port assignments wikipedia

How Does Internet Work

Tcp and udp port numbers – complete list.

This is a list of Internet socket port numbers used by application communication with TCP and UDP on the Transport Layer of the Internet Protocol Suite for the host-to-host communications.

Let’s see who makes it possible? The Internet Assigned Numbers Authority (IANA) assigns all port numbers except Dynamic or Private ports. IANA is a standards organization in the world that is responsible for assigning various addressing standards.

There are different types of port numbers: Well Known Ports (Numbers 0 to 1023), Registered Ports (Numbers 1024 to 49151) and Dynamic or Private Ports (Numbers 49152 to 65535). The last porn number type  Dynamic or Private Ports  will not appear on our list because they are cannot be registered with IANA. This range is used for custom or temporary purposes and for automatic allocation of ephemeral ports. They are usually assigned dynamically to client applications when initiating a connection. It is not very common for a client to connect to a service using a Dynamic or Private Port, sometimes some peer-to-peer file sharing programs do.

We will introduce the list of the ports with short description of different port types.

Using both TCP and UDP is also normal sometime. Some applications may use both TCP and UDP. For example, the low overhead of UDP with his short header enables DNS to serve many client requests very quickly. However, sending the requested information sometimes may require the reliability of TCP. In that case, the port number of 53 that is a well known port number is used by both protocols with this service.

Let’s see the list of port numbers:

• Well-known ports
• Registered Ports

Well Known Ports (Numbers 0 to 1023) – These numbers are reserved for services and applications. They are commonly used for applications such as HTTP (web server) POP3/SMTP (e-mail server) and Telnet. By defining these well-known ports for server applications, client applications can be programmed to request a connection to that specific port and its associated service.

Registered Ports >> Registered Ports

Registered Ports (Numbers 1024 to 49151) – These port numbers are assigned to user processes or applications. These processes are primarily individual applications that a user has chosen to install rather than common applications that would receive a Well Known Port. When not used for a server resource, these ports may also be used dynamically selected by a client as its source port.

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This is very helpful. Thank you for the information! You may want to change a word in the sentence (The last porn number type Dynamic or Private Ports.).

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Well-Known Port Numbers

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Definition of Well-Known Port Numbers in Network Encyclopedia.

What is Well-known port numbers?

Well-known port numbers are port numbers for Transmission Control Protocol (TCP)  or User Datagram Protocol (UDP)  that have been assigned to specific TCP/IP applications or services by the Internet Assigned Numbers Authority (IANA) . Well-known port numbers are assigned within the range 0 through 1023 and are specified in Request for Comments (RFC) 1060. (The total range of possible port numbers is 0 through 65535.) The following table describes some of the well-known port numbers.

“Registered ports” are port numbers that are not controlled by IANA but that IANA registers to indicate to the Internet community which vendor applications use them. Registered ports range from 1024 through 65535 and can be used by any process or program requesting it if the operating system has not already allocated it for a specific use. Programs and processes that communicate using remote procedure calls (RPCs) often randomly select a registered port for each RPC communication session.

Port Number List