Computer ports

     Computer ports are connection points or interfaces with other peripheral devices. There are two main types of computer ports: physical and virtual.

Physical ports are used for connecting a computer trough a cable and a socket to a peripheral device. Physical computer ports list includes serial ports ( DB9 socket ), USB ports ( USB 2.0 or 3.0 socket / connector ), parallel ports ( DB25 socket / connector ), ethernet / internet ports ( RJ45 socket / connector )….

Computer Ports

Virtual ports are data gates that allow software application (network) to use hardware resources without any interfering. This computer ports ( network ports ) are defined by IANA ( Internet Assigned Numbers Authority ) and are used by TCP ( Transmission Control Protocol ), UDP ( User Datagram Protocol ), DCCP ( Datagram Congestion Control Protocol ) and SCTP ( Stream Control Transmission Protocol ).

Virtual computer port

 

     In computer networking a port is associated with an IP address and a protocol used for communication. Each address and protocol is identified by a 16 bit number, known as computer port numbers. 

     In this day’s most desktop and notebook computers use only USB, VGA, Ethernet, IEEE 1394, DVI and TRS physical ports. Serial, parallel, PS/2 and SCSI are used more by industrial and professional computers.

Phisical common computer ports – short description

-          USB port (Universal Serial Bus) created in mid-1990’s mainly to standardize communications between computers and peripheral. Also USB ports can be used as a power supply for different devices like digital cameras, microcontroller programmers, laptop coolers and other. There were four types of USB computer ports: USB1.0 and 1.1 released between 1996 and 1998 with a speed range starting from 1.5 Mb up to 12 Mb ; USB 2.0 released in 2000 with a maximum speed of 480 Mb/sec and USB 3.0 released in 2008 with a maximum speed of 5 Gb/sec ;

-          Ethernet / internet ports was first introduced in 1980 to standardize the local area networks ( LAN  ). Internet ports use RJ45 connectors and have speeds between 10 Mb/sec, 100 Mb/sec and 1 Gb/sec, 40 Gb/sec and 100 Gb/sec ;

-          VGA ports ( Video Graphics Array ) has 15 pins displayed on three rows and it is mainly used for connecting the monitor with the video adapter from the computer motherboard; adapters :

·         HDMI ( High-Definition Multimedia Interface );

·         SCART;

·         DVI ( Digital Visual Interface );

-          IEEE 1394 ports, this technology is developed by Apple between 1980 and 1990 with the name FireWire and it is the equivalent of the USB for Apple computers;

-          TRS ports are used for receiving and transmitting with analog signals like audio;

-          DVI are computer ports used to transmit uncompressed digital video data ;

-          PS/2 ports were introduced in 1987 to replace the serial mouse and keyboard;

-          Serial port uses the DB9 socket / connector and transfers information, one bit at a time, between the computer and other peripherals. The serial computer port identifies with RS-232 standard.

Virtual common computer ports and numbers – short description

-          FTP port ( File transfer Protocol ) – for network data transfer uses the 20 and 21 TCP ports by default;

-          PPTP port (Point-To-Point Tunneling Protocol) – for implementing virtual private networks uses the TCP / UDP port 1723 ;

-          SFTP port ( Secret / Secure File Transfer ) – protects the data flow and uses the 22 TCP port ;

-          NTP port ( Network Time Protocol ) – for clock synchronization uses the 123 UDP port;

-          HTTP port (Hypertext Transfer Protocol) – main protocol for data comunication in the World Wide Web, uses the 80 TCP port;

-          SMTP port ( Simple Mail Transfer Protocol ) – for e-mail routing, uses 25 TCP port;

-          SQL port ( Structured Query Language ) – for data management in relational databases, uses TCP / UDP port 118, 156.

In essence computer ports connect peripherals (through a cable) or applications (through a network) to a computer.

For more information about computer ports please browse the web site or follow the links on the text above.