network interface device (NID)

1. A device that performs interface functions, such as code conversion, protocol conversion, and buffering, required for communications to and from a network. 2. A device used primarily within a local area network (LAN) to allow a number of independent devices, with varying protocols, to communicate with each other. Note 1: An NID converts each device protocol into a common transmission protocol. Note 2: The transmission protocol may be chosen to accommodate directly a number of the devices used within the network without the need for protocol conversion for those devices by the NID. Synonym network interface unit. 3. Regulatory term of key importance to telephone companies. There is a physical point and a device where the telephone network terminates and the customer premises network begins. Sometimes this is simply a passive device, and sometimes this is a powered device. For a typical FTTP network, the ONT is at the NID. For a typical early stage FTTN network, the NID is simply a passive device at the side of the house and the VDSL signal actually continues into the house.