What is port number? How is it Work?
What is port number? How is it Work? A network port is a process-specific or an application-specific software construct serving as a communication endpoint, which is used by the Transport Layer protocols of Internet Protocol suite, such as User Diagram Protocol (UDP) and Transmission Control Protocol (TCP).
A specific network port is identified by its number commonly referred to as port number, the IP address in which the port is associated with and the type of transport protocol used for the communication.
A port number is a 16-bit unsigned integer that ranges from 0 to 65535.
What is port number
A port number is a way to identify a specific process to which an Internet or other network message is to be forwarded when it arrives at a server. For the Transmission Control Protocol and the User Datagram Protocol, a port number is a 16-bit integer that is put in the header appended to a message unit.
Port numbers are generally divided into three ranges:
1. The Well Known ports: 0 to 1023
2. The Registered ports: 1024 to 49151
3. The Dynamic and/or Private ports: 49152 to 65535
How Port Numbers Work
Port numbers relate to network addressing. In TCP/IP networking, both TCP and UDPutilize their own set of ports that work together with IP addresses.
These port numbers work like telephone extensions. Just as a business telephone switchboard can use a main phone number and assign each employee an extension number (like x100, x101, etc.), so a computer has a main address and a set of port numbers to handle incoming and outgoing connections.
In both TCP and UDP, port numbers start at 0 and go up to 65535. Numbers in the lower ranges are dedicated to common Internet protocols (like 21 for FTP and 80 for HTTP). To find the specific values used by certain applications, see this TCP / UDP Port Number Glossary. Those using Apple software can also refer to TCP and UDP ports used by Apple software products.