Short for Network Driver Interface Specification, a Windows device driver interface that enables a single network interface card (NIC) to support multiple network protocols. For example, with NDIS a single NIC can support both TCP/IP and IPX connections. NDIS can also be used by some ISDN adapters.
NDIS includes a protocol manager that accepts requests from the network driver (at the transport layer) and passes these requests to the NIC (at the data link layer). So multiple NDIS-conforming network drivers can co-exist. Also, if a computer contains multiple NICs because it is connected to more than one network, NDIS can route traffic to the correct card.