What Are Ports and Their Functions?
When devices communicate over the Internet, the TCP and UDP protocols handle the connection, break down the data into packages, send them, and then reassemble the packages at the receiving end. To make this process work smoothly, the operating system on each device uses ports as gateways for the data transfer.
A port is like a virtual door on a computer, allowing data to flow to and from specific applications. Each port is assigned a unique number, which helps the system know where to direct the data once it arrives. For example, one port might be for web traffic, another for emails, and so on. The port number is included in each data packet, helping the receiving device figure out which application should handle the incoming data.
Types of Ports
Ports are numbered from 0 to 65535, and these numbers are divided into different categories:
- Well-known Ports (0–1023): These ports are reserved for widely used services and applications. For example, port 80 is used for HTTP (web traffic), and port 25 is used for SMTP (email).
- Registered Ports (1024–49151): These ports are assigned to specific applications or services by the Internet Assigned Numbers Authority (IANA). Developers can register these ports for their software.
- Dynamic/Private Ports (49152–65535): These ports are not permanently assigned and are used for temporary or private connections. For example, web browsers use these for creating temporary connections while browsing.
What is a Port Number?
A port number is a unique identifier assigned to a specific application or service on a device. While an IP address ensures data is sent to the correct device, the port number ensures the data is sent to the correct service or application within that device. For example:
- Port 80 is reserved for HTTP traffic (web browsing).
- Port 25 is used for SMTP (email sending).
How Do Ports Make Network Connections More Efficient?
Ports allow a computer to manage multiple types of data traffic simultaneously, even though they all travel through the same network connection.
For instance, let’s say Bob sends an MP3 file to Alice using FTP (File Transfer Protocol). This file will be sent to port 21, which is dedicated to FTP. Alice’s computer will recognize the data as an FTP transfer and process it accordingly, storing the file.
At the same time, Alice’s computer might be receiving webpage data over port 80 (used for HTTP). Even though both the MP3 file and webpage data are coming through the same internet connection, the port numbers help Alice’s computer know exactly what to do with each type of data — one for the file transfer application, the other for the web browser.
Summary
- Ports are virtual points that manage data transfer between devices and specific applications.
- Port numbers help direct data to the correct application or service on a device.
- Ports help make network communication more efficient by allowing multiple types of data (like web browsing and file transfers) to flow through the same network connection without interfering with each other.
| Services | Unsecured | Secured |
| FTP ( File Transfer Protocol ) | 21 | 22 |
| SSH | 22 | |
| SMTP ( Simple Mail Transfer Protocol ) | 25 | 587 |
| Apache (Http ,Https) | 80 | 443 |
| IMAP (Internet Message Access Protocol) | 143 | 993 |
| POP 3 ( Post Office Protocols ) | 110 | 995 |
| DNS (Domain Name System) | 53 | 853 |
| MYSQL ( My Structure Query Langauge ) | 3306 | – |
| NFS ( Network File System ) | 2049 | |
| C – Panel ( Controll Panel ) | 2082 | 2083 |
| WHM ( Web Host Manager ) | 2086 | 2087 |
| Web Mail | 2095 | 2096 |
| Solus Vm | ||
| Virtulizor | 4085 | 4086 |
| RDP (Remote Desktop Protocol) | 3389 | |
| PLESK | 8880 | 8443 |