What is a Gateway

Functions of a Gateway

Devices used to connect networks running different protocols are called Gateway. Gateway is a generic term used to represent devices that connect two dissimilar networks. Gateways can be hardware devices software running on a computer or a combination. Depending on the manner in which a gateway connects the networks, the following types of gateways are defined:

• Network gateways
• Protocol gateways 
• Tunneling gateways

Network Gateways: Connect different networks that use the same network layer protocol. Network gateways are usually routers, which contain routes to reach nodes outside the network to which the router is connected.


Protocol Gateways: Protocol gateways are usually computers running protocol conversion software. Protocol gateways connect networks that use different network layer protocols. As per example, a protocol gateway can transmit data between a network that uses IPX/SPX and another network that uses TCP/IP. Protocol gateways convert the addressing format of the data packet from the source network to match the addressing format used in the destination network. In the preceding example, if the data originates from the IPX/SPX network, the addressing format of the data packet is converted to TCP/IP addressing, and the data is transmitted to the TCP/IP network. 

The protocol conversion feature is inbuilt in the  some Microsoft Windows Operating System, as per example Windows NT 4.0, 2000, 2003, 7, 8.1, 10 etc..Computer running these operating system can be configured as protocol gateways.

Tunneling Gateways: Encapsulate the data packet of the source network in a protocol that is recognized by the destination network. As per example, if the source network uses IPX/SPX, and the destination network uses TCP/IP, the gateway encapsulates or wraps the IPX/SPX data with TCP/IP header and trailers so that the destination network can recognize the data packet. The router on the destination network unwraps the data packet to retrieve the original data, which is then transmitted to the destination node. Gateways used in Virtual Private Networks (VPN) are examples of tunneling gateways. 

Gateways are capable of transmitting data across networks that use different network layers protocols.

Function of tunneling gateway is to transferring information between two networks.

Identify the Function of Switches in a Network

 

Thanks a lot for reading!
 Neel Kamal