port number

What is Port Number (in computer networking)?

A 16-bit integer assigned to a port on a TCP/IP host that enables the host to communicate with another host on the network. Ports can have numbers between 0 and 65,536 and are divided into two types:

• Well-known port numbers, which are fixed numbers between 0 and 1023 and are assigned by the Internet Assigned Numbers Authority (IANA). Some of these numbers are currently unassigned or reserved for future use.
• Dynamically assigned port numbers, which the operating system assigns as needed when a TCP/IP application or service requests a port. These numbers are between 1024 and 65,536 and can be released and reassigned as needed.

See also:

• well-known port numbers