  General requirement for all use cases to enable large scale
      networks.

   Requirement Type:  Design Constraint

   Device type:  C0, C1, and C2

   Priority:  Mandatory

   ---

   Req-ID:  4.1.003

   Title:  Hierarchical management

   Description:  Provide a means of hierarchical management, i.e.
      provide intermediary management entities on different levels,
      which can take over the responsibility for the management of a
      sub-hierarchy of the network of constraint devices.  The
      intermediary management entity can e.g. support management data
      aggregation to handle e.g. high-frequent monitoring data or
      provide a caching mechanism for the uplink and downlink
      communication.  Hierarchical management contributes to management
      scalability.




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   Source:  Use cases where a huge amount of devices are deployed with a
      hierarchical topology.

   Requirement Type:  Non-Functional Requirement

   Device type:  Managing and intermediary entities.

   Priority:  Optional

   ---

   Req-ID:  4.1.004

   Title:  Minimize state maintained on constrained devices.

   Description:  The amount of state that needs to be maintained on
      constrained devices should be minimized.  This is important in
      order to save memory (especially relevant for C0 and C1 devices)
      and in order to allow devices to restart for example to apply
      configuration changes or to recover from extended periods of
      inactivity.  One way to achieve this is to adopt a RESTful
      architecture that minimizes the amount of state maintained by
      managed constrained devices and that makes resources of a device
      addressable via URIs.

   Source:  Basic requirement which concerns all use cases.

   Requirement Type:  Non-Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory

   ---

   Req-ID:  4.1.005

   Title:  Automatic re-synchronization with eventual consistency.

   Description:  To support large scale networks, where some constrained
      devices may be offline at any point in time, it is necessary to
      distribute configuration parameters in a way that allows temporary
      inconsistencies but eventually converges, after a sufficiently
      long period of time without further changes, towards global
      consistency.






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   Source:  Use cases with large scale networks with many devices.

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory

   ---

   Req-ID:  4.1.006

   Title:  Support for lossy links and unreachable devices.

   Description:  Some constrained devices will only be able to support
      lossy and unreliable links characterized by a limited data rate, a
      high latency, and a high transmission error rate.  Furthermore
      constrained devices often duty cycle their radio or the whole
      device in order to save energy.  In both cases the management
      system must not assume that constrained devices are always
      reachable.  The management protocol(s) must act gracefully if a
      conctrained device is not reachable and provide a high degree of
      resilience.  Intermediaries may be used that provide information
      for devices currently inactive or that take responsibility to re-
      synchronize devices when they become reachable again after an
      extended offline period.

   Source:  Basic requirement for constrained networks with unreliable
      links and constrained devices which sleep to save energy.

   Requirement Type:  Design Constraint

   Device type:  C0, C1, and C2

   Priority:  Mandatory

   ---

   Req-ID:  4.1.007

   Title:  Network-wide configuration

   Description:  Provide means by which the behavior of the network can
      be specified at a level of abstraction (network-wide
      configuration) higher than a set of configuration information
      specific to individual devices.  It is useful to derive the device
      specific configuration from the network-wide configuration.  The
      identification of the relevant subset of the policies to be



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      provisioned is according to the capabilities of each device and
      can be obtained from a pre-configured data-repository.  Such a
      repository can be used to configure pre-defined device or protocol
      parameters for the whole network.  Furthermore, such a network-
      wide view can be used to monitor and manage a group of routers or
      a whole network.  E.g. monitoring the performance of a network
      requires additional information other than what can be acquired
      from a single router using a management protocol.

   Source:  In general all use cases, which want to configure the
      network and its devices based on a network view in a top-down
      manner.

   Requirement Type:  Non-Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Optional

   ---

   Req-ID:  4.1.008

   Title:  Distributed Management

   Description:  Provide a means of simple distributed management, where
      a constrained network can be managed or monitored by more than one
      manager.  Since the connectivity to a server cannot be guaranteed
      at all times, a distributed approach may provide a higher
      reliability, at the cost of increased complexity.  This
      requirement implies the handling of data consistency in case of
      concurrent read and write access to the device datastore.  It
      might also happen that no management (configuration) server is
      accessible and the only reachable node is a peer device.  In this
      case the device should be able to obtain its configuration from
      peer devices.

   Source:  Use cases where the count of devices to manage is high.

   Requirement Type:  Non-Functional Requirement

   Device type:  C1 and C2

   Priority:  Optional







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4.2.  Management protocols and data model

   Req-ID:  4.2.001

   Title:  Modular implementation of management protocols

   Description:  Management protocols should allow modular
      implementations, i.e., it should be possible to implement only a
      basic set of protocol primitives on highly constrained devices
      while devices with additional resources may provide more support
      for additional protocol primitives.  It should be possible to
      discover the management protocol primitives by a device.

   Source:  Basic requirement interesting for all use cases.

   Requirement Type:  Non-Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory

   ---

   Req-ID:  4.2.002

   Title:  Compact encoding of management data

   Description:  The encoding of management data should be compact and
      space efficient, enabling small message sizes.

   Source:  General requirement to save memory for the receiver buffer
      and on-air bandwith.

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory

   ---

   Req-ID:  4.2.003

   Title:  Compression of management data or complete messages







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   Description:  Management data exchanges can be further optimized by
      applying data compression techniques or delta encoding techniques.
      Compression typically requires additional code size and some
      additional buffers and/or the maintenance of some additional state
      information.  For C0 devices compression may not be feasible.  As
      such, this requirement is marked as optional.

   Source:  Use cases where it is beneficial to reduce transmission time
      and bandwith, e.g. mobile applications which require to save on-
      air bandwith.

   Requirement Type:  Functional Requirement

   Device type:  C1 and C2

   Priority:  Optional

   ---

   Req-ID:  4.2.004

   Title:  Mapping of management protocol interactions.

   Description:  It is desirable to have a loss-less automated mapping
      between the management protocol used to manage constrained devices
      and the management protocols used to manage regular devices.  In
      the ideal case, the same core management protocol can be used with
      certain restrictions taking into account the resource limitations
      of constrained devices.  However, for very resource constrained
      devices, this goal might not be achievable.  Hence this
      requirement is marked optional for device class C2.

   Source:  Use cases where high-frequent interaction with the
      management system of a non-constrained network is required.

   Requirement Type:  Functional Requirement

   Device type:  C2

   Priority:  Optional

   ---

   Req-ID:  4.2.005







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   Title:  Consistency of data models with the underlying information
      model.

   Description:  The data models used by the management protocol must be
      consistent with the information model used to define data models
      for non-constrained networks.  This is essential to facilitate the
      integration of the management of constrained networks with the
      management of non-constrained networks.  Using an underlying
      information model for future data model design enables furthermore
      top-down model design and model reuse as well as data
      interoperability (i.e. exchange of management information between
      the constrained and non-constrained networks).  This is a strong
      requirement, even despite the fact that the underlying information
      models are often not explicitly documented in the IETF.

   Source:  General requirement to support data interoperability,
      consistency and model reuse.

   Requirement Type:  Non-Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory

   ---

   Req-ID:  4.2.006

   Title:  Loss-less mapping of management data models.

   Description:  It is desirable to have a loss-less automated mapping
      between the management data models used to manage regular devices
      and the management data models used for managing constrained
      devices.  In the ideal case, the same core data models can be used
      with certain restrictions taking into account the resource
      limitations of constrained devices.  However, for very resource
      constrained devices, this goal might not be achievable.  Hence
      this requirement is marked optional for device class C2.

   Source:  Use cases where consistent data exchange with the management
      system of a non-constrained network is required.

   Requirement Type:  Functional Requirement

   Device type:  C2






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   Priority:  Optional

   ---

   Req-ID:  4.2.007

   Title:  Protocol extensibility

   Description:  Provide means of extensibility for the management
      protocol, i.e. by adding new protocol messages or mechanisms that
      can deal with the changing requirements on a supported message and
      data types effectively, without causing inter-operability problems
      or having to replace/update large amounts of deployed devices.

   Source:  Basic requirement useful for all use cases.

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory

4.3.  Configuration management

   Req-ID:  4.3.001

   Title:  Self-configuration capability

   Description:  Automatic configuration and re-configuration of devices
      without manual intervention.  Compared to the traditional
      management of devices where the management application is the
      central entity configuring the devices, in the auto-configuration
      scenario the device is the active part and initiates the
      configuration process.  Self-configuration can be initiated during
      the initial configuration or for subsequent configurations, where
      the configuration data needs to be refreshed.  Self-configuration
      should be also supported during the initialization phase or in the
      event of failures, where prior knowledge of the network topology
      is not available or the topology of the network is uncertain.

   Source:  In general all use cases requiring easy deployment and plug&
      play behavior as well as easy maintenance of many constrained
      devices.

   Requirement Type:  Functional Requirement






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   Device type:  C0, C1, and C2

   Priority:  Mandatory for C0 and C1, Optional for C2.

   ---

   Req-ID:  4.3.002

   Title:  Capability Discovery

   Description:  Enable the discovery of supported optional management
      capabilities of a device and their exposure via at least one
      protocol and/or data model.

   Source:  Use cases where the device interaction with other devices or
      applications is a function of the level of support for its
      capabilities.

   Requirement Type:  Functional Requirement

   Device type:  C1 and C2

   Priority:  Optional

   ---

   Req-ID:  4.3.003

   Title:  Asynchronous Transaction Support

   Description:  Provide configuration management with asynchronous
      transaction support.  Configuration operations must support a
      transactional model, with asynchronous indications that the
      transaction was completed.

   Source:  Use cases, which require transaction-oriented processing
      because of reliability or distributed architecture functional
      requirements.

   Requirement Type:  Functional Requirement

   Device type:  C1 and C2

   Priority:  Conditional

   ---





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   Req-ID:  4.3.004

   Title:  Network reconfiguration

   Description:  Provide a means of iterative network reconfiguration in
      order to recover the network functionality from node and
      communication faults.  The network reconfiguration can be failure-
      driven and self-initiated (automatic reconfiguration).  The
      network reconfiguration can be also performed on the whole
      hierarchical structure of a network (network topology).

   Source:  Practically all use cases, as network connectivity is a
      basic requirement.

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory, Conditional if the network has a hierarchical
      topology.

4.4.  Monitoring functionality

   Req-ID:  4.4.001

   Title:  Device status monitoring

   Description:  Provide a monitoring function to collect and expose
      information about device status and exposing it via at least one
      management interface.  The device monitoring might make use of the
      hierarchical management through the intermediary entities and the
      data caching mechanism.  The device monitoring might also make use
      of neighbor-monitoring (fault detection in local network) to
      support fast fault detection and recovery, e.g. in a scenario
      where a managing entity is unreachable and a neighbor can take
      over the monitoring responsibility.

   Source:  All use cases

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory, Conditional for neighbor-monitoring.

   ---





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   Req-ID:  4.4.002

   Title:  Energy status monitoring

   Description:  Provide a monitoring function to collect and expose
      information about device energy parameters and usage (e.g. battery
      level and communication power).

   Source:  Use case Energy Management

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory for energy reporting devices, Optional for the
      rest

   ---

   Req-ID:  4.4.003

   Title:  Monitoring of current and estimated device availability

   Description:  Provide a monitoring function to collect and expose
      information about current device availability (energy, memory,
      computing power, forwarding plane utilization, queue buffers,
      etc.) and estimation of remaining available resources.

   Source:  All use cases.  Note that monitoring energy resources (like
      battery status) may be required on all kinds of devices.

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Optional

   ---

   Req-ID:  4.4.004

   Title:  Network status monitoring

   Description:  Provide a monitoring function to collect and expose
      information related to the status of a network or network segments
      connected to the interfaces of the device.





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   Source:  All use cases.

   Requirement Type:  Functional Requirement

   Device type:  C1 and C2

   Priority:  Optional

   ---

   Req-ID:  4.4.005

   Title:  Self-monitoring

   Description:  Provide self-monitoring (local fault detection) feature
      for fast fault detection and recovery.

   Source:  Use cases where the devices cannot be monitored centrally in
      appropriate manner, e.g. self-healing is required.

   Requirement Type:  Functional Requirement

   Device type:  C1 and C2

   Priority:  Mandatory for C2, Optional for C1

   ---

   Req-ID:  4.4.006

   Title:  Performance Monitoring

   Description:  The device will provide a monitoring function to
      collect and expose information about the basic TBD performance of
      the device.  The performance management functionality might make
      use of the hierarchical management through the intermediary
      devices.

   Source:  Use cases Building automation, and Transport applications

   Requirement Type:  Functional Requirement

   Device type:  C1 and C2

   Priority:  Optional

   ---




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   Req-ID:  4.4.007

   Title:  Fault detection monitoring

   Description:  The device will provide fault detection monitoring.
      The system collects information about network states in order to
      identify whether faults have occurred.  In some cases the
      detection of the faults might be based on the processing and
      analysis of the parameters retrieved from the network or other
      devices.  In case of C0 devices the monitoring might be limited to
      the check whether the device is alive or not.

   Source:  Use cases Environmental Monitoring, Building Automation,
      Energy Management, Infrastructure Monitoring

   Requirement Type:  Functional Requirement

   Device type:  C0, C1 and C2

   Priority:  Optional

   ---

   Req-ID:  4.4.008

   Title:  Passive and Reactive Monitoring

   Description:  The device will provide passive and reactive monitoring
      capabilities.  The system or manager collects information about
      device components and network states (passive monitoring) and may
      perform postmortem analysis of collected data.  In case events of
      interest have occurred the system or manager can adaptively react
      (reactive monitoring), e.g. reconfigure the network.  Typically
      actions (re-actions) will be executed or sent as commands by the
      management applications.

   Source:  Diverse use cases relevant for device status and network
      state monitoring

   Requirement Type:  Functional Requirement

   Device type:  C2

   Priority:  Optional

   ---





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   Req-ID:  4.4.009

   Title:  Recovery

   Description:  Provide local, central and hierarchical recovery
      mechanisms (recovery is in some cases achieved by recovering the
      whole network of constrained devices).

   Source:  Use cases Industrial applications, Home and Building
      Automation, Mobile Applications that involve different forms of
      clustering or area managers.

   Requirement Type:  Functional Requirement

   Device type:  C2

   Priority:  Optional

   ---

   Req-ID:  4.4.010

   Title:  Network topology discovery

   Description:  Provide a network topology discovery capability (e.g.
      use of topology extraction algorithms to retrieve the network
      state) and a monitoring function to collect and expose information
      about the network topology.

   Source:  Use cases Community Network Applications and Mobile
      Applications

   Requirement Type:  Functional Requirement

   Device type:  C1 and C2

   Priority:  Optional

   ---

   Req-ID:  4.4.011

   Title:  Notifications

   Description:  The device will provide the capability of sending
      notifications on critical events and faults.





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   Source:  All use cases.

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory for C2, Optional for C1

   ---

   Req-ID:  4.4.012

   Title:  Logging

   Description:  The device will provide the capability of building,
      keeping, and allowing retrieval of logs of events (including but
      not limited to critical faults and alarms).

   Source:  Use cases Industrial Applications, Building Automation,
      Infrastructure monitoring

   Requirement Type:  Functional Requirement

   Device type:  C2

   Priority:  Mandatory for some medical or industrial applications,
      Optional otherwise

4.5.  Self-management

   Req-ID:  4.5.001

   Title:  Self-management - Self-healing

   Description:  Enable event-driven and/or periodic self-management
      functionality in a device.  The device should be able to react in
      case of a failure e.g. by initiating a fully or partly reset and
      initiate a self-configuration or management data update as
      necessary.  A device might be further able to check for failures
      cyclically or schedule-controlled to trigger self-management as
      necessary.  It is a matter of device design and subject for
      discussion how much self-management a C1 device can support.  A
      minimal failure detection and self-management logic is assumed to
      be generally useful for the self-healing of a device.







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   Source:  The requirement generally relates to all use cases in this
      document.

   Requirement Type:  Functional Requirement

   Device type:  C1 and C2

   Priority:  Optional

4.6.  Security and Access Control

   Req-ID:  4.6.001

   Title:  Authentication of management system and devices.

   Description:  Systems having a management role must be properly
      authenticated to the device such that the device can exercise
      proper access control and in particular distinguish rightful
      management systems from rogue systems.  On the other hand managed
      devices must authenticate themselves to systems having a
      management role such that management systems can protect
      themselves from rogue devices.  In certain application scenarios,
      it is possible that a large number of devices need to be
      (re)started at about the same time.  Protocols and authentication
      systems should be designed such that a large number of devices
      (re)starting simultaneously does not negatively impact the device
      authentication process.

   Source:  Basic security requirement for all use cases.

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory, Optional for the (re)start of a large number of
      devices

   ---

   Req-ID:  4.6.002

   Title:  Support suitable security bootstrapping mechanisms

   Description:  Mechanisms should be supported that simplify the
      bootstrapping of device that is the discovery of newly deployed
      devices in order to add them to access control lists.





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   Source:  Basic security requirement for all use cases.

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory

   ---

   Req-ID:  4.6.003

   Title:  Access control on management system and devices

   Description:  Systems acting in a management role must provide an
      access control mechanism that allows the security administrator to
      restrict which devices can access the managing system (e.g., using
      an access control white list of known devices).  On the other hand
      managed constrained devices must provide an access control
      mechanism that allows the security administrator to restrict how
      systems in a management role can access the device (e.g., no-
      access, read-only access, and read-write access).

   Source:  Basic security requirement for use cases where access
      control is essential.

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory

   ---

   Req-ID:  4.6.004

   Title:  Select cryptographic algorithms that are efficient in both
      code space and execution time.

   Description:  Cryptographic algorithms have a major impact in terms
      of both code size and overall execution time.  It is therefore
      necessary to select mandatory to implement cryptographic
      algorithms (like some elliptic curve algorithm) that are
      reasonable to implement with the available code space and that
      have a small impact at runtime.  Furthermore some wireless
      technologies (e.g., IEEE 802.15.4) require the support of certain
      cryptographic algorithms.  It might be useful to choose algorithms
      that are likely to be supported in wireless chipsets for certain



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      wireless technologies.

   Source:  Generic requirement to reduce the footprint and CPU usage of
      a constrained device.

   Requirement Type:  Non-Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory, Optional for hardware-supported algorithms.

4.7.  Energy Management

   Req-ID:  4.7.001

   Title:  Management of Energy Resources

   Description:  Enable managing power resources in the network, e.g.
      reduce the sampling rate of nodes with critical battery and reduce
      node transmission power, put nodes to sleep, put single interfaces
      to sleep, reject a management job based on available energy,
      criteria e.g. importance levels pre-defined by the management
      application, etc. (e.g. a task marked as essential can be executed
      even if the energy level is low).  The device may further
      implement standard data models for energy management and expose it
      through a management protocol interface, e.g.  EMAN MIB modules
      and extensions.  It might be necessary to downscale EMAN MIBs for
      the use in C1 and C2 devices.

   Source:  Use case Energy Management

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory for the use case Energy Management, Optional
      otherwise.

   ---

   Req-ID:  4.7.002

   Title:  Support of energy-optimized communication protocols

   Description:  Use of an optimized communication protocol to minimize
      energy usage for the device (radio) receiver/transmitter, on-air
      bandwidth (protocol efficiency), reduced amount of data
      communication between nodes (implies data aggregation and



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      filtering but also a compact format for the transferred data).

   Source:  Use cases Energy Management and Mobile Applications.

   Requirement Type:  Functional Requirement

   Device type:  C2

   Priority:  Optional

   ---

   Req-ID:  4.7.003

   Title:  Support for layer 2 energy-aware protocols

   Description:  The device will support layer 2 energy management
      protocols (e.g. energy-efficient Ethernet IEEE 802.3az) and be
      able to report on these.

   Source:  Use case Energy Management

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Optional

   ---

   Req-ID:  4.7.004

   Title:  Dying gasp

   Description:  When energy resources draw below the red line level,
      the device will send a dying gasp notification and perform if
      still possible a graceful shutdown including conservation of
      critical device configuration and status information.

   Source:  Use case Energy Management

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2







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   Priority:  Optional

4.8.  SW Distribution

   Req-ID:  4.8.001

   Title:  Group-based provisioning

   Description:  Support group-based provisioning, i.e. firmware update
      and configuration management, of a large set of constrained
      devices with eventual consistency and coordinated reload times.
      The device should accept group-based configuration management
      based on bulk commands, which aim similar configurations of a
      large set of constrained devices of the same type in a given
      group.  Activation of configuration may be based on pre-loaded
      sets of default values.

   Source:  All use cases

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Optional

4.9.  Traffic management

   Req-ID:  4.9.001

   Title:  Congestion avoidance

   Description:  Provide the ability to avoid congestion by modifying
      the device's reporting rate for periodical data (which is usually
      redundant) based on the importance and reliability level of the
      management data.  This functionality is usually controlled by the
      managing entity, where the managing entity marks the data as
      important or relevant for reliability.  However reducing a
      device's reporting rate can also be initiated by a device if it is
      able to detect congestion or has insufficient buffer memory.

   Source:  Use cases with high reporting rate and traffic e.g.  AMI or
      M2M.

   Requirement Type:  Design Constraint







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   Device type:  C1 and C2

   Priority:  Optional

   ---

   Req-ID:  4.9.002

   Title:  Redirect traffic

   Description:  Provide the ability for network nodes to redirect
      traffic from overloaded intermediary nodes in a network to another
      path in order to prevent congestion on a central server and in the
      primary network.

   Source:  Use cases with high reporting rate and traffic e.g.  AMI or
      M2M.

   Requirement Type:  Design Constraint

   Device type:  Intermediary entity in the network.

   Priority:  Optional

   ---

   Req-ID:  4.9.003

   Title:  Traffic delay schemes.

   Description:  Provide the ability to apply delay schemes to incoming
      and outgoing links on an overloaded intermediary node as necessary
      in order to reduce the amount of traffic in the network.

   Source:  Use cases with high reporting rate and traffic e.g.  AMI or
      M2M.

   Requirement Type:  Design Constraint

   Device type:  Intermediary entity in the network.

   Priority:  Optional

4.10.  Transport Layer







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   Req-ID:  4.10.001

   Title:  Scalable transport layer

   Description:  Enable the use of a scalable transport layer, i.e. not
      sensitive to the decrease of the time between two client requests,
      which is useful for applications requiring frequent access to
      device data.

   Source:  Applications with high frequent access to the device data.

   Requirement Type:  Design Constraint

   Device type:  C0, C1 and C2

   Priority:  Conditional, in case such scalability is a prerequisite.

   ---

   Req-ID:  4.10.002

   Title:  Reliable unicast transport.

   Description:  Provide reliable unicast transport of messages.

   Source:  Generally all applications benefit from the reliability of
      the message transport.

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Mandatory

   ---

   Req-ID:  4.10.003

   Title:  Best-effort multicast

   Description:  Provide best-effort multicast of messages, which is
      generally useful when devices need to discover a service provided
      by a server or many devices need to be configured by a managing
      entity at once based on the same data model.







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   Source:  Use cases where a device needs to discover services as well
      as use cases with high amount of devices to manage, which are
      hierarchically deployed, e.g.  AMI or M2M.

   Requirement Type:  Functional Requirement

   Device type:  C0, C1, and C2

   Priority:  Optional

   Req-ID:  4.10.004

   Title:  Secure message transport.

   Description:  Enable secure message transport providing
      authentication, data integrity, confidentiality by using existing
      transport layer technologies with small footprint such as TLS/
      DTLS.

   Source:  All use cases.

   Requirement Type:  Non-Functional Requirements

   Device type:  C1 and C2

   Priority:  Mandatory

4.11.  Implementation Requirements

   Req-ID:  4.11.001

   Title:  Avoid complex application layer transactions requiring large
      application layer messages.

   Description:  Complex application layer transactions tend to require
      large memory buffers that are typically not available on C0 or C1
      devices and only by limiting functionality on C2 devices.
      Furthermore, the failure of a single large transaction requires
      repeating the whole transaction.  On constrained devices, it is
      often more desirable to a large transaction down into a sequence
      of smaller transactions, which require less resources and allow to
      make progress using a sequence of smaller steps.

   Source:  Basic requirement which concerns all use cases with memory
      constrained devices.






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   Requirement Type:  Design Constraint

   Device type:  C0, C1, and C2

   Priority:  Mandatory

   Req-ID:  4.11.002

   Title:  Avoid reassembly of messages at multiple layers in the
      protocol stack.

   Description:  Reassembly of messages at multiple layers in the
      protocol stack requires buffers at multiple layers, which leads to
      inefficient use of memory resources.  This can be avoided by
      making sure the application layer, the security layer, the
      transport layer, the IPv6 layer and any adaptation layers are
      aware of the limitations of each other such that unnecessary
      fragmentation and reassembly can be avoided.  In addition, message
      size constraints must be announced to protocol peers such that
      they can adapt and avoid sending messages that can't be processed
      due to resource constraints on the receiving device.

   Source:  Basic requirement which concerns all use cases with memory
      constrained devices.

   Requirement Type:  Design Constraint

   Device type:  C0, C1, and C2

   Priority:  Mandatory





















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5.  IANA Considerations

   This document does not introduce any new code-points or namespaces
   for registration with IANA.

   Note to RFC Editor: this section may be removed on publication as an
   RFC.












































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6.  Security Considerations

   This document discusses the use cases and requirements on the network
   of constrained devices.  If specific requirements for security will
   be identified, they will be described in future versions of this
   document.













































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7.  Contributors

   Following persons made significant contributions to and reviewed this
   document:

   o  Ulrich Herberg (Fujitsu Laboratories of America) contributed the
      Section 3.9 on Community Network Applications and to the
      Section 1.3 on Class of Networks in Focus.

   o  Peter van der Stok contributed to Section 3.5 on Building
      Automation.

   o  Zhen Cao contributed to Section 3.10 on Mobile Applications.

   o  Gilman Tolle contributed the Section 3.11 on Automated Metering
      Infrastructure.

   o  James Nguyen and Ulrich Herberg contributed the Section 3.12 on
      MANET Concept of Operations (CONOPS) in Military.
































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8.  Acknowledgments

   The editors would like to thank the contributors and the participants
   on the Coman maillist for their valuable contributions and comments.















































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9.  References

9.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

9.2.  Informative References

   [RFC6632]  Ersue, M. and B. Claise, "An Overview of the IETF Network
              Management Standards", RFC 6632, June 2012.

   [RFC6130]  Clausen, T., Dearlove, C., and J. Dean, "Mobile Ad Hoc
              Network (MANET) Neighborhood Discovery Protocol (NHDP)",
              RFC 6130, April 2011.

   [RFC6779]  Herberg, U., Cole, R., and I. Chakeres, "Definition of
              Managed Objects for the Neighborhood Discovery Protocol",
              RFC 6779, October 2012.

   [I-D.ietf-manet-olsrv2]
              Clausen, T., Dearlove, C., Jacquet, P., and U. Herberg,
              "The Optimized Link State Routing Protocol version 2",
              draft-ietf-manet-olsrv2-17 (work in progress),
              October 2012.

   [I-D.ietf-lwig-guidance]
              Bormann, C., "Guidance for Light-Weight Implementations of
              the Internet Protocol Suite", draft-ietf-lwig-guidance-02
              (work in progress), August 2012.

   [I-D.ietf-core-coap]
              Shelby, Z., Hartke, K., Bormann, C., and B. Frank,
              "Constrained Application Protocol (CoAP)",
              draft-ietf-core-coap-13 (work in progress), December 2012.

   [I-D.ietf-eman-framework]
              Claise, B., Parello, J., Schoening, B., Quittek, J., and
              B. Nordman, "Energy Management Framework",
              draft-ietf-eman-framework-06 (work in progress),
              October 2012.

   [I-D.ietf-eman-requirements]
              Quittek, J., Chandramouli, M., Winter, R., Dietz, T., and
              B. Claise, "Requirements for Energy Management",
              draft-ietf-eman-requirements-11 (work in progress),
              January 2013.




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   [I-D.ietf-roll-terminology]
              Vasseur, J., "Terminology in Low power And Lossy
              Networks", draft-ietf-roll-terminology-10 (work in
              progress), January 2013.

   [M2MDEVCLASS]
              Open Mobile Alliance, "OMA M2M Device Classification
              v1.0", October 2012, <http://
              technical.openmobilealliance.org/Technical/
              release_program/m2m_Device_class_v1_0.aspx>.

   [EU-IOT-A]
              EU Commission Seventh Framework Programme, "EU FP7 Project
              Internet-of-Things Architecture", <http://www.iot-a.eu/>.

   [EU-SENSEI]
              EU Commission Seventh Framework Programme, "EU Project
              SENSEI", <http://www.sensei-project.eu/>.

   [EU-FI-WARE]
              EU Commission Future Internet Public Private Partnership
              (FI-PPP), "EU Project Future Internet-Core Platform",
              <http://www.iot-butler.eu/>.

   [EU-IOT-BUTLER]
              EU Commission Seventh Framework Programme, "EU FP7 Project
              Butler Smartlife", <http://www.iot-butler.eu/>.

   [LWIG-TERMS]
              Bormann, C., "Terminology for Constrained Node Networks",
              draft-bormann-lwig-terms (work in progress),
              November 2012.



















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Appendix A.  Related Development in other Bodies

   Note that over time the summary on the related work in other bodies
   might become outdated.

A.1.  ETSI TC M2M

   ETSI Technical Committee Machine-to-Machine (ETSI TC M2M) aims to
   provide an end-to-end view of M2M standardization, which enables the
   integration of multiple vertical M2M applications.  The main goal is
   to overcome the current M2M market fragmentation and to reuse
   existing mechanisms from telecom standards such as from OMA or 3GPP.

   ETSI Release 1 is functionally frozen.  The main focus is on use
   cases for Smart Metering (Technical Report (TR) 102 691) but it also
   includes eHealth use cases (TR 102 732) and some others.  The Service
   requirements (Technical Standard (TS) 102 689) derived from the use
   cases, and the functional architecture specification (TS 102 690),
   will together define the M2M platform.  The architecture consists of
   Service Capabilities (SC), which are basic functional building blocks
   for building the M2M platform.

   Smart Metering is seen as the important showcase for M2M. It is
   believed that the Service Enablers that were defined based on the
   work done for Smart Metering and eHealth segments will also allow the
   building of other services like vending machines, alarm systems etc.

   The functional architecture includes following management-related
   definitions:

   o  Network Management Functions: consists of all functions required
      to manage the Access, Transport and Core networks: these include
      Provisioning, Supervision, Fault Management, etc.

   o  M2M Management Functions: consists of functions required to manage
      generic functionalities of M2M Applications and M2M Service
      Capabilities in the Network and Applications Domain.  The
      management of the M2M Devices and Gateways may use specific M2M
      Service Capabilities.

   The Release 2 work of ETSI TC M2M has started beginning of 2012.
   Following is a list of networking- and management-related topics
   under work:

   o  Interworking with 3GPP networks.  This is a new work item, and no
      discussion has been held on technical details.  The intent is to
      define which ETSI TC M2M functions are applicable when 3GPP NW is
      used as transport.  It is possible that this work would also cover



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      details on how to use 3GPP interfaces, e.g. those defined in the
      SIMTC work, but also for charging and policy control.

   o  Creating a Semantic Model or Data Abstraction layer for vertical
      industries and interworking.  This would provide some high level
      information description that would be usable for interworking with
      local networks (e.g.  ZigBee), and also for verticals, and it
      would allow the ETSI Service Enablement layer to also understand
      the data, instead of being just a bit storage and bit pipe.  All
      technical details are still under discussion, but it has been
      agreed that a function for this exists in the architecture at
      least for interworking.

A.2.  OASIS

   Developments in OASIS related to management of constrained networks
   are following:

   o  The Energy Interoperation TC works to define interaction between
      Smart Grids and their end nodes, including Smart Buildings,
      Enterprises, Industry, Homes, and Vehicles.  The TC develops data
      and communication models that enable the interoperable and
      standard exchange of signals for dynamic pricing, reliability, and
      emergencies.  The TC's agenda also extends to the communication of
      market participation data (such as bids), load predictability, and
      generation information.  The first version of the Energy
      Interoperation specification is in final review.

   o  OASIS Open Data Protocol (OData) aims to simplify the querying and
      sharing of data across disparate applications and multiple
      stakeholders for re-use in the enterprise, Cloud, and mobile
      devices.  As a REST-based protocol, OData builds on HTTP, AtomPub,
      and JSON using URIs to address and access data feed resources.  It
      enables information to be accessed from a variety of sources
      including (but not limited to) relational databases, file systems,
      content management systems, and traditional Web sites.

   o  Open Building Information Exchange (oBIX) aims to enable the
      mechanical and electrical control systems in buildings to
      communicate with enterprise applications, and to provide a
      platform for developing new classes of applications that integrate
      control systems with other enterprise functions.  Enterprise
      functions include processes such as Human Resources, Finance,
      Customer Relationship Management (CRM), and Manufacturing.







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A.3.  OMA

   OMA is currently working on Lightweight M2M Enabler, OMA Device
   Management (OMA DM) Next Generation, and a white paper on M2M Device
   Classification.

   The Lightweight M2M Enabler covers both M2M device management and
   service management for constrained devices.  In the case of less
   constrained devices, OMA DM Next Generation Enabler may be more
   appropriate.  OMA DM is structured around Management Objects (MO),
   each specified for a specific purpose.  There is also ongoing work
   with various other MOs such as the Gateway Management Object (GwMO).
   A draft for the "Lightweight M2M Requirements" is available.

   OMA Lightweight M2M and OMA DM Next Generation are important to M2M
   device management, provisioning and service managements in both the
   protocol and management objects.  OMA Lightweight M2M work seems to
   have grown from its original scope of being targeted for very simple
   devices only, i.e. such that could not handle all those protocols
   that ETSI M2M requires.

   The white paper on the M2M Device Classification [M2MDEVCLASS]
   provides an M2M device classification framework based on the
   horizontal attributes (e.g., wide or local area communication
   interface, IP stack, I/O capabilities) of interest to communication
   service providers and M2M service providers, independent of vertical
   markets, such as smart grid, connected cars, e-health, etc.  The
   white paper can be used as a tool to analyze the applicability of
   existing requirements and specifications developed by OMA and other
   cooperative standards development organizations.

A.4.  IPSO Alliance

   IPSO Alliance developed a profile for Device Functions supporting
   devices such as sensors with a limited user interface, where the
   configuration of even basic parameters is impossible to do manually.
   This is a challenge especially for consumer devices that are managed
   by non-professional users.  The configuration of a web service
   application running on a constrained device goes beyond the
   autoconfiguration of the IP stack and local information (e.g. proxy
   address).  Constrained devices need additionally service provider and
   user account related configuration, such as an address/locator and
   the username for a web server.

   IPSO discusses the use cases and requirements for user friendly
   configuration of such information on a constrained device, and
   specifies how IPSO profile Device Function Set can be used in the
   process.  It furthermore defines a standard format for the basic



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   application configuration information.


















































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Appendix B.  Related Research Projects

   o  The EU project IoT-A (Internet-of-Things Architecture) develops an
      architectural reference model together with the definition of an
      initial set of key building blocks.  These enable the integration
      of IoT into the service layer of the Future Internet, and realize
      a novel resolution infrastructure, as well as a network
      infrastructure that allows the seamless communication flow between
      IoT devices and services.  The development includes a conceptual
      model of a smart object as well as a basic Internet of Things
      reference model defining the interaction and communication between
      IoT devices and relevant entities.  The requirements document
      includes also network and information management requirements (see
      [EU-IOT-A]).

   o  The EU project SENSEI specified the document on 'End to End
      Networking and Management' for Wireless Sensor and Actuator
      Networks.  This report presents several research results carried
      out in SENSEI's tasks related to End-to-End Networking and
      Management.  Particular analyses have been addressed related to
      naming and addressing of resources, management of resources,
      resource plug and play, resource level mobility and traffic
      modelling.  The detailed analysis on each of these topics is
      intended to identify possible gaps between their specific
      mechanisms and the functional requirements in the SENSEI reference
      architecture (see [EU-SENSEI]).

   o  The EU project FI-WARE is developing the Things Management GE
      (generic enabler), which uses a data model derived from the OMA DM
      NGSI data model.  Using the abstraction level of things which
      include non-technical things like rooms, places and people, Things
      Management GE aims to discover and look up IoT resources that can
      provide information about things or actuate on these things.  The
      system aimes to manage the dynamic associations between IoT
      resources and things in order to allow internal components as well
      as external applications to interact with the system using the
      thing abstraction as the core concept (see [EU-FI-WARE]).

   o  EU project BUTLER Smart Life discusses different IoT management
      aspects and collects requirements for smart life use cases (e.g.
      smart home or smart city) mainly from service management pov. (see
      [EU-IOT-BUTLER]).









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Appendix C.  Open issues

   o  Section 4 on the management requirements, as the core section in
      the document, needs further discussion and consolidation.















































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Appendix D.  Change Log

D.1.  02-03

   o  Extended the terminology section and removed some of the
      terminology addressed in the new LWIG terminology draft.
      Referenced the LWIG terminology draft.

   o  Moved Section 1.3. on Constrained Device Classes to the new LWIG
      terminology draft.

   o  Class of networks considering the different type of radio and
      communication technologies in use and dimensions extended.

   o  Extended the Problem Statement in Section 2. following the
      requirements listed in Section 4.

   o  Following requirements, which belong together and can be realized
      with similar or same kind of solutions, have been merged.

      *  Distributed Management and Peer Configuration,

      *  Device status monitoring and Neighbor-monitoring,

      *  Passive Monitoring and Reactive Monitoring,

      *  Event-driven self-management - Self-healing and Periodic self-
         management,

      *  Authentication of management systems and Authentication of
         managed devices,

      *  Access control on devices and Access control on management
         systems,

      *  Management of Energy Resources and Data models for energy
         management,

      *  Software distribution (group-based firmware update) and Group-
         based provisioning.

   o  Deleted the empty section on the gaps in network management
      standards, as it will be written in a separate draft.

   o  Added links to mentioned external pages.

   o  Added text on OMA M2M Device Classification in appendix.




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D.2.  01-02

   o  Extended the terminology section.

   o  Added additional text for the use cases concerning deployment
      type, network topology in use, network size, network capabilities,
      radio technology, etc.

   o  Added examples for device classes in a use case.

   o  Added additional text provided by Cao Zhen (China Mobile) for
      Mobile Applications and by Peter van der Stok for Building
      Automation.

   o  Added the new use cases 'Advanced Metering Infrastructure' and
      'MANET Concept of Operations in Military'.

   o  Added the section 'Managing the Constrainedness of a Device or
      Network' discussing the needs of very constrained devices.

   o  Added a note that the requirements in Section 4 need to be seen as
      standalone requirements and the current document does not
      recommend any profile of requirements.

   o  Added Section 4 on the detailed requirements on constrained
      management matched to management tasks like fault, monitoring,
      configuration management, Security and Access Control, Energy
      Management, etc.

   o  Solved nits and added references.

   o  Added Appendix A on the related development in other bodies.

   o  Added Appendix B on the work in related research projects.

D.3.  00-01

   o  Splitted the section on 'Networks of Constrained Devices' into the
      sections 'Network Topology Options' and 'Management Topology
      Options'.

   o  Added the use case 'Community Network Applications' and 'Mobile
      Applications'.

   o  Provided a Contributors section.

   o  Extended the section on 'Medical Applications'.




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   o  Solved nits and added references.


















































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Authors' Addresses

   Mehmet Ersue (editor)
   Nokia Siemens Networks

   Email: mehmet.ersue@nsn.com


   Dan Romascanu (editor)
   Avaya

   Email: dromasca@avaya.com


   Juergen Schoenwaelder (editor)
   Jacobs University Bremen

   Email: j.schoenwaelder@jacobs-university.de

































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