In telecommunications, the term network interface device (NID) is interchangable with network interface unit (NIU)
Meanings of the term
A network interface device can refer to the following ideas:
- NIU/NIDs serve as the point of demarcation between the local exchange carrier network and the customer's premise. NIDs are required at the MPOE (minimum point of entry) which is typically in the basement, first floor telco room, garage, or even outside the building. NIUs are multi-functional devices, which include a protector block to prevent high-voltage surges from affecting premise equipment and inside wiring. It also usually allows the carrier to initiate a loop-test back from the central office to test the integrity of the local loop.
- A device that performs interface functions, such as code conversion, protocol conversion, and buffering, required for communications to and from a network.
- 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.
An NID converts each device protocol into a common transmission protocol.
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.
References
Source: from Federal Standard 1037C