Internet Engineering Task Force Hal Folts INTERNET DRAFT National Communications System Expires August 1, 2002 Februaqry 1, 2002 Emergency Telecommunications Service in Evolving 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 newly emerging telecommunication networks. The ETS is an extension of the International Emergency Preference Scheme (IEPS) of the ITU-T Recommendation E.106 [1] and includes additional provisions for multimedia services through an packet-based telecommunications environment. The preferential features of the ETS will only apply to severe congestion conditions due to extremely high traffic loads and extensive failure of basic infrastructure. ETS is not required under normal operating conditions and when adequate capacity is available to support all traffic. Efforts are underway in the national standards bodies and International organizations to identify, establish, and apply a comprehensive family of ETS standards for new packet-based networks. This Internet-Draft supercedes an earlier Internet-Draft, draft-folts- ohno-ieps-considerations-00.txt> [2] 1. Introduction The purpose of the Emergency Telecommunications Service (ETS) is to facilitate emergency recovery operations for restoring the community 1 Emergency Telecom. Service December 2001 infrastructure and for returning the population to normal living conditions after serious disasters and events, such as floods, earthquakes, hurricanes, and terrorist attacks. 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 an effective ETS has been given significant urgency as a result of the September 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 emerging packet-based telecommunications services. This paper presents an overview of the basic requirements, features, and concepts for ETS that packet-based telecommunication 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 evolving 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 A US Government working group recently identified fourteen basic functional requirements for the future ETS. These requirements are listed in the table below and represent the objectives that need to be fulfilled for national security and emergency preparedness (NS/EP) in the ETS. ================================================================ NS/EP Telecommunication Services Functional Requirements Description ================================================================ a. Enhanced Priority Services supporting NS/EP missions must Treatment be provided priority treatment over other traffic. ---------------------------------------------------------------- b. Secure Networks Networks must have protection against Folts Document, July 2, 2002 2 Emergency Telecom. Service December 2001 corruption of, or unauthorized access to, traffic and control, including expanded encryption techniques and user authentication, as appropriate. --------------------- ----------------------------------------- c. Non-Traceability Selected users must be able to use NS/EP services without risk of usage being traced (i.e., without risk of user or location being identified). --------------------- ----------------------------------------- d. Restorability Should a disruption occur, services must be capable of being reprovisioned, repaired, or restored to required service levels on a priority basis. --------------------- ----------------------------------------- e. International Services must provide access to and Connectivity egress from international carriers. ---------------------------------------------------------------- f. Interoperability Services must interconnect and interoperate with other selected government or private facilities, systems, and networks. --------------------------------------------------------------- g. Mobility The communications infrastructure must support transportable, redeployable, or fully mobile communications (e.g., personal communications service, cellular, satellite, high frequency radio). ---------------------------------------------------------------- h. Ubiquitous Coverage Services must be readily accessible to support the national security leadership and inter- and intra-agency emergency operations, wherever they are located. ---------------------------------------------------------------- i. Survivability/ Services must be robust to support Endurability surviving users under a broad range of circumstances, from the widespread damage of a natural or man-made disaster up to and including nuclear war. ---------------------------------------------------------------- j. Voice Band Service The service must provide voice band service in support of presidential and other communications. ---------------------------------------------------------------- k. Broadband Service The service must provide broadband service in support of NS/EP missions (e.g., video, imaging, web access, multimedia). ---------------------------------------------------------------- l. Scaleable Bandwidth NS/EP users must be able to manage the capacity of the communications services to support variable bandwidth requirements. ---------------------------------------------------------------- Folts Document, July 2, 2002 3 Emergency Telecom. Service December 2001 M. Affordability Services must leverage network capabilities to minimize cost (e.g., use of existing infrastructure, commercial off-the-shelf technologies, services). ---------------------------------------------------------------- n. Reliability/ Services must perform consistently and Availability precisely according to their design requirements and specifications, and must be usable with high confidence. ================================================================ These fourteen functional requirements are discussed in this white paper. Several of these are elaborated upon in more detail in Section 4 providing considerations for the eleven ETS features and objectives. The other requirements are addressed by text presenting the many concepts that are involved in the development of a comprehensive and effective ETS. The /x/ in the text identifies the Functional Requirement in the above table that is being addressed in this paper. 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 possible to realize readily these capabilities by leveraging the resources that are ubiquitous and most likely to be immediately available any place, any time /h/. This includes the use of wireless services as mobile networks expand their coverage /g/. 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. 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 newly emerging 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 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 /f/. The newly emerging Folts Document, July 2, 2002 4 Emergency Telecom. Service December 2001 technologies will provide greatly enhanced capabilities that can be leveraged and can benefit emergency recovery operations during serious disaster situations. The Packet-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 /a/. 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 /j/ /k/ B. Rapid authentication of authorized ETS users /b/ C. Security protection of ETS traffic /b/ /c/ D. Preferential access to telecommunications facilities /a/ E. Preferential establishment of ETS communications /a/ F. Preferential routing of ETS traffic /a/ G. Preferential use of remaining operational resources for ETS traffic /a/ H. Preferential completion of ETS traffic to destination /a/ I. Optional preemption of nonemergency traffic /a/ J. Allowable degradation of service quality for ETS traffic /l/ /n/ K. Interchange of critical telecommunications service management information /d/ /n/ Not all of these features may be immediately possible, practical, or available universally. The above 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 Folts Document, July 2, 2002 5 Emergency Telecom. Service December 2001 regional and involve multiple nations /e/. 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. /a/ The emergence of new telecommunications technologies and their application for telecommunication services in the evolving telecommunication networks provides great promise for the realization of an enhanced, comprehensive, and effective global ETS. ITU-T Draft Recommendation F.706 [3] 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 but also will be beneficial /k/. In addition, narrowband capabilities such as instant messaging and presence as well as Email 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 of these networks include support for the functional requirements of a comprehensive ETS before equipment and systems are designed, manufactured, and deployed. None of these new specifications shall cause change or impairment of operation of existing emergency capabilities or the basic packet-switched infrastructure. With the necessary capabilities built into the new telecommunications infrastructure, the ETS can then become readily available with a diversity of services for emergency response operations through execution of service level agreements (SLAs) between service customers (SCs) 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. /h/ The availability of the ETS for authorized users could also be specified in an SLA. The ETS could always be 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 inbetween 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 new telecommunication services 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 Folts Document, July 2, 2002 6 Emergency Telecom. Service December 2001 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 /f/. The European Telecommunications Standards Institute (ETSI) describes four different scenarios of interoperation [4]. 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 evolving telecommunication networks. This needs to be accomplished without negatively impacting the fundamental operation or infrastructure of existing and future packet-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 the emerging packet-based networks./k/ As indicated earlier, ubiquitous telecommunications resources that provide services to the general population provide the basis for readily available capabilities for an ETS./h/ Since public telecommunication resources are normally 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 can be readily integrated with transportable, redeployable, and fully mobile facilities, such as personal communications service, cellular, satellite, and high frequency radio /f/ /g/. Interoperability and interfaces among selected government or private facilities, systems, and networks would be very beneficial /f/. 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 /i/. 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 the new telecommunication capabilities. The advantages and inherent characteristics of the packet-based technology need to be leveraged and not impeded. It will 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 [1] and F.706 [3]. 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 /k/ - The basic service defined in ITU-T Recommendation E.106 [1] is telephony as provided by the public switched telephone networks (PSTN), integrated services digital networks (ISDN), and public land Folts Document, July 2, 2002 7 Emergency Telecom. Service December 2001 mobile networks (PLMN). The emergence of integrated voice/data services of evolving telecommunication and 3G mobile networks, based on packet switching technology, need to not only support telephony services but also provide a variety of enhanced modes of communication including instant messaging and presence, Email, web and database access, video, and teleconferencing. These additional services can also be used effectively 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 /b/ - The ETS is intended for use only by 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 and rapid user authentication in the emerging telecommunication and 3G mobile networks. The passing of authentication as the ETS communication travels across networks also needs to be addressed. C. Security protection of ETS traffic /b/ /c/- Security is a major concern with the evolution of packet-based 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 /a/ - 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, not per ETS request. There is currently no provision for conveying a priority dial tone or service initiation via general Folts Document, July 2, 2002 8 Emergency Telecom. Service December 2001 access from a conventional telephone instrument. Dial tone comes 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 packet-based telecommunication 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. E. Preferential establishment of ETS communications /a/ - 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) and other SPs. F. Preferential routing of ETS traffic /a/ - 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 Folts Document, July 2, 2002 9 Emergency Telecom. Service December 2001 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 /a/ - 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 packet 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. 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 nonemergency applications. H. Preferential completion of ETS traffic to destination /a/ - 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 an 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 /a/-ITU-T draft Recommendation F.706 [3] 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 packet 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 Folts Document, July 2, 2002 10 Emergency Telecom. Service December 2001 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 /l/ /n/ -Various levels of quality of service (QoS) are defined for different applications and modes of operation. Each may have multiple classes from the very best QoS to lesser levels. The QoS for different ETS services 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 would occur only when resources have become unavailable to the point that the 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 /d/ /n/ - 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 Ps of service problems and failures. SCs could also have a view of resource configurations supporting 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 activated 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. Conclusions 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 /m/ Folts Document, July 2, 2002 11 Emergency Telecom. Service December 2001 facilities in emerging packet-based networks provides both a challenge in transition and an opportunity to apply greatly enhanced capabilities for a national and an international ETS. Many of the ETS requirements addressed in this paper may already be satisfied without change or addition to existing standards. These capabilities need to be identified and their application to the ETS needs to be defined. Where capabilities for ETS do not exist, new standards or additions to existing specifications in the international standardization process needs to be addressed. It is imperative that any specifications include support for the functional requirements of a comprehensive ETS before equipment and systems are designed, manufactured, and deployed. None of these new specifications shall cause change or impairment of operation of existing emergency capabilities or to the basic packet-switched infrastructure. ETS is multidimensional and includes many critical technical issues as well as policy, legal, regulatory, and operational issues that need to be addressed. Close cooperation between government and industry will lead to timely establishment or identification of meaningful standards and deployment of ETS capabilities in the evolving telecommunication 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 toward identifying, establishing, and applying 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, Greg Bain, 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 Folts Document, July 2, 2002 12 Emergency Telecom. Service December 2001 Service", ITU-T Draft Recommendation F.706, August 2001. 4. ETSI TR 101 300, V2.1.1, "Telecommunications and Internet Protocol Harmonization Over Networks (TIPHON); Description of Technical Issues", October 1999 5. Brown, I, "Securing prioritised emergency traffic", Internet Draft, draft-brown-ieps-sec-00.txt, July 2001. 10. Copyright "Copyright (C) The Internet Society (date). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. However, this document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided as an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OR MERCHANTABILITY OR FITNESS FOR A PARTIC Folts Document, July 2, 2002 13