What Is Port In Computer & Network?

What is Port

In computer networking, a port is a communication endpoint. the concept of port numbers was established by the early developers of the ARPANET in informal co-operation of software authors and system administrators.

The term port number was not yet used at this time. this was before the term socket number was used in the early development stages of the network.

Types of Ports

A port can either physical or virtual.

Physical Port

Physical network port allows cables to be connected computers, routers, modems, and other peripheral devices. the different types of physical ports on computer network hardware include.

• Ethernet port - square shaped connection points for ethernet
• USB ports - rectangular shaped connection points for USB cables
• Serial port - round shaped connection points for serial cables.

And many other ports

Common virtual port numbers

Virtual ports are used in UDP (User Datagram Protocol) and TCP (Transfer Control Protocol) to identify unique end-to-end connections. there are 65,535 virtual ports. each one could have different use, depending on the type of data going through them.

• 21 - FTP (File transfer protocol)
• 22 - SSH (Secure Shell)
• 23 - Telnet remote login service
• 25 SMTP (Simple mail transfer protocol)
• 53 - DNS service (Domain name system)
• 80 - HTTP (Hyper text transfer protocol) used in the world wide web
• 110 - POP3 (Post office protocol)
• 119 - NNTP (Network news transfer protocol)
• 123 - NTP (Network time protocol)
• 143 - IMAP (Internet message access protocol)
• 161 - SNMP - (Simple network management protocol)
• 194 - IRC (Internet relay chat)

TCP

TCP stands for Transfer Control Protocol. the TCP provides end-to-end communication. it was developed by U.S. department of defense between the 1970s and 1980s.  it enables information transfer and communication between two computers. they are used to send data securely. the role of TCP is to divide the data into small parts. when sending packets using TCP, the data portion of each packet is formatted as a TCP segment. it can be used for internet applications like WhatsApp, Email.

UDP

UDP stands for User Datagram Protocol. this protocol was designed by David P Reed in 1980. it is defined in RFC 768.

It is a simple transport layer communication protocol. it is a connection-less protocol, meaning when data transfer occurs, this protocol does not establish a connection between the sender and the receiver.

In UDP, the receiver does not generate any acknowledgment for receiving the data and the sender does not generate any acknowledgment of sending the data. it transfer data directly.

UDP does not give guarantee that your data will reach its destination or not. this data can also reach in small quantity and some data packets may also get destroyed in the middle of transmission.

UDP protocol is used to transfer such data where we need more speed than accuracy and reliability because it gives faster service than TCP. it can be used for streaming applications like YouTube.

List of most common ports

https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers