February 2002

BY RAVI RAVISHANKAR

It will take years to fully assess the impact of the events of Sept. 11, 2001. However, it is already quite clear that as a result of the terrorist attacks, the security of circuit-switched and packet-based telecommunications networks has become a vital national concern. Efforts to ensure the safety and integrity of the telecommunications infrastructure will lead to greater government involvement, which will escalate the implementation of existing regulations, drive the creation of new regulations, lead to greater participation in the development of industry standards.

Enhanced Emergency Services
As rescue workers and families searched for victims of the Sept. 11 attack, the need to identify a calling party�s location was demonstrated dramatically. Basic 911 service provides the ability to deliver the calling party�s number to designated public safety answering points (PSAPs). Enhanced 911 (E911) service actually provides the location of the calling party. The most stringent requirements specify location accuracy to within 50 meters of the handset.

E911 service will potentially be mandated for emerging packet-based networks -- VoDSL, VoCable, and VoIP. However, providing location identification in a packet network creates a challenge. In a VoIP network, how do providers pinpoint the location of a user on a LAN? In addition, the new networks must be compatible with legacy 911 tandem switches and with PSAP equipment. And, the implementation of E911 service will require service providers to maintain and constantly update location databases in the network.

Law Enforcement Surveillance
The 1994 Communications Assistance for Law Enforcement Act (CALEA) requires telecommunications providers to incorporate surveillance technology into their networks. In the wake of September 11, the government is pushing CALEA implementation forward, and it appears that packet telephony will not be exempt. In a Sept. 27th ruling, the FCC denied a request made by the Cellular Telecommunications and Internet Association (CTIA) for a blanket extension of the Sept. 30, 2001 deadline for wireline, cellular, and broadband PCS carriers to implement a packet-mode communications electronic surveillance capability. The FCC mandated that carriers come into compliance or seek individual relief by Nov. 19, 2001. All carriers, including packet telephony carriers, must be fully CALEA compliant by June 30, 2002.

The technical requirements for CALEA implementation are still being identified within the industry. The FCC is accepting input from industry associations and operators in the form of �safe harbor� documents. The Telecommunication Industry Association (TIA) subcommittee TR45.2 developed one such safe harbor document, J-STD-025, popularly known as the J-Standard. A portion of the J-Standard covers packet-mode communication. These requirements were included in the FCC�s November 19 order.

CableLabs filed a similar safe harbor document covering VoCable, and the International Softswitch Consortium (ISC) is currently working on a safe harbor document for the softswitch architecture. These organizations are actively working with the commission on CALEA issues related to the packet telephony industry.

Protecting The Signaling Network
The security and reliability of the public telecommunication infrastructure is receiving greater government scrutiny. There is a general perception that as a result of network convergence, the PSTN is more vulnerable to malicious attacks. Government reports and statements from high-ranking government officials reflect these concerns.

Signaling is critical to all network operations. The PSTN signaling infrastructure is very much a closed network. In today�s voice network, signaling is transported on a separate, dedicated resource to ensure the integrity of call control.

As convergence opens the networks, the security of the signaling messages may be placed at greater risk. In packet networks, both signaling and data can be transported on the same network. Unless a higher QoS is guaranteed for signaling in this shared network, critical services may be severely impacted during network congestion. The use of invalid signaling messages can take trunk groups out of service, prevent resources from being released, direct calls to incorrect destinations, or instruct switches to throttle calls. Therefore, enhanced mediation and firewall capability will be required to protect the network.

Prioritizing Service For Critical Communications
Many government organizations have implemented emergency telecommunication services (ETS) to provide priority communication during crisis situations. In the past, the agencies relied primarily on private networks for emergency communication. However, as the reach of these agencies becomes global, they must rely increasingly on the public telecommunication infrastructure in emergency situations. This reliance will drive new regulations and standards.

In the United States, the Government Emergency Telecommunication Service (GETS) delivers ETS. An important and recently introduced capability of GETS is the high probability of call completion (HPC) feature, which is supported by major local exchange carriers, AT&T, MCI WorldCom, and Sprint. The feature marks emergency call signals as a priority and the network provides preferential treatment without preempting the calls already in progress. Several national governments have recognized the need for such a priority service and have implemented emergency communication services in their own network. International Recommendations E.106, the definition for International Emergency Preparedness Scheme (IEPS), was established by the ITU-T standard organization in March 2000 to provide priority services across national boundaries.

In its June 2001 report, the NSTAC CTF recognized the need for ongoing standards development efforts to support the national security/emergency preparedness (NS/EP) priority requirements in converged networks. The rollout of this service will likely take place in two phases. In the first phase, IP-based voice calls will support PSTN-like priority access and transport transfer. The second phase expands the priority processing to include e-mail, instant messaging, and other multimedia communication. Efforts are under way in both the ITU-T and Internet Engineering Task Force (IETF) to expand and include additional provisions for multimedia services in an IP-based telecommunications network. ITU-T Recommendations F.706 will provide similar framework for the next generation International Emergency Multimedia Service (IEMS).

Following the recent attacks, issues concerning the security of the telecommunications networks have been brought to the forefront. The telecommunications industry will be challenged to take measures to enhance personal and national security by ensuring that the future telecommunication infrastructure is reliable and secure.

Mr. Ravi Ravishankar is director, Advanced Technology Planning, Tekelec. His focus is on defining signaling solutions and products for the next-generation packet telephony and 3G wireless networks. Tekelec is a leading developer of telecommunications signaling infrastructure, softswitches, testing and diagnostic solutions, and service applications. Please visit their Web site at www.tekelec.com.

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