 systems, and scanners to communicate with one another. Moreover, LANs allow multiple devices to share and have access to expensive peripherals such as printers, firewalls, and centralized databases. A LAN is located on an individual organization's premises. LATA (Local Access And Transport Area) Upon divestiture in 1984, LATAs were set up as the areas in which Bell telephone companies were allowed to sell local telephone services. LATAs cover metropolitan statistical areas based on population sizes. For example, Massachusetts has two LATAs and Wisconsin has four, but Wyoming, which has a small population, has one LATA. LATAs are sometimes used for billing telephone calls in the United States. Layer 4 One of the seven layers of the OSI model. Layer 4 is the Transport layer that routes and prioritizes packets, based on the source of the packet, the destination port number, the protocol type, and the application. For example, Layer 4 devices can prioritize voice and video SO that networks using IP for voice and data can handle voice www.TechnicalPDF.com without the delays and lost packets associated with lower-level protocols. LDAP (Lightweight Directory Access Protocol) A directory protocol that describes a uniform way of organizing information in directories. Examples of LDAP directories include the address books in e-mail systems. LDAP enables companies to use one central directory to update multiple corporate directories. They also facilitate single sign-on to access different applications on corporate intranets. leased line Analogous to two tin cans with a string between two or more sites. Organizations that rent leased lines pay a fixed monthly fee for the leased lines that are available exclusively to the organization that leases them. Leased lines can be used to transmit voice, data, or video. They are also called private or dedicated lines. LEC (Local Exchange Carrier) Any company authorized by the state public utility commission to sell local telephone service. local loop The telephone line that runs from