Network interface cards facilitate communication between your computer and the LAN.
Network interfaces are now included in most computers, either integrated onto the motherboard or included as a board in an expansion slot. Either way, network connectivity is built into virtually all new computers. Network interfaces are designed to connect the computer to the local area network, so that the computer can transmit and receive data through the network. To do this, an network interface card (NIC) must perform several functions.
Network Models
The OSI internetworking model uses seven layers to map out the functionality required for computer-to-computer network communication. These layers are, from bottom to top, Physical, Data Link, Network, Transport, Session, Presentation and Application. These seven layers are compressed to four layers in the Internet model and the NIC works at the Network Access layer, which maps to the Physical and Data Link layers of the OSI model.
Network Interface Cards
A network interface card is a meeting place for hardware and software. The NIC communicates with the protocol stack software that defines the rules for the given network's topology. The interface also physically connects to the network through a patch cable or wireless signal. The NIC provides communication from the network to the computer, and vice versa.
Physical Connection
The NIC provides physical connectivity to the network through some medium, whether a twisted-pair patch cable, or a wireless signal in the air, or some other medium. The interface must be equipped with the port for a physical medium, or a wireless transceiver for wireless connections. Typically the only part of the interface that is visible for wired connections is the jack that receives the patch cable connector.
Data Transformation
Network interfaces must bridge the gap between the network and the computer, which entails some data transformation along the way. The computer communicates with the NIC with parallel data streams. This means that the bits flow into the interface along multiple paths simultaneously. On the other hand, the bits must flow onto the network in a serial, or one-at-a-time, format. The NIC has to do the transformation on the data in both directions, providing serial bits to the network, and parallel bits to the computer.
Tags: Network interfaces, patch cable, cable wireless, cable wireless signal, communicates with