A router is a packet data network device designed to combine network segments and its elements and serves to transfer packets between them based on any rules. Routers work at the network (third) level of the OSI model as node devices for various technologies: IP, ATM, Frame Relay, and many others. other
One of the most important tasks of routers is to choose the optimal packet transmission route between connected networks. Moreover, this must be done as quickly as possible with a minimum time delay. At the same time, the current situation in the network should be monitored to exclude overloaded and damaged sections from possible delivery routes. Almost all routers use the so-called routing tables. This is a kind of database that contains information about all possible routes for packet transmission with some additional information that is taken into account when choosing the best delivery option. This may be the channel status, information delivery time, congestion, bandwidth, etc.
An example of the operation of routers in a packet data network
An important aspect of the operation of routers is the method of updating information in routing tables. This can be done in two ways manually and automatically. In the first case, the network administrator independently configures the routing tables. This option is only suitable for small networks whose configuration is rarely changed. Routers of the first type are called static. Automatic updating of routing tables is performed by exchanging information messages between neighboring routers about the current situation, as well as checking the connecting channels between them. Such routers are called dynamic. Their main drawback is the need for additional network and computing resources for data exchange and route calculation. However dynamic …