Computer Ports - Brief description about computer ports

Computer Ports

The term ports refer to the physical or virtual connection point between different devices. In computer port is generally know as female portion of the connection. Port is used for different functions such as connecting Monitors, LCD's, LED's, Printers, Scanners, Webcam and may other peripheral devices with the computer.

Ports are divided on two layers

1. Physical Layer Port
2. Transport Layer Port

Physical Layer Port

Port which is physically exists or a specialized outlet on specific equipment from which plug or connector connects. In electronic term ports is a portion where several conductors provide method to transmit signals between different devices when port and connector connects with each other.

Transport Layer Port

A application specific or process specific software used to transmit data from one device to other connected device with the help of operating system is know as port. The main purpose of port is to identify the different applications and processes running on a single computer are identified uniquely while they are using one physical connection in packet switched network like internet. Each port is associated with the IP Address of the device and the type of protocol used to perform communication.

Ports are divided into two major parts

1. Physical Port
2. Virtual Port

Physical Port

Port which is used to connect computer with peripheral device using cable and socket is know as physical port. Physical port on computer are Serial Port (DB-9), USB Port (USB 2.0/ 3.0), Parallel Port (DB-25) and Ethernet or Internet Port (RJ-45).

Electronically physical ports are divided into two groups based on signal transmission

• Serial ports send and receive only one bit at a time using one pair of wire.
• Parallel ports send and receive multiple bits at a time using multiple pair of wires.

There are different types of physical port

1. Digital Visual Interface
2. Display Port
3. E-SATA
4. IEEE 1394 Interface (Firewire)
5. PS/2 Connectors
6. Serial Port
7. USB
8. VGA Connector
9. Parallel Port
10. Ethernet or Internet Port
11. SCSI
12. HDMI
13. Audio
14. Microphone

Virtual Port

Virtual port are gates that allow network to transfer data over the network with the help of resources available without any interference. These computer port are defined by IANA (Internet Assigned Numbers Authority) and are used by different protocols such as TCP (Transmission Control Protocol), UDP (User Datagram Protocol) and many more. Virtual ports are part of TCP/IP Networking Model.

Here is the list of few ports and the purpose for which each port is used

1. 20 and 21 used for FTP (File Transfer Protocol)
2. 22 used for SSH (Secure Shell Host)
3. 23 used for Telnet remote login service
4. 25 used for SMTP (Simple Mail Transfer Protocol)
5. 53 used for DNS (Domain Name Server) Service
6. 80 used for HTTP (Hyper Text Transfer Protocol) used in WWW (World Wide Web)
7. 110 used for POP3 (Post Office Protocol)
8. 119 used for NNTP (Network News Transfer Protocol)
9. 143 used for IMAP (Internet Message Access Protocol)
10. 161 used for SNMP (Simple Network Management Protocol)
11. 194 used for IRC (Internet Relay Chat)
12. 443 used for HTTPS (Hyper Text Transfer Protocol Secure) or HTTP Secure
13. 465 used for SMTPS (Simple Mail Transfer Protocol Secure) or SMTP Secure