Definitions[edit | edit source]
A router is
|“||[a]n intermediate device on a communications network that expedites message delivery. On a single network linking many computers through a mesh of possible connections, a router receives transmitted messages and forwards them to the correct destinations over the most efficient available route. On an interconnected set of local area networks using the same communication protocols, a router serves the somewhat different function of acting as a link between networks, enabling messages to be sent from one to another.||”|
|“||[a] computer system in a network that stores and forwards data packets between local area networks and wide area networks.||”|
|“||[a] computer that is a gateway between two networks at OSI layer 3 and that relays and directs data packets through that inter-network. The most common form of router operates on IP packets.||”|
Overview[edit | edit source]
Using a routing table, it finds the best path for forwarding ("routing") a packet to the next router on the network until all of the packets are received at the destination computer, where all of the packets in a message are reassembled.
|“||Most routers owned by ISPs are collocated at facilities housing IXPs or ISP backbone switches. End users typically keep their routers at their own sites. . . . [R]outers fall into two classifications. Some routers are used to move information within a particular ISP. Routers used for this purpose are called interior routers. Routers that move information between different ISPs are called exterior routers.||”|