What are the TCP/IP Ports and its applications?

Port is a logical address of any protocol or we can call it a dedicated door for each protocol in which all the packets fall in that box. We can also say that the mailbox for each protocol is a box in which each protocol packet is dropped.

Later on the receiver will open that packet and read the content which the sender has sent. Port is a dedicated separate line for packet transmission for each protocol.

TCP is called as Transmission control protocol which provides a communication service between an application program and the Internet protocol (IP)

A port is a number used to uniquely identify a transaction over a network by specifying both the host and the service. Port numbers range from 0 to 65535. The well known ports are 0-1023, registered ports are 1024-49151 and the dynamic ports or private ports are from 49152-65535.

TCP/IP is a suite of communication protocols used to connect hosts on the internet.


A number is assigned to user sessions and server applications in an IP network. The port number resides in the header area of the packet being transmitted.


  • http port number is 80
  • ftp port number is 20, 21
  • email- SMPT (outgoing message)
  • Non-encrypted port number is 25
  • Secure (TLS) port number is 587
  • Secure (SSL) port number is 465
  • POP 3 (Incoming message)
  • Non-encrypted port number is 110
  • Secure (SSL) port number is 995
  • Telnet port number is 23
  • SSH port number is 22

These are all the standard ports.

TCP is suited for applications that require high reliability and transmission time is relatively less critical. TCP guarantees the recipient will receive the packets in order by numbering them, it is used on the Internet and it is a three way handshake protocol for connection and acknowledgement is compulsory after a packet is received.