5.6 Telecommunications

---

The telecommunications sector provides voice and data service to public and private users through a public-network infrastructure encompassing the Public Switched Telecommunications Network (PSTN), the Internet, and private enterprise networks. The PSTN provides switched circuits for telephone, data, and leased point-to-point services. It consists of physical facilities, including over 20,000 switches, access tandems, and other equipment. These components are connected by nearly 2 billion miles of fiber and copper cable. The physical PSTN remains the backbone of the infrastructure, with cellular, microwave, and satellite technologies providing extended gateways to the wireline network for mobile users.

The Internet consists of a global network of packet-switched networks that use a common suite of protocols. Internet Service Providers (ISPs) provide end users with access to the Internet. Larger ISPs use Network Operation Centers (NOCs) to manage their high-capacity networks, linking them through Internet peering points or network access points. Smaller ISPs usually lease their long-haul transmission capacity from the larger ISPs and provide regional and local Internet access to end users via the PSTN. Internet access providers interconnect with the PSTN through points.

Supporting the underlying PSTN and ISPs are operations, administration, maintenance, and provisioning systems, which provide the vital management and administrative functions, such as billing, accounting, configuration, and security management. Table 5.6 shows security initiatives in telecommunications.

Initiatives

Define an appropriate threshold for security.

Expand infrastructure diverse routing capability.

Understand the risks associated with vulnerabilities of the telecommunications infrastructure.

Coordinate with key allies and trading partners.

---