Layer 2 of the seven-layer Open Systems Interconnection (OSI) protocol model that facilitates the detection of and recovery from transmission errors. A data link connection is built on one or more physical connections.

Data networks is a system that transfers data between network access points (nodes) through data switching, system control and interconnection transmission lines. Data networks are primarily designed to transfer data from one point to one or more points (multipoint). Data networks may be composed of a variety of communication systems including: circuit switches, leased lines and packet switching networks. There are predominately two types of data networks, broadcast and point-to-point.

Devices that combine the functionality of data service units (DSU) and channel service units (CSU) to adapt data from user communication systems to communication lines with multiple channels. The DSU portion as an interface between a customer s data terminal equipment and a data communication network. DSU are the digital equivalent of the analog modem and are translation codecs (COde and DECode) coupled with a network termination interface (NTI). The CSU portion is used to coordinate communication from one or more data terminal equipment (DTE) devices to logical channels on a multi-channel communication circuit.

The User Part in an SS7 message specified for data services.

A collection of data that is interrelated that is stored in memory (disk, computer, or other data storage medium.)

A system that...