First, what is the gateway
Gateway is a computer system or a device for converting the task of acting as. Between the use of different communication protocols, data formats, or language, or even completely different architecture systems, a gateway translator.
Second, the gateway, which has several types
(1) Internet Gateway:
In the Internet, the past is now called the gateway router. Gateway now refers to a system which converts the network and application protocols, make the TCP / IP network, and TCP / IP, the Internet users and applications can communicate with each other. Gateway also refers to the translation device between applications. Proxy server gateway is a firewall that allows users to access the Internet, intranet, while prohibiting Internet users from accessing the internal network. Full-featured firewall offers advanced screening, verification and proxy to prevent and *** *** to enter the interior systems.
(2) LAN gateway:
LAN gateway provides data transfer between the LAN channel. Usually due to intervening LAN using different protocols, data conversion needs to be done to pass. Many routers provide Ethernet and FDDI connection, you can either act as this. Further, there is provided a gateway AppleTalk and TCP / IP, with the IPX, TCP / IP protocol conversion.
(3) IBM host gateway:
The LAN workstations are connected with an IBM mainframe system. The first terminal gateway 320 emulates an IBM mainframe, workstation LAN so that the terminal becomes master. A bit more complex gateway allows to transfer files between the PC and the host, or client / server mode of operation, allow the PC to access the database host. IBM's APPN network layer protocol provides the same service, so that the host become part of the network. The current trend is the host also supports TCP / IP, connection through the Web server and the user directly with TCP / IP or together, no longer need a dedicated gateway.
(4) e-mail gateway:
Responsible for message conversion information between different vendors use software that allows users to share online letter different e-mail applications issued. Common e-mail gateway converts the format-specific information into X.400 format.