Port numbers
In a server, more than one user process can use TCP at the same time. To identify the data associated with each process, port numbers are used. Port numbers are 16-bit, and numbers up to 65535 are possible, although in practice only a small subset of these numbers is commonly used.
Well-known ports are used only to establish communication between client and server processes. After that, the server allocates an ephemeral port number for subsequent use. Ephemeral port numbers are unique port numbers, which are assigned dynamically when processes start communicating. They are released when communication is complete.


What are Port Numbers?
When a computer, phone or other device connects to the Internet it can run several programs.
Each program shares the same Internet connection and they can send and receive different types of data, such as web pages, emails, or instant messages.
So, how does a device know which application it should give each type of data? Because it device uses port numbers to help direct the data it receives to the correct application.
An IP address will ensure the data arrives at your device. Once there, the port number ensures that it gets to the right application.
If you compare IP addresses to a company's phone number; the port number is like an extension you dial (or option you press) that gets you through to the right person or department.

Port numbers are divided into three ranges:
- Well-known ports
- Registered ports
- Ephemeral ports
1. Well-known ports or system ports are from 0 - 1023. The operating system uses them for processes that provide widely used types of network services.
2. Registered ports have numbers from 1024 - 49151. They are for specific services that companies have registered with IANA (The Internet Assigned Numbers Authority oversees Internet Protocol-related symbols and numbers such as IP address allocation, media types, and port numbers.)
3. Ephemeral ports have numbers from 49152-65535, they are used for temporary purposes (such as tabs in a browser) also known as dynamic or private ports. They are used for private, customized services, or for termportary purposes

IMAGES
VIDEO
COMMENTS
To calculate the mass of a specific number of atoms of an element, divide the number of atoms by 6.02 x 1023 and then multiply by the molar mass of the element. The process for calculating mass from the number of atoms is the same for all e...
There is no one port number for a computer. Computers use multiple ports to accommodate different processes running on the computer. The port number in use varies on the software or service being used and the computer’s configuration.
Are you planning a cruise vacation from the beautiful city of Seattle? If so, it’s important to consider your transportation options once you arrive at the Seattle cruise port. Renting a car when arriving at the Seattle cruise port offers n...
Ports with numbers 0–1023 are called system or well-known ports; ports with numbers 1024-49151 are called user or registered ports, and ports with numbers
Port numbers from 0 to 1023 are reserved for common TCP/IP applications and are called well-known ports. The use of well-known ports allows client applications
Ports 0-1023, are assigned to the most universal and accepted TCP/IP standard applications, or applications the IANA expects to become standards.
in the TCP/IP network services database to prevent port number conflicts. Parent
... throughout the Internet, by IANA, the Internet Assigned Numbers Authority. The well-known port numbers are in the range 0 through 1023. Some examples are
Registered ports have numbers from 1024 - 49151. They are for specific services that companies have registered with IANA (The Internet Assigned Numbers
through the proxy server. The proxy server
The well-known ports cover the range of possible port numbers from 0 through 1023. The registered ports are numbered from 1024 through 49151. The remaining
Ports with numbers 0–1023 are called system or well-known ports; ports with numbers 1024-49151 are called user or registered ports, and
Description · Well-known ports range from 0 through 1023. · Registered ports are 1024 to 49151. · Dynamic ports (also called private ports) are
Port 0 to 1023: These TCP/UDP port numbers are considered as well-known ports. These ports are assigned to specific server sevice by the Internet Assigned