Networks are very fast, but there is a limit to the amount of traffic networks can transport at one time. The solution to this problem is to break this traffic into small pieces known as data packets.
A data packet, also called a packet, is a very small part of the entire piece of data that needs to be sent.
data packet Data that consist of three parts—a header, the data itself, and a trailer.
A cyclical redundancy check (CRC) is performed at the sending and receiving computers to make sure the data packet arrived with no errors.
cyclical redundancy check (CRC) Error checking used in networks. A sending node performs a mathematical calculation on the packet and the result is attached to the packet’s trailer. The receiving node performs the same calculation on the packet it received. If the calculations differ, the CRC signals the source computer to retransmit the packet.
The job to neatly chunk, address, and deliver the information in a network is handled by the network interface card (NIC) in each computer.
The NIC does the following:
Provides the source, or hardware, address of the computer.
Prepares the data from the computer for the network cable.
Sends data to another computer.
Controls the flow of data between the computer and the cabling.
Receives incoming data from another computer.
Translates electrical impulses from the cable into binary code that the computer understands.
Within the computer itself, information travels along pathways known as buses. A bus consists of multiple “lanes” (wires) set side by side. bus A data pathway that connects components in a computer using parallel cabling or wire.
Data packets travel in parallel transmission within the computer, but in serial transmission on a cable.
Data on a network move from the “multilane” computer cable to a “single-lane” network cable.
parallel transmission The orderly procession of transmitted data in computers in which groups of bits are transferred simultaneously side by side over two or more wires.
serial transmission The procession of transmitted data in which bits are sent over network cables and travel bit by bit one at a time.