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]