Management of Networks with Constrained Devices: Use Cases
draft-ietf-opsawg-coman-use-cases-01
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 7548.
|
|
|---|---|---|---|
| Authors | Mehmet Ersue , Dan Romascanu , Jürgen Schönwälder , Anuj Sehgal | ||
| Last updated | 2014-02-14 | ||
| Replaces | draft-ersue-opsawg-coman-use-cases | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Formats | |||
| Reviews | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 7548 (Informational) | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-ietf-opsawg-coman-use-cases-01
Internet Engineering Task Force M. Ersue, Ed.
Internet-Draft Nokia Solutions and Networks
Intended status: Informational D. Romascanu
Expires: August 18, 2014 Avaya
J. Schoenwaelder
A. Sehgal
Jacobs University Bremen
February 14, 2014
Management of Networks with Constrained Devices: Use Cases
draft-ietf-opsawg-coman-use-cases-01
Abstract
This document discusses the use cases concerning the management of
networks, where constrained devices are involved. A problem
statement, deployment options and the requirements on the networks
with constrained devices can be found in the companion document on
"Management of Networks with Constrained Devices: Problem Statement
and Requirements".
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 18, 2014.
Copyright Notice
Copyright (c) 2014 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
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
Ersue, et al. Expires August 18, 2014 [Page 1]
Internet-Draft Constrained Management: Use Cases February 2014
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Access Technologies . . . . . . . . . . . . . . . . . . . . . 5
2.1. Constrained Access Technologies . . . . . . . . . . . . . 5
2.2. Mobile Access Technologies . . . . . . . . . . . . . . . . 5
3. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1. Environmental Monitoring . . . . . . . . . . . . . . . . . 7
3.2. Infrastructure Monitoring . . . . . . . . . . . . . . . . 7
3.3. Industrial Applications . . . . . . . . . . . . . . . . . 8
3.4. Energy Management . . . . . . . . . . . . . . . . . . . . 10
3.5. Medical Applications . . . . . . . . . . . . . . . . . . . 12
3.6. Building Automation . . . . . . . . . . . . . . . . . . . 13
3.7. Home Automation . . . . . . . . . . . . . . . . . . . . . 15
3.8. Transport Applications . . . . . . . . . . . . . . . . . . 15
3.9. Vehicular Networks . . . . . . . . . . . . . . . . . . . . 17
3.10. Community Network Applications . . . . . . . . . . . . . . 18
3.11. Military Operations . . . . . . . . . . . . . . . . . . . 19
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
5. Security Considerations . . . . . . . . . . . . . . . . . . . 22
6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 23
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 24
8. Informative References . . . . . . . . . . . . . . . . . . . . 25
Appendix A. Open Issues . . . . . . . . . . . . . . . . . . . . . 26
Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 27
B.1. draft-ietf-opsawg-coman-use-cases-00 -
draft-ietf-opsawg-coman-use-cases-01 . . . . . . . . . . . 27
B.2. draft-ersue-constrained-mgmt-03 -
draft-ersue-opsawg-coman-use-cases-00 . . . . . . . . . . 27
B.3. draft-ersue-constrained-mgmt-02-03 . . . . . . . . . . . . 27
B.4. draft-ersue-constrained-mgmt-01-02 . . . . . . . . . . . . 28
B.5. draft-ersue-constrained-mgmt-00-01 . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 30
Ersue, et al. Expires August 18, 2014 [Page 2]
Internet-Draft Constrained Management: Use Cases February 2014
1. Introduction
Small devices with limited CPU, memory, and power resources, so
called constrained devices (aka. sensor, smart object, or smart
device) can be connected to 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.
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
type of challenges compared to the management of a traditional IP
network.
This document aims to understand the use cases for the management of
a network, where constrained devices are involved. The document
lists and discusses diverse use cases for the management from the
network as well as from the application point of view. The
application scenarios discussed aim to show where networks of
constrained devices are expected to be deployed. For each
application scenario, we first briefly describe the characteristics
followed by a discussion on 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.
A problem statement, deployment and management topology options as
well as the requirements on the networks with constrained devices can
be found in the companion document [COM-REQ].
This documents builds on the terminology defined in
[I-D.ietf-lwig-terminology] and [COM-REQ].
Ersue, et al. Expires August 18, 2014 [Page 3]
Internet-Draft Constrained Management: Use Cases February 2014
[I-D.ietf-lwig-terminology] is a base document for the terminology
concerning constrained devices and constrained networks. Some use
cases specific to IPv6 over Low-Power Wireless Personal Area Networks
(6LoWPANs) can be found in [RFC6568].
Ersue, et al. Expires August 18, 2014 [Page 4]
Internet-Draft Constrained Management: Use Cases February 2014
2. Access Technologies
Besides the management requirements imposed by the different use
cases, the access technologies used by constrained devices can impose
restrictions and requirements upon the Network Management System
(NMS) and protocol of choice.
It is possible that some networks of constrained devices might
utilize traditional non-constrained access technologies for network
access, e.g., local area networks with plenty of capacity. In such
scenarios, the constrainedness of the device presents special
management restrictions and requirements rather than the access
technology utilized.
However, in other situations constrained or mobile access
technologies might be used for network access, thereby causing
management restrictions and requirements to arise as a result of the
underlying access technologies.
2.1. Constrained Access Technologies
Due to resource restrictions, embedded devices deployed as sensors
and actuators in the various use cases utilize low-power low data-
rate wireless access technologies such as IEEE 802.15.4, DECT ULE or
BT-LE for network connectivity.
In such scenarios, it is important for the NMS to be aware of the
restrictions imposed by these access technologies to efficiently
manage these constrained devices. Specifically, such low-power low
data-rate access technologies typically have small frame sizes. So
it would be important for the NMS and management protocol of choice
to craft packets in a way that avoids fragmentation and reassembly of
packets since this can use valuable memory on constrained devices.
Devices using such access technologies might operate via a gateway
that translates between these access technologies and more
traditional Internet protocols. A hierarchical approach to device
management in such a situation might be useful, wherein the gateway
device is in-charge of devices connected to it, while the NMS
conducts management operations only to the gateway.
2.2. Mobile Access Technologies
Machine to machine (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. Different
applications, e.g., in a home appliance or in-car network, use
Ersue, et al. Expires August 18, 2014 [Page 5]
Internet-Draft Constrained Management: Use Cases February 2014
Bluetooth, Wi-Fi or Zigbee locally 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:
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
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 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.
Ersue, et al. Expires August 18, 2014 [Page 6]
Internet-Draft Constrained Management: Use Cases February 2014
3. Use Cases
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. 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
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.
Ersue, et al. Expires August 18, 2014 [Page 7]
Internet-Draft Constrained Management: Use Cases February 2014
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.
3.3. Industrial Applications
Industrial Applications and smart manufacturing refer to tasks such
as networked control and monitoring of manufacturing equipment, asset
and situation management, or manufacturing process control. 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 demands, 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.
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
Ersue, et al. Expires August 18, 2014 [Page 8]
Internet-Draft Constrained Management: Use Cases February 2014
energy optimization.
Management of Industrial Applications and smart manufacturing may in
some situations involve Building Automation tasks such as control of
energy, HVAC (heating, ventilation, and air conditioning), lighting,
or access control. Interacting with management systems from other
application areas might be important in some cases (e.g.,
environmental monitoring for electric energy production, energy
management for dynamically scaling manufacturing, vehicular networks
for mobile asset tracking).
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.
Ersue, et al. Expires August 18, 2014 [Page 9]
Internet-Draft Constrained Management: Use Cases February 2014
3.4. Energy Management
The EMAN working group developed an energy management framework
[I-D.ietf-eman-framework] for devices and device components 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. The EMAN requirements document [RFC6988]
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 the Smart Grid. A Smart
Grid is an electrical grid that uses data networks to gather and to
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. A
Smart Grid provides sustainable and reliable generation,
transmission, distribution, storage and consumption of electrical
energy based on advanced energy and information technology. Smart
Grids enable the 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.
Ersue, et al. Expires August 18, 2014 [Page 10]
Internet-Draft Constrained Management: Use Cases February 2014
Smart Metering is a good example of Smart Grid based Energy
Management applications. Different types of possibly wireless small
meters produce all together a large amount of data, which is
collected by a central entity and processed by an application server,
which may be located within the customer's residence or off-site in a
data-center. The communication infrastructure can be provided by a
mobile network operator as the meters in urban areas will have most
likely a cellular or WiMAX radio. In case the application server is
located within the residence, such meters are more likely to use WiFi
protocols to interconnect with an existing network.
An AMI network is another example of the Smart Grid that enables an
electric utility to retrieve frequent electric usage data from each
electric meter installed at a customer's home or business. This is
unlike Smart Metering, in which case the customer or their agents
install appliance level meters, because an AMI infrastructure is
typically managed by the utility providers. 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.
Each meter in the AMI network typically contains constrained devices
of the C2 type. Each meter uses the constrained devices to connect
to mesh networks 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. Usage data
and outage notifications can be sent by these meters to the utility's
headend systems, typically located in a data center managed by the
utility, which include meter data collection systems, meter data
management systems, and outage management systems.
Meters in an AMI network, unlike in Smart Metering, act as traffic
sources and routers as well. Typically, 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 for
example, larger amounts of traffic might flow downstream while
smaller amounts flow upstream. The mesh network is anchored by a
collection of higher-end devices that bridge the constrained network
with a backhaul link that connects to a less-constrained network via
cellular, WiMAX, or Ethernet. These higher-end devices might be
installed on utility poles that could be owned and managed by a
different entity than the utility company.
Ersue, et al. Expires August 18, 2014 [Page 11]
Internet-Draft Constrained Management: Use Cases February 2014
While a Smart Metering solution is likely to have a smaller number of
devices within a single household, AMI network installations could
contain 1000 meters per router, i.e., the higher-end device. Meters
in a local network that use a specific router form a Local Meter
Network (LMN). When powered on, meters discover nearby LMNs, select
the optimal LMN to join, and the meters in that LMN to route through.
However, in a Smart Metering application the meters are likely to
connect directly to a less-constrained network, thereby not needing
to form such local mesh networks.
Encryption key sharing in both types of network is also likely to be
important for providing confidentiality for all data traffic. In AMI
networks the 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.
Smart Metering solution could adopt a similar approach or the
security may be implied due to the encrypted WiFi networks they
become part of.
These examples demonstrate that the Smart Grid, and Energy Management
in general, 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) 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). 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 such a network requires end-to-end management of
and information exchange through different types of networks.
However, as of today there is no integrated energy management
approach and no common information model available. Specific energy
management applications or network islands use their own management
mechanisms.
3.5. 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
Ersue, et al. Expires August 18, 2014 [Page 12]
Internet-Draft Constrained Management: Use Cases February 2014
losing orientation. Fitness and wellness applications, such as
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.
3.6. 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 the devices are expected to be managed assets and
Ersue, et al. Expires August 18, 2014 [Page 13]
Internet-Draft Constrained Management: Use Cases February 2014
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
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
Ersue, et al. Expires August 18, 2014 [Page 14]
Internet-Draft Constrained Management: Use Cases February 2014
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.
3.7. Home Automation
Home automation includes the control of lighting, heating,
ventilation, air conditioning, appliances, entertainment and home
security devices to improve convenience, comfort, energy efficiency,
and security. It can be seen as a residential extension of building
automation. However, unlike a building automation system, the
infrastructure in a home is operated in a considerably more ad-hoc
manner, with no centralized management system akin to a Building
Automation System (BAS) available.
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, by third party
home automation service providers (e.g., small specialized companies
or home automation device manufacturers) or by residents by using the
application user interface provided by home automation devices 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 services providers 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 and/or third parties providing
management of home automation solutions as a service. A varying
combination of electricians, service providers or the residents may
be responsible for different aspects of managing the infrastructure.
The time scale for failure detection and resolution is in many cases
likely counted in hours to days.
3.8. 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
Ersue, et al. Expires August 18, 2014 [Page 15]
Internet-Draft Constrained Management: Use Cases February 2014
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
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.
Ersue, et al. Expires August 18, 2014 [Page 16]
Internet-Draft Constrained Management: Use Cases February 2014
3.9. Vehicular Networks
Networks involving mobile nodes, especially transport vehicles, are
emerging. Such networks are used to provide inter-vehicle
communication services, or even tracking of mobile assets, to develop
intelligent transportation systems and drivers and passengers
assistance services. Constrained devices are deployed within a
larger single entity, the vehicle, and must be individually managed.
Vehicles can be either private, belonging to individuals or private
companies, or public transportation. Scenarios consisting of
vehicle-to-vehicle ad-hoc networks, a wired backbone with wireless
last hops, and hybrid vehicle-to-road communications are expected to
be common.
Besides the access control and security, depending on the type of
vehicle and service being provided, it would be important for a NMS
to be able to function with different architectures, since different
manufacturers might have their own proprietary systems.
Unlike some mobile networks, most vehicular networks are expected to
have specific patterns in the mobility of the nodes. Such patterns
could possibly be exploited, managed and monitored by the NMS.
The challenges in the management of vehicles in a mobile application
are manifold. Firstly, the issues caused through the device mobility
need to be taken into consideration. The up-to-date position of each
node in the network should be reported to the corresponding
management entities, since the nodes could be moving within or
roaming between different networks. Secondly, a variety of
troubleshooting information, including sensitive location
information, needs to be reported to the management system in order
to provide accurate service to the customer.
The NMS must also be able to handle partitioned networks, which would
arise due to the dynamic nature of traffic resulting in large inter-
vehicle gaps in sparsely populated scenarios. Constant changes in
topology must also be contended with.
Auto-configuration of nodes in a vehicular network remains a
challenge since based on location, and access network, the vehicle
might have different configurations that must be obtained from its
management system. Operating configuration updates, while in remote
networks also needs to be considered in the design of a network
management system."
Ersue, et al. Expires August 18, 2014 [Page 17]
Internet-Draft Constrained Management: Use Cases February 2014
3.10. 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.
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
Ersue, et al. Expires August 18, 2014 [Page 18]
Internet-Draft Constrained Management: Use Cases February 2014
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, 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
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 network management station 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.
3.11. Military Operations
The challenges of configuration and monitoring of networks faced by
military agencies can be different from the other use cases since the
requirements and operating conditions of military networks are quite
different.
With technology advancements, military networks nowadays have become
Ersue, et al. Expires August 18, 2014 [Page 19]
Internet-Draft Constrained Management: Use Cases February 2014
large and consist of varieties of different types of equipment that
run different protocols and tools that obviously increase complexity
of the tactical networks. In many scenarios, configurations are,
most likely, manually performed. Furthermore, some legacy and even
modern devices do not even support IP networking. Majority of
protocols and tools developed by vendors that are being used are
proprietary which makes integration more difficult.
The main reason for this disjoint operation scenario is that most
military equipment is developed with specific tasks requirements in
mind, rather than interoperability of the varied equipment types.
For example, the operating conditions experienced by high altitude
equipment is significantly different from that used in desert
conditions and interoperation of tactical equipment with
telecommunication equipment was not an expected outcome.
Currently, most military networks operate with a fixed Network
Operations Center (NOC) that physically manages the configuration and
evaluation of all field devices. Once configured, the devices might
be deployed in fixed or mobile scenarios. Any configuration changes
required would need to be appropriately encrypted and authenticated
to prevent unauthorized access.
Hierarchical management of devices is a common requirement of
military operations as well since local managers may need to respond
to changing conditions within their platoon, regiment, brigade,
division or corps. The level of configuration management available
at each hierarchy must also be closely governed.
Since most military networks operate in hostile environments, a high
failure rate and disconnection rate should be tolerated by the NMS,
which must also be able to deal with multiple gateways and disjoint
management protocols.
Multi-national military operations are becoming increasingly common,
requiring the interoperation of a diverse set of equipment designed
with different operating conditions in mind. Furthermore, different
militaries are likely to have a different set of standards, best
practices, rules and regulation, and implementation approaches that
may contradict or conflict with each other. The NMS should be able
to detect these and handle them in an acceptable manner, which may
require human intervention.
Ersue, et al. Expires August 18, 2014 [Page 20]
Internet-Draft Constrained Management: Use Cases February 2014
4. 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.
Ersue, et al. Expires August 18, 2014 [Page 21]
Internet-Draft Constrained Management: Use Cases February 2014
5. Security Considerations
In several use cases, constrained devices are deployed in unsafe
environments, where attackers can gain physical access to the
devices. As a consequence, it is crucial to properly protect any
security credentials that may be stored on the device (e.g., by using
hardware protection mechanisms). Furthermore, it is important that
any credentials leeking from a single device do not simplify the
attack on other (similar) devices. In particular, security
credentials should never be shared.
Since constrained devices often have limited computational resources,
care should be taken in choosing efficient but cryptographically
strong crytographic algorithms. Designers of constrained devices
that have a long expected lifetime need to ensure that cryptographic
algorithms can be updated once devices have been deployed. The
ability to perform secure firmware and software updates is an
important management requirement.
Several use cases generate sensitive data or require the processing
of sensitive data. It is therefore an important requirement to
properly protect access to the data in order to protect the privacy
of humans using Internet-enabled devices. For certain types of data,
protection during the transmission over the network may not be
sufficient and methods should be investigated that provide protection
of data while it is cached or stored (e.g., when using a store-and-
forward transport mechanism).
Ersue, et al. Expires August 18, 2014 [Page 22]
Internet-Draft Constrained Management: Use Cases February 2014
6. Contributors
Following persons made significant contributions to and reviewed this
document:
o Ulrich Herberg (Fujitsu Laboratories of America) contributed the
Section 3.10 on Community Network Applications.
o Peter van der Stok contributed to Section 3.6 on Building
Automation.
o Zhen Cao contributed to Section 2.2 Mobile Access Technologies.
o Gilman Tolle contributed the Section 3.4 on Automated Metering
Infrastructure.
o James Nguyen and Ulrich Herberg contributed to Section 3.11 on
Military operations.
Ersue, et al. Expires August 18, 2014 [Page 23]
Internet-Draft Constrained Management: Use Cases February 2014
7. Acknowledgments
Following persons reviewed and provided valuable comments to
different versions of this document:
Dominique Barthel, Carsten Bormann, Zhen Cao, Benoit Claise, Bert
Greevenbosch, Ulrich Herberg, James Nguyen, Zach Shelby, and Peter
van der Stok.
The editors would like to thank the reviewers and the participants on
the Coman maillist for their valuable contributions and comments.
Ersue, et al. Expires August 18, 2014 [Page 24]
Internet-Draft Constrained Management: Use Cases February 2014
8. Informative References
[RFC6130] Clausen, T., Dearlove, C., and J. Dean, "Mobile Ad Hoc
Network (MANET) Neighborhood Discovery Protocol (NHDP)",
RFC 6130, April 2011.
[RFC6568] Kim, E., Kaspar, D., and JP. Vasseur, "Design and
Application Spaces for IPv6 over Low-Power Wireless
Personal Area Networks (6LoWPANs)", RFC 6568, April 2012.
[RFC6779] Herberg, U., Cole, R., and I. Chakeres, "Definition of
Managed Objects for the Neighborhood Discovery Protocol",
RFC 6779, October 2012.
[RFC6988] Quittek, J., Chandramouli, M., Winter, R., Dietz, T., and
B. Claise, "Requirements for Energy Management", RFC 6988,
September 2013.
[I-D.ietf-lwig-terminology]
Bormann, C., Ersue, M., and A. Keranen, "Terminology for
Constrained Node Networks", draft-ietf-lwig-terminology-07
(work in progress), February 2014.
[I-D.ietf-eman-framework]
Claise, B., Schoening, B., and J. Quittek, "Energy
Management Framework", draft-ietf-eman-framework-15 (work
in progress), February 2014.
[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-olsrv2-19 (work in progress), March 2013.
[COM-REQ] Ersue, M., "Constrained Management: Problem statement and
Requirements", draft-ietf-opsawg-coman-probstate-reqs
(work in progress), January 2014.
Ersue, et al. Expires August 18, 2014 [Page 25]
Internet-Draft Constrained Management: Use Cases February 2014
Appendix A. Open Issues
o Section 3.11 should be replaced by a different use case motivating
similar requirements or perhaps deleted if the IETF prefers to not
work on specific requirements coming from military use cases.
o Section 3.8 and Section 3.9 should be merged.
Ersue, et al. Expires August 18, 2014 [Page 26]
Internet-Draft Constrained Management: Use Cases February 2014
Appendix B. Change Log
B.1. draft-ietf-opsawg-coman-use-cases-00 -
draft-ietf-opsawg-coman-use-cases-01
o Reordered some use cases to improve the flow.
o Added "Vehicular Networks".
o Shortened the Military Operations use case.
o Started adding substance to the security considerations section.
B.2. draft-ersue-constrained-mgmt-03 -
draft-ersue-opsawg-coman-use-cases-00
o Reduced the terminology section for terminology addressed in the
LWIG and Coman Requirements drafts. Referenced the other drafts.
o Checked and aligned all terminology against the LWIG terminology
draft.
o Spent some effort to resolve the intersection between the
Industrial Application, Home Automation and Building Automation
use cases.
o Moved section section 3. Use Cases from the companion document
[COM-REQ] to this draft.
o Reformulation of some text parts for more clarity.
B.3. draft-ersue-constrained-mgmt-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.
Ersue, et al. Expires August 18, 2014 [Page 27]
Internet-Draft Constrained Management: Use Cases February 2014
* 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.
B.4. draft-ersue-constrained-mgmt-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.
Ersue, et al. Expires August 18, 2014 [Page 28]
Internet-Draft Constrained Management: Use Cases February 2014
o Added a note that the requirements in [COM-REQ] need to be seen as
standalone requirements and the current document does not
recommend any profile of requirements.
o Added a section in [COM-REQ] for 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.
B.5. draft-ersue-constrained-mgmt-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'.
o Solved nits and added references.
Ersue, et al. Expires August 18, 2014 [Page 29]
Internet-Draft Constrained Management: Use Cases February 2014
Authors' Addresses
Mehmet Ersue (editor)
Nokia Solutions and Networks
Email: mehmet.ersue@nsn.com
Dan Romascanu
Avaya
Email: dromasca@avaya.com
Juergen Schoenwaelder
Jacobs University Bremen
Email: j.schoenwaelder@jacobs-university.de
Anuj Sehgal
Jacobs University Bremen
Email: a.sehgal@jacobs-university.de
Ersue, et al. Expires August 18, 2014 [Page 30]