Data Transmission

-In modern networks, data are transferred using packet switching.

-Messages are broken into units called packets, and sent from one computer to the other.

-At the destination, data are extracted from one or more packets and used to reconstruct the original message.

-Each packet has a maximum size, and consists of a header and a data area.

-The header contains the addresses of the source and destination computers and sequencing information necessary to reassemble the message at the destination.