Routers

A Router is a device that transfers data from one network to another in an intelligent way. It has the task of forwarding data packets to their destination by the most efficient route.

In order to do this, the router has a micro computer inside it. This holds a table in memory that contains a list of all the networks it is connected to, along with the latest information on how busy each path in the network is, at that moment. This is called the 'routing table'.

When a data packet arrives, the router does the following:-

	Reads the data packet's destination address
	Looks up all the paths it has available to get to that address.
	Checks on how busy each path is at the moment
	Sends the packet along the least congested (fastest) path.

Other tasks the Router can perform:

	Exchange Protocol information across networks (see page on protocols).
	Filter traffic - useful for preventing hacker attacks for example

Routers operate at the network level of the OSI model.