Internet Engineering Task Force Hal Folts INTERNET DRAFT National Communications System Expires April 22, 2002 October 22, 2001 Emergency Telecommunications Service in Next-Generation Networks Status of This Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet Drafts. 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 in other than as "work in progress." The list of current Internet-Drafts can be accessed a http://www.ietf.org/ietf/lid-abstracts.text The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Copyright Copyright (c) Internet Society 2001. All rights reserved. Reproduction or translation of the complete documents, but not of extracts, including this notice, if freely permitted. Abstract This white paper presents the functional requirements, features, and objectives for the Emergency Telecommunications Service (ETS) in Next-Generation Networks. The ETS is an extension of the International Emergency Preference Scheme (EIPS) of the ITU-T Recommendation E.106 [1] and includes additional provisions for multimedia services through an Internet-based telecommunications environment. Efforts are underway in the national standards bodies and International organizations to establish a comprehensive family of ETS standards for next-generation networks. This Internet-Draft supersedes an earlier Internet-Draft [2]. 1. Introduction Hal Folts 1 Emergency Telecommunications Service in Next-Generation Networks The purpose of the Emergency Telecommunications Service (ETS) is to facilitate emergency recovery operations for restoring the community infrastructure and for returning the population to normal living conditions after serious disasters and events, such as floods, earthquakes, terrorist attacks, and hurricanes. The ETS will be provided through shared resources from the public telecommunications infrastructure that is evolving from a basic circuit-switched configuration of today's conventional telephone networks to an Internet-based, packet-switched technology providing a richness of communication capabilities. The timely establishment of effective ETS capabilities has been given significant urgency as a result of the 9/11 terrorist attacks in the United States. Many challenges and considerations need to be addressed in defining and establishing the functional capabilities for the ETS in the next generation of packet-based telecommunications services. This paper presents an overview of the basic requirements, features, and concepts for ETS that next-generation telecommunication networks and third-generation (3G) mobile networks are capable of providing and that must receive attention during the process of the convergence of these technologies. Specific solutions are not offered, but this paper is intended to stimulate innovative thinking and productive discussion in industry standards bodies leading to development, establishment, and deployment of appropriate standards for the next generation of telecommunications services. Disaster situations can occur any time, any place unexpectedly. These events often significantly damage the community infrastructure and severely disrupt daily living. Recovery requires rapid response by local authorities, immediate reaction from utility service providers, and support from medical, construction, fire, and police resources. Effective communications are essential to facilitate the myriad activities for coordinating lifesaving activities concurrent with reestablishing control in the disaster area. Following a disaster, immediate response operations focus on saving lives, protecting property, and meeting basic human needs. 2. ETS Operational Requirements Public telecommunication services are universally available, deployed by a massive infrastructure throughout most nations, except in the most remote and unpopulated regions. These critical telecommunications resources, therefore, must be depended upon by the emergency responders for supporting the organization and coordination of initial, as well as ongoing, recovery activities. It is readily possible to realize these capabilities by leveraging the resources that are ubiquitous and most likely to be immediately available any place, any time. This includes the use of wireless services as mobile networks expand their coverage. Dedicated or special government telecommunications resources, on the other hand, do not generally have the immediate global reach to be responsive initially to disaster events. Hal Folts Document - Expires April 22, 2002 2 Emergency Telecommunications Service in Next-Generation Networks Two Recommendations of the International Telecommunication Union, Telecommunication Standardization Sector (ITU-T) present the basic requirements for international emergency telecommunications. ITU-T Recommendation E.106, Description of an International Emergency Preference Scheme [1], applies to telephony services provided by the Public Switched Telephone Network (PSTN), Integrated Services Digital Network (ISDN), and Public Land Mobile Network (PLMN). ITU-T Draft Recommendation F.706, Service Description for an International Emergency Multimedia Service (IEMS) [3], applies to all modes of telecommunications service, including telephony, over the next generation of telecommunication networks, including the packet-based Internet Protocol (IP) technology and 3G mobile networks. The ETS can be used both in national and international contexts and includes the provisions of the IEPS and the IEMS. Conventional circuit-switched wire line telecommunications services are rapidly evolving to a connectionless packet-switched technology. Wireless technology is also evolving toward the new 3G capabilities for seamless provisioning of services over and across the heterogeneous fixed and mobile networks. A substantial transition period is underway as these technologies converge. As a result, there will be many critical issues of transition and interoperability to address. The newly emerging technologies will provide greatly enhanced capabilities that can be leveraged and can benefit emergency recovery operations during serious disaster situations. The Internet- based packet technology provides a very new environment that must be leveraged for providing effective and economical public telecommunications services for supporting ETS capabilities. When a disaster event strikes, the public telecommunications infrastructure generally sustains damage, experiences excessive traffic loads, and is subject to external interference that may severely limit the ability for response and recovery activities to communicate. Therefore, special provisions to facilitate effective communications for the emergency activities are necessary. This includes priority establishment and processing of communications through the telecommunication resources that remain available. ETS traffic needs to receive preferential use of the surviving capacity of the impacted network. 3. ETS Features and Objectives A fully comprehensive ETS needs to have a richness of capabilities to support a variety of operational requirements for emergency recovery forces. The following is a list of specific features that could potentially facilitate communications for disaster recovery activities: A- Selection of multimedia and telephony services B- Rapid authentication of authorized ETS users C- Security protection of ETS traffic D- Preferential access to telecommunications facilities E- Preferential establishment of ETS communications Hal Folts Document - Expires April 22, 2002 3 Emergency Telecommunications Service in Next-Generation Networks F- Preferential routing of ETS traffic G- Preferential use of remaining operational resources for ETS traffic H- Preferential completion of ETS traffic to destination I- Optional preemption of nonemergency traffic J- Allowable degradation of service quality for ETS traffic, as infrastructure resources become unavailable K- Interchange of critical telecommunications service management information Not all of these features may be immediately possible, practical, or available universally. This list focuses on the basic capabilities that need to be addressed and developed. These capabilities could greatly facilitate effective and timely recovery operations during emergency events. This paper will discuss these features in detail. Many nations do not have any emergency capability today except for their public telecommunications infrastructure in its present state without any of the special features listed above. In the United States, the Government Emergency Telecommunications Service (GETS) supports emergency recovery operations. However, it only provides priority establishment and routing of telephone calls through the public switched telephone network (PSTN) for specifically authorized users who expect to be involved in emergency recovery operations. GETS fulfills the basic functional requirements of ITU-T Recommendation E.106. The ETS also has international aspects. Disaster situations are often regional and involve multiple nations. In these cases, disaster recovery assets from multiple nations may be necessary to respond to one specific event. Also, in the increasingly "global" world, many nations often provide support for recovery operations for emergency disasters contained within the borders of another country. ETS traffic, therefore, needs to receive favorable treatment at international gateways and within national networks providing an ETS. The emergence of new telecommunications technologies and their application for telecommunication services in the next generation of networks provides great promise for the realization of an enhanced, comprehensive, and effective global ETS. ITU-T Draft Recommendation F.706 presents requirements for multimedia services to support emergency operations. Not only will voice telephony services need to continue, the inclusion of broadband services like video broadcast and conferencing will also be beneficial. In addition, narrowband capabilities such as Email and instant messaging would facilitate short, rapid command and control information interchange, and would enhance recovery operations. This will be particularly useful during periods of limited bandwidth availability and as a last resort to communicate when conditions become most severe. Currently, prominent international standards bodies are developing a new telecommunication infrastructure that is expected to be deployed over the next several years. It is imperative that the specifications Hal Folts Document - Expires April 22, 2002 4 Emergency Telecommunications Service in Next-Generation Networks of these networks include support for the functional requirements of a comprehensive ETS before equipment and systems are designed, manufactured, and deployed. With the necessary features built into the telecommunications infrastructure, the ETS can then be readily available for emergency response through execution of service level agreements (SLAs) between service customers (SCs) of supporting recovery operations and the telecommunications service providers (SPs). It will then be possible to offer the service more expediently and to avoid the expense of deploying special capabilities or retrofitting existing systems. The SC will then pay the appropriate tariffs for actual services received. The availability of the ETS for authorized users could also be specified in an SLA. The ETS could be always available for use at any time and at any place in a specific network. This would allow fast- response access immediately when the disaster strikes. Some networks, on the other hand, may only activate the ETS upon declaration of an emergency by the appropriate authority. This could cause a serious delay in the ability for response and recovery forces to communicate effectively. Some in between capability could also be possible, where a basic preferential service would always be available and then enhanced features could be activated upon declaration of an emergency. The transition to packet-based and 3G mobile services for next- generation networks will involve a number of issues, one of which is to ensure orderly and transparent continuance of the basic E.106 emergency preference capabilities. During the convergence period, the different schemes for interworking between the two technologies must be considered. For example, voice calls from the telephone or mobile network may transit voice-over-IP links and then terminate in either the telephone network or directly in a packet-based network. The European Telecommunications Standards Institute (ETSI) describes four different scenarios of interoperation [ETSI TR 101 300, V1.1.5, Description of Technical Issues]. Because of the variety in configurations, it is necessary to establish the interfaces for interworking between the signalling systems of today's telephone networks and the new call control and signalling protocols of next- generation networks. This needs to be accomplished without negatively impacting the fundamental operation or infrastructure of Internet- based networks. As new networks with the basic emergency service priority capabilities come into being, it will be important to provide enhanced services by leveraging the new capabilities of packet-based next-generation networks. As indicated earlier, ubiquitous telecommunications resources that provide services to the general population provide the basis for readily available capabilities for an ETS. Because they are at hand, emergency operations activities do not have to wait for deployment of special facilities. However, as emergency operations get underway, supplemental capabilities could also be of significant benefit, particularly when public telecommunication resources become seriously stressed and limited. Therefore, it would be desirable to have a telecommunications infrastructure that is integrated with Hal Folts Document - Expires April 22, 2002 5 Emergency Telecommunications Service in Next-Generation Networks transportable, redeployable, and fully mobile facilities, such as personal communications service, cellular, satellite, and high frequency radio. Interoperability and interfaces among selected government or private facilities, systems, and networks would be very beneficial. It is also highly desirable that ETS resources be as robust as possible to support surviving users under a broad range of circumstances, including widespread damage during natural or man-made disasters. 4 ETS Considerations There are a number of important considerations that need to be studied in order to best use the connectionless packet technology for the ETS in next-generation networks. The advantages and inherent characteristics of the Internet-based technology need to be leveraged and not impeded. It may be necessary to define and establish the appropriate quality, availability, and reliability of service guidelines for the various modes of multimedia communications. There are many formidable challenges that need to be addressed in the fulfillment of the functional requirements that have been established in ITU-T Recommendations E.106 and F.706. They serve as the principal objectives to meet in provisioning a truly comprehensive and effective ETS. More specific considerations in seeking the necessary mechanisms and solutions for ETS are: A- Selection of multimedia and telephony services - The basic service E.106 addresses is telephony as provided by the public switched telephone networks (PSTN), integrated services digital networks (ISDN), and public land mobile networks (PLMN). The emergence of integrated voice/data services of next-generation and 3G mobile networks, based on packet switching technology, need to not only support telephony services but provide a variety of enhanced modes of communication including Email, instant messaging, web and database access, video, and teleconferencing. These additional services can also be used for emergency communications. This will enable emergency recovery operations to have a comprehensive menu of supporting communication capabilities. B- Rapid authentication of authorized ETS users - The ETS is intended for use by only authorized users involved with emergency recovery operations. The appropriate authority of each nation or community would authorize these designated users. Upon initiation of an emergency communication request, an authentication process needs to verify the user's identity to protect the telecommunication resources against excessive use and abuse during an emergency situation. In the United States, a personal identification number (PIN) similar to the application of credit card calling in the PSTN currently authenticates authorized GETS users. For the future ETS, it is desirable to establish an innovative method for a streamlined rapid user authentication in the next-generation and 3G mobile networks. The passing of authentication as the ETS Hal Folts Document - Expires April 22, 2002 6 Emergency Telecommunications Service in Next-Generation Networks communication travels across networks also needs to be addressed. C- Security protection of ETS traffic - Security is a major concern with the evolution of next-generation networks. In addition to the many basic security provisions already under consideration, ETS has additional security provisions that require special attention. Security protection is necessary to prevent unauthorized users from accessing scarce resources needed to support emergency operations. This includes such threats as spoofing, intrusion, and denial of service. In addition, the identity and location of certain authorized users of the ETS need protection. D- Preferential access to telecommunications facilities - There are a number of ways to access telecommunication resources for obtaining ETS capabilities. These include PSTN wire line, wireless, satellite, cable, digital subscriber line (DSL), and optical fiber. There will be a significant advantage for an emergency operations user to be able to obtain access to these various telecommunications services on a priority or preferential basis. This will enable more rapid initiation of emergency communications. Today the PSTN service has no general provision for signalling priority access requests. However, specially marked lines or specifically provisioned "off-hook" services could provide preferential access, but that would only be by line and location and not per ETS request. There is currently no provision for conveying a priority dial tone or service initiation via general access from a conventional telephone instrument. Dial tone comes on a demand basis from a limited selection of ports and heavy traffic conditions can delay access if demand consumes the supply of ports. Therefore, a provision for preferential access to services in next- generation networks is a capability that requires consideration. As with the PSTN dial-tone ports, cellular services have a limited number of channels in each cell to accept call initiation from an end device. When a disaster event occurs in a particular local area, floods of call attempts generally occur. This severely reduces the probability of access. Therefore, a priority access service for designated users or end devices is also needed for cellular services. Appropriate technical mechanisms inherent in the infrastructure need to be applied to enable preferential access via the various methods for initiation of ETS communications. It is imperative that authorized emergency operations have the ability to respond rapidly to disaster events in a timely and efficient manner. Hal Folts Document - Expires April 22, 2002 7 Emergency Telecommunications Service in Next-Generation Networks E- Preferential establishment of ETS communications - A communication may consist of a single unit of information transiting from source to destination or of a flow of information via a series of packets or stream of data. In technologies that support connection mode operation, an end- to-end path for the communication to transit is established upon entry of the address, or telephone number, of the destination terminal. In connectionless mode operation, individual packets may transit the network over different paths. When the total communication involves a series of packets, they are assembled and processed together at the destination. Emergency communications must have a high degree of assurance for successfully reaching the destination, regardless of the networks they transit. Therefore, the ETS traffic needs to be uniquely identified and receive preferential treatment over nonemergency traffic. This provides a priority service for authorized communications in the ETS. In a PSTN, once a connection is established, the call effectively is "hard- wired" in the form of a circuit-switched connection and does not require continuance of preferential status. In a connectionless packet network environment, however, it is necessary to maintain the ETS identification for all respective packets. ETS identification also needs to be conveyed to each of the transit networks, regardless whether they support ETS. Telecommunication service providers (SP) must be able to identify and prioritize emergency communications according to their service level agreement with the service customer (SC). F- Preferential routing of ETS traffic - Routing of packets is a continuing process for an instance of communication until the session has reached completion. As indicated above, the priority status and identification of emergency communications must be maintained until session termination. If the path being followed becomes congested or fails, the network or application layer mechanisms could be applied to dynamically reroute ETS traffic through remaining operational resources. While additional delay may result from the rerouting process, ETS traffic will still have a higher probability of reaching its destination. G- Preferential use of remaining operational resources for ETS traffic- During disaster events infrastructure damage and heavy traffic demand can severely limit public telecommunications. Therefore, ETS traffic needs to have preferential use of the appropriate amount of operational infrastructure required to effectively support recovery operations without impeding the inherent traffic flow throughout the connectionless network. To this end, a scheme of preferential treatment needs to be defined that will accommodate various types of priority services for authorized users as well as for general public emergency use (i.e. Hal Folts Document - Expires April 22, 2002 8 Emergency Telecommunications Service in Next-Generation Networks 911/999/112 emergency calling service). The appropriate balance of traffic flow needs to be maintained to ensure support of emergency traffic while the remaining capacity can be used for other applications. H- Preferential completion of ETS traffic to destination - In addition to considering the issue of preferential establishment, routing, and maintaining an ETS communication, it is also necessary to establish provisions to facilitate completion of the emergency communication to the destination terminal. When the end terminal can handle multiple sessions, its inherent packet-multiplexing feature naturally allows the incoming ETS communication to be delivered. When the terminal device can only handle a single session, such as a cell phone, the user needs to receive an overriding indication of an incoming ETS communication. The destination could then suspend nonemergency communications to free bandwidth for the incoming emergency communication. If preemption were an option, nonemergency communications to the destination could be terminated. Should the destination have "call forwarding" initiated, the network should then continue to reroute and process the emergency communication with preferential treatment to the new destination. I- Optional preemption of nonemergency traffic -ITU-T draft Recommendation F.706 identifies the process and concept of preemption of non-emergency traffic by ETS traffic. While the concept of preemption typically applies to circuit-oriented communications, its application in connectionless network services, if determined viable, needs to be studied and defined. The basic ETS provisions do not include the concept of preemption of nonemergency traffic to free bandwidth and resources for emergency traffic. The intent is to have ETS traffic receive basically preferential treatment. If the communication encounters congestion or a blockage, it should be rerouted if possible. Any nonemergency communication in progress is normally allowed to continue until completion. However, some nations or private networks may allow preemption of nonemergency traffic to enable processing of emergency communications. Therefore, in these cases preemption may be allowed only as an option, which could be invoked as specifically prescribed by that authority. J- Allowable degradation of service quality for ETS traffic, as infrastructure resources become unavailable - Different modes of operation define various levels of quality of service (QoS). Each mode may have multiple classes from the very best QoS to lesser levels. The QoS for different modes of service for the ETS would typically be designated as the best available to ensure clear clean communications and conveyance of important information. However, when the telecommunication resources are experiencing severe stress, an allowable degradation of QoS could be acceptable. This could occur only when resources have become unavailable to the point that the Hal Folts Document - Expires April 22, 2002 9 Emergency Telecommunications Service in Next-Generation Networks network cannot support nonemergency traffic and sufficient bandwidth and resources are not available to support the normally acceptable QoS level for emergency traffic. Rather than lose the ability to communicate, emergency operations need to continue to convey critical information, even if with difficulty. Any possibility of getting information through is better than none at all. The ETS needs to continue operation when only "best effort" service is available. Therefore a special or supplemental class of QoS for ETS is necessary to define the conditions and terms for allowable degradation of service. K- Interchange of critical telecommunications service management information - During emergency operations, interaction between the SCs and SPs through sharing of critical information related to availability and status of telecommunication resources would be beneficial. SCs could maintain knowledge of service availability and could provide reports to SPs of service problems and failures. SCs could also have control of resource configurations in meeting the operational needs at hand. SPs would be able to provide reports of status and availability of resources, failure points, recovery notices, and alerts of lost capabilities. When the ETS is only turned on during a declared emergency, the SC can directly notify the SP on-line to activate the ETS service for the area impacted. An effective service management interface and a simple data interchange mechanism are needed to provide this important capability. 5. Conclusion The establishment of meaningful standards to make ETS a reality requires dedicated cooperation and collaboration among industry and government. Initial ETS capabilities, as defined by ITU-T Recommendation E.106 [1] exist in some nations today and can be deployed in the basic telephone systems that are in place. The evolution of telecommunications technology to provide more effective, efficient, and economical facilities provides both a challenge in transition and an opportunity to apply greatly enhanced capabilities for a national and international ETS. The many aspects, presented in this paper, must receive attention in the international standardization process. Establishment of a comprehensive ETS internationally is multidimensional, including not only the technical issues, but the policy, legal, regulatory, and operational considerations as well. Carlberg presents a technical framework of requirements and proposals for IETF consideration in another Internet Draft [4]. Close cooperation between government and industry will lead to timely establishment of meaningful standards and deployment of ETS capabilities in next-generation and 3G mobile networks. This document is intended to serve as a basis for discussions and development of innovative ideas in standards bodies. The material presented will be further refined as a result of continuing work Hal Folts Document - Expires April 22, 2002 10 Emergency Telecommunications Service in Next-Generation Networks toward establishing a family of comprehensive standards for national and international Emergency Telecommunications Services. Please visit www.iepscheme.net and subscribe to the IEPS Email list to track the progress of work. 6. Security Considerations Ian Brown in another ID presents security considerations for ETS [5]. 7. Acknowledgements Many thanks to Fred Baker, Scott Bradner, Ian Brown, Ken Carlberg, Sean Donelan, Jack Garrity, Stu Goldman, Kimberly King, Gary Thom, Jean Trakinat, and Toby Trygar, for their comments on this draft. 8. Author's Address Hal Folts, Senior Systems Engineer Priority Services - Internet Team, Technology and Programs National Communications System foltsh@ncs.gov +1 703 607-6186 8. References 1. ITU-T, "Description of an International Emergency Preference Scheme", ITU-T Recommendation E.106, March 2000. 2. Folts, H., and Ohno, H, " draft-folts-ohno-IEPS- considerations-00.txt, June 2000. 3. ITU-T, "Service Definition of an International Emergency Multimedia Service", ITU-T Draft Recommendation F.706, August 2001. 4. Carlberg, K, and Brown, I, "Framework for Supporting IEPS in IP Telephony", Internet Draft, draft-carlberg-IEPS-Framework- 01.txt, July 2001 5. Brown, I, "Securing prioritised emergency traffic", Internet Draft, draft-brown-ieps-sec-00.txt, July 2001. 10. 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