There are many standardized ports in computer systems, which are dedicated to various tasks. TCP/IP ports are used in data transfer from one computer to another, mainly for Internet services. This article provides an explanation regarding different types of these ports.
Data transfer between computers requires certain set of rules. TCP/IP protocol suite is a collection of commands that are used for the Internet services. TCP and IP were the two protocols that were standardized at first, and after this, the standardization of the other protocols was started. Internet is a huge connection of computers and network devices, and all of them have an IP address. This address has a number of TCP ports that initiate and receive connections. The receiver ports are more important than the initiating ones.
Explanation
The following table will briefly tell you everything about these ports:
| Ports | Service Name | Description |
| 0 | Reserved | Reserved |
| 1 | TCP MUX | TCP Port Service Multiplexer |
| 7 | Echo | Echo |
| 21 | FTP | File Transfer Protocol is used to send large files. |
| 22 | SSH | Secure Shell |
| 23 | Telnet | Telnet is a network protocol and uses the command line interface on the remote computer. It is an interactive session based on protocol and uses a connection based protocol. |
| 25 | SMTP | Simple Mail Transfer Protocol uses commands for interaction and can send large files from one device to another. |
| 38 | RAP | Route Access Protocol |
| 41 | Graphics | Graphics |
| 44 | MPM-flags | MPM FLAGS Protocol |
| 45 | MPM | Message Processing Module |
| 49 | TACACS | Local Host Protocol (TACACS) |
| 50 | Re-Mail-Ck | Remote Mail Checking Protocol |
| 52 | XNS | Xerox Network Systems |
| 53 | Domain | Domain Name Server uses UPD for interaction and TCP for relatively large files. |
| 57 | MTP | Mail Transfer Protocol |
| 67 (only UDP) | BOOTPS | Bootstrap Protocol Server |
| 68 (only UDP) | BOOTPC | Bootstrap Protocol Client |
| 69 | TFTP | Trivial File Transfer Protocol |
| 80 | HTTP | World Wide Web HTTP (Hypertext transfer Protocol) is a TCP based messaging protocol. |
| 93 (only TCP) | DCP | Device Control Protocol |
| 109 (only TCP) | POP2 | Post Office Protocol 2 |
| 110 (only TCP) | POP3 | Post Office Protocol 3 |
| 143 | IMAP | Internet Message Access Protocol |
| 153 | SGMP | Simple Gateway Monitoring Protocol |
| 161 (only TCP) | SNMP | Simple Network Management Protocol |
| 179 (only TCP) | BGP | Border Gateway Protocol |
| 389 | LDAP | Lightweight Directory Access Protocol |
| 427 | SLP | Service Location Protocol |
| 444 | SNPP | Simple Network Paging Protocol |
| 631 | IPP | Internet Printing Protocol |
The transport layer of the Internet protocol suite uses the TCP and UDP. In addition, some of the other protocols use numerical identifiers for the host-to-host communication. These identifiers are known as port numbers, and these endpoints are known as ports. The port numbers are assigned by IANA (Internet Assigned Numbers Authority), and on most of the systems, they are used as processes (programs) only. These ports are named by logical connections, and are connected to carry long-term conversations. A port number is always assigned to the receiver endpoint so that the transmitter endpoint must know the port number (in turn, the receiver endpoint), to which the connection should be made to start the conversation. Initially, when this concept came into existence, there were only 0-255 ports. Later, 0-1023 ports were introduced, and the range was expanded.