IP Packets

Information travels across the Internet and other networks in small pieces of data called packets. Packets are the basic unit of data transfer on networks. On the Internet these data units are known as IP packets.

Every IP packet contains the information it needs to travel from the source computer from which it originated, to the destination computer to which it will arrive. This is the addressing information required to move from one computer across the Internet to another computer. This address cosists of five pieces of information.

• The address of the destination computer known as the destination IP address.
• The address of the source computer known as the source IP address.
• The number of a port on the destination computer known as the destination port number.
• The number of a port on the source computer known as the source port number.
• The transport protocol associated with this IP packet which is normally TCP.