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Growing Vulnerability of the Public Switched Networks: Implications for the National Security Emergency Preparedness Executive Summary Today it is universally acknowledged that the United States is becoming more and more an information society, and that telecommunications and information networks are essential components of an information society’s supporting infrastructure. Networks of the future will be increasingly relied on for a remarkable variety of voice, data, and video services. It is thus of considerable concern that, because of powerful trends in the evolution of the nation’s telecommunications and information networks, they are becoming more vulnerable to serious interruptions of service. THE EMERGING PROBLEM Specifically, because of changes in regulation, technology, and the interaction between competitive market incentives to cut costs and market-specific customer demand, tomorrow’s networks are at greater risk than today’s. Regulation is opening major portions of the network to customer control; technologies—notably fiber optics, digital switching, and software control—are driving network assets into fewer, but more critical, network nodes; competition is reducing the incentives of providers to build redundancy into their networks; and customer demand is not stimulating deployment of network assets that are sufficiently robust to cover the full range of national security emergency preparedness (NSEP) contingencies.
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Growing Vulnerability of the Public Switched Networks: Implications for the National Security Emergency Preparedness While the National Communications System (NCS) has sponsored several valuable national-level programs to address the ability of the nation’s networks to support NSEP, the committee believes that there is a set of valid NSEP contingencies that fall outside the traditional view of NSEP and that need to be addressed. Because of the growing reliance of our information society on smoothly functioning telecommunications and information networks, NSEP concerns should include provision for reducing network vulnerabilities to broader economic and social dislocations arising from network disruptions. Just how vulnerable our networks have become is illustrated by the experiences of 1988: There were three major switching center outages, a large fiber optic cable cut, and several widely reported invasions of information databases by so-called computer hackers. As we become more dependent on networks, the consequences of network failure become greater and the need to reduce network vulnerabilities increases commensurately. RECOMMENDATIONS The committee makes the following recommendations to reduce growing network vulnerabilities and thus provide adequate assurance that NSEP needs will be fully supported by the nation’s public switched networks. Recommendation No. 1: Assure Sufficient National Level National Security Emergency Preparedness Resources In light of society’s growing reliance on information and telecommunications networks and the resulting increase in risk to national security emergency preparedness, the National Security Council should review whether the resources available to the National Communications System are sufficient to permit it to fulfill its responsibilities for planning, implementing, and administering programs designed to decrease communications vulnerabilities for national security emergency preparedness users in an environment of proliferating public networks. (Chapter 4) Government must be able to analyze what network features are necessary for national security. Government must also be able to implement plans and procure services pertinent to national security needs.
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Growing Vulnerability of the Public Switched Networks: Implications for the National Security Emergency Preparedness In its efforts to date to assure the NSEP capabilities of the public networks the federal government has not sufficiently considered how network capabilities might be enhanced to reduce vulnerabilities to broader economic and social disruption. There is a gap in NSEP oversight: Our committee believes that the government should review whether its existing resources are sufficient to adequately perform expanded NSEP oversight of the proliferating public networks and clarify the appropriate agency missions to address these broader NSEP questions. Recommendation No. 2: Use More Technology Diversity Because public network evolution is increasingly being driven by economic considerations, the Nationwide Communications System should ask the National Security Telecommunications Advisory Committee to examine how national security emergency preparedness needs can be met; the National Security Telecommunications Advisory Committee should recommend steps to make critical network nodes more secure, reduce concentration of network traffic, and increase alternate route diversity. (Chapter 5) Trends in telecommunications and computer technology are leading toward increased central switch routing capacity, increased traffic concentration, and reduced route diversity. High-capacity central office digital switches are already concentrating network traffic at key central network nodes. Virtually all the network trunking capacity will be provided by optical fiber, thus greatly increasing traffic concentration. As optical fibers replace dozens of copper wires or microwave links and as fiber becomes increasingly the transmission medium of choice, network route diversity will be greatly diminished. Worrisome trends in network technology go beyond loss of route diversity. Network control intelligence is migrating from switching systems into common channel signaling systems. This separated signaling network will be very thin, relying on a small number of large databases; traffic on interexchange networks will be switched via a limited number of signal transfer points, greatly increasing network vulnerability, especially to coordinated attacks on critical network nodes.
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Growing Vulnerability of the Public Switched Networks: Implications for the National Security Emergency Preparedness Recommendation No. 3: The Nationwide Emergency Telecommunications Service Is Needed Given that there is no assurance that by the year 2000 enhanced routing capabilities will be ubiquitous in the public networks, the Nationwide Emergency Telecommunications Service is needed now, and its functional equivalent will be needed beyond the year 2000 for national security emergency preparedness purposes. (Chapter 5) Emerging network capabilities will not provide a substitute for NCS’s proposed Nationwide Emergency Telecommunications Service (NETS). Among key new network capabilities the committee examined were the integrated services digital networks (ISDN), switching techniques that use the asynchronous transfer mode, Federal Telecommunications System 2000, and the widespread deployment of very small aperture terminals (VSATs). Neither these nor any other foreseeable emerging technology will, by themselves, ensure adequate fulfillment of the requirements for the proposed NETS. The public networks will lack sufficient capability to provide NSEP unless NETS is deployed. Recommendation No. 4: Provide Priority Service As emergency services cannot be provided without prepositioning dedicated network equipment, the National Communications System should ask the Federal Communications Commission to require the industry to deploy the network assets needed to provide priority service for selected users during declared emergencies. (Chapter 4) Major emergency situations cause overload conditions on the telephone system. These overloads will indiscriminately block calls of emergency personnel who need communications access as well as nonessential callers. Thus, priority service provisions for such selected users as police, firemen, hospitals, and government officials are necessary. Service options should include such techniques as priority dial tone and trunk access, for example. The committee understands that ample authority already exists for the government to require that industry be permitted to deploy network assets that would support priority service under a
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Growing Vulnerability of the Public Switched Networks: Implications for the National Security Emergency Preparedness wide range of contingencies. However, without emplacement of adequate network assets in advance, it will not be possible to implement priority plans quickly in event of a crisis. Recommendation No. 5: Provide Additional Redundancy Because concentration of network traffic and routing nodes is increasing network vulnerability, additional route diversity and network node diversity should be provided for national security emergency preparedness purposes. (Chapter 5 ) Implementing priority access procedures cannot alone ensure the availability of emergency communications. If fire destroys the only central switching office that can route emergency traffic from a given area, or if an earthquake uproots critical optical fiber transmission lines, essential communication linkages will be severed. The increased reliance of the public networks upon a single technology for transmission—optical fiber—is thus a source of great risk to NSEP. These measures will cost money. However, whether users, shareholders, or taxpayers should bear the cost is a matter of public policy that goes beyond the scope of the committee’s charter. Recommendation No. 6: Increase Radio Access Capabilities Since radio technologies can provide a valuable source of alternative routing in emergencies, the National Communications System should consider how terrestrial and satellite radio transmission can be employed to provide route diversity for national security emergency preparedness purposes; in particular, consideration should be given as to how very small aperture terminals can be used to back up the public switched networks. (Chapter 5) Advances in radio technology offer great promise for augmenting network route diversity. Cellular mobile radio has enormously expanded available capacity for mobile communications interconnected with the landline switched networks; digital microwave technology is making telephone service economical in hitherto inaccessible rural areas; VSATs are making data distribution by satellite economical and efficient and offer possibilities for economical deployment of widely distributed intelligent network signaling architectures.
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Growing Vulnerability of the Public Switched Networks: Implications for the National Security Emergency Preparedness Recommendation No. 7: Establish Emergency Plans As crisis management skills are critical in making emergency assets work effectively, the National Communications System should establish additional emergency plans, tailored to the evolving public networks, that use simulated disaster and recovery scenarios to develop fallback strategies for network use during emergencies. (Chapter 4) Preparedness requires more than availability of adequate facilities. Emergency personnel must be trained to use the equipment with the speed and efficiency needed to enable adequate discharge of NSEP responsibilities. Large organizations must develop procedures and practice their implementation, adjusting plans as experience with actual disasters dictates. In this regard, experience with recent disasters will help provide a blueprint for developing future contingency plans. Finally, as a truly practical endeavor the NCS should commission the analysis of scenarios that postulate the destruction of a megaswitch and enumerate the steps that would be currently undertaken to restore communications along with the problems that would likely be encountered. These should include estimates of costs, time required to restore communication, the level of the restoration, telecommunications service priority adherence, and network management obstacles. Recommendation No. 8: Establish Software Security Measures Since the public networks are increasingly driven by software, the National Communications System should consider how to protect the public network from penetration by hostile users, especially with regard to harmful manipulation of any software embedded within the public networks that is open to customer access for purposes of network management and control. (Chapter 7) Perhaps the most disturbing of the growing network vulnerabilities is that of contemplated open outside access to network executable code and databases. The desire to open access to the public networks must be counterbalanced by a recognition that the integrity of the public networks must be protected. The growing number of mischievous and hostile penetrations of networked computer systems portends
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Growing Vulnerability of the Public Switched Networks: Implications for the National Security Emergency Preparedness the possibility of similar penetrations of network switching databases, even though the executable code may be thought to be well protected. Recommendation No. 9: Exploit Value-Added Networks Because packet switching techniques are well suited for adaptive routing, the National Communications System should devise ways to exploit the capabilities of the commercial packet-switched, value-added data networks for national security emergency preparedness purposes, including message transmission, electronic mail boxes, and more robust signaling. (Chapter 6) Another potentially valuable source of public network redundancy is value-added networks. Whereas today’s circuit-switched networks were designed almost exclusively to carry voice transmission, the network of the future will be increasingly driven by data transmission needs. A class of networks known as value-added networks (VANs), first introduced in the 1970s, is becoming widely deployed for commercial use. These networks are packet switched rather than circuit switched, that is, they do not tie up a circuit end-to-end, but occupy space only when data are actually being transmitted. VANs offer valuable network routing capabilities if interconnected with the public switched networks. Such signaling capability is superbly suited to alternate routing schemes: Packet switching was originally designed to enable adaptive routing through damaged networks. The committee also notes, however, that making use of VANs to strengthen survivability will only succeed if the other recommendations covering attention to greater redundancy are followed. Recommendation No. 10: Promote Internetwork Gateways Because interconnection of the proliferating public networks is essential for national security emergency preparedness, the National Communications System should explore how the capabilities of public and private institutional voice and data networks can be used to provide redundancy; particular attention should be given to how network interoperability can be increased through deployment of gateway architectures. (Chapter 6)
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Growing Vulnerability of the Public Switched Networks: Implications for the National Security Emergency Preparedness Many large government and commercial private networks are not currently fully interoperable with the public switched networks: They operate according to a different set of protocols and standards. These networks, if fully interconnected with the public networks, could augment NSEP resources. Another impediment to end-to-end interconnectivity is the possibility that many terminal devices will not be entirely compatible with network interface standards. Recommendation No. 11: Retain Existing Synchronization As existing network synchronization levels already exceed those required for national security emergency preparedness, no action need be taken to increase the robustness of network synchronization beyond existing standards for normal network operation; designers of terminal devices should engineer them to operate satisfactorily under system synchronization standards. (Chapter 5) In one respect, that of network synchronization, the existing and prospective network capabilities appear more than sufficient to meet present and future NSEP requirements. The committee examined network synchronization in detail and concluded that the present standards ensure an adequate margin of safety. However, because users have full freedom to connect registered terminal devices to the public networks, it is incumbent upon equipment designers to build units that function properly within existing network synchronization standards. * * * * In essence, the vulnerabilities stemming from changes in network regulation, technology, competition, and customer demand are not significantly offset by any countertrend. Robust systems such as NETS will be necessary to enable the government to carry out vital NSEP responsibilities. Civil emergencies will also require enhancements and backup to the capabilities of networks whose architectures are being driven primarily by economic incentives rather than by security concerns. Otherwise, serious losses will threaten governmental, commercial, and personal pursuits.
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