Lesson 2 - Internal Computer Components: CPUs, I/O, Memory, and Accessory Cards

   Network Interface Cards

A NIC (pronounced "nick") is the hardware component inserted into the PC or workstation that provides connectivity to a network. The NIC provides the interface between the physical networking cable and the software implementing the networking protocols. The NIC is responsible for transmitting and receiving information to and from a network.

NIC Connectivity

There are many ways to connect NICs to a network. The NIC Connectivity Diagram shows a NIC that attaches to a network via a twisted pair cable through a wall outlet. On the other side of the wall, the twisted pair cable goes to a punchdown block, a place where cables are often terminated to provide continuing connections to other devices. From the punchdown block, the twisted pair cable is sometimes connected to a hub or Multi-station Access Unit (MAU) that forms the central connecting point of the network.

If the network contains a dedicated server or other communicating device, it also contains a NIC. The Network Interface Card Options Diagram shows characteristics to consider when choosing a NIC.

The NIC fits into an expansion slot on the motherboard's I/O bus. This bus connects adapter cards, such as NICs, to the main CPU and RAM. The speed at which data may be transferred to and from the NIC is determined by the I/O bus bandwirdth, processor speed, NIC design and quality of components, operating system, and the network topology used.

   Activities

See the Activities and Extended Activities section in Unit 1 Lesson 2 in your textbook Introduction to Networking to test what you have learned so far.

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