What Is the NIC on My Laptop?

The NICs on a laptop are not separate cards, but are integrated on the motherboard.

In the early days of personal computer networking the network interface card was always a real card that plugged into a motherboard slot in a computer. For the most part, this is no longer the case, as most NICs are integrated on the motherboard. This is especially true for laptops, where space is at a premium, and there is no room inside for a separate card. The NIC in any computer, when configured properly, connects the computer to the local area network and facilitates communication with other networked devices.

Networks

Computer networks facilitate communications between computing devices, including computers, printers and network switches. Ethernet, which is currently the most common network topology deployed, has specific characteristics. Some of these characteristics are the maximum size of a data packet, the speed of the network and the IP addressing scheme. Network equipment is configured to match the local network requirements. Individual computers and other user devices must also be configured properly to connect to the network.

NICs

The network interface card is where network-oriented software and hardware meet. Each NIC must be configured to match the network's characteristics or the card will not be able to connect to the network. The NIC is where the "protocol stack" loads and where the physical wire is interfaced to the computer. Desktops and servers typically include a network interface on the motherboard, but you can install additional NICs in the computer's expansion slots.

Laptop NICs

Modern laptops no longer include a network interface card, since they have a network interface integrated on the motherboard. The connector looks like a larger phone jack with eight wires. Modern laptops also include a wireless network interface, which is invisible to the user, but is commonly the most used interface on a laptop. It is important to know that you can also add a network interface card or a wireless interface card using the PC card slot, which is also included on most modern laptops.

NIC Functions

The network interface card facilitates physical connectivity to the network. It reads frames that are passed to it and examines them for the destination address. If the current interface is the destination, then the packet is processed and passed on to the computer. Otherwise, the packet is ignored. The NIC also accepts data from the computer and frames it for sending out on the network. The network interface is essentially the network gatekeeper for a laptop, managing the traffic in and out of the machine.

References

• Knowledge Systems Institute: Lesson 2 -- The Network Interface Card
• "Guide to Networking Essentials"; Greg Tomsho, et al; 2007