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In communications technology, digital communication at the rate of 64,000 bits per second or lower.


  1. An interconnected group of nodes.
  2. A series of points, nodes, or stations connected by communications channels; the collection of equipment through which connections are made between data stations.

Network Layer

A layer in the OSI reference model. The network layer provides address resolution and routing protocols. Address resolution enables the network layer to determine a unique network address for a node. Routing protocols allow data to flow between networks and reach their proper destination. Examples of network layer protocols are Address Resolution Protocol (ARP), Datagram Delivery Protocol (DDP), Internet Control Message Protocol (ICMP), Interior Gateway Protocol (IGP), Internet Protocol (IP), Internetwork Packet Exchange (IPX) and Packet Layer Protocol (PLP).


Network Interface Card
The hardware communication interface (circuit board) required for the DTE (workstation, PC) to access the network.


A point of interconnection to a network.


Non-Return to Zero
A binary encoding scheme representing ones and zeroes by opposite and alternating high and low voltages, in which there is no return to a zero (reference) voltage between encoded bits.


Non-Return to Zero Inverted
A binary encoding scheme which inverts the signal 1 and leaves the signal unchanged or a 0. Also called transition coding.