What is a Gateway?

The gateway is a part of the communications architecture that is located at the point where two networks connect but do not operate under the same transmission method or format.

In telecommunications, the gateway acts as a point for both entry and exit to/from a network. All information in a network must go through or communicate with a gateway before it can be routed from one node to another in that network.

For example, most IP networks only have traffic that does not go through at least one gateway between nodes that physically reside in the same segment of the local LAN (local area network). Default gateways, or network gateways, are also used to refer to gateways.

How Gateways Work

Every communication network has a communication boundary for limiting communications to those devices physically connected to the network.

Therefore, in order for any network to communicate with other devices (nodes) or networks outside of its boundary, the network must use a device (gateway) that has routing capability. A gateway is generally defined as a combination of both a router and a modem.

The gateway is placed at the boundaries of an internetwork and is responsible for controlling all of the data going in or out of that network. When one internetwork wants to talk to another, it passes a packet of information to the gateway and then sends it to its final destination via the most efficient route possible.

In addition to routing information, gateways can also act as repositories for information about the internal routing pathways of their respective networks and the routing pathways of other networks they have encountered.