- An example of a router is a mail carrier.
- An example of a router is a woodworking tool.
- An example of a router is computer hardware that transfers Internet messages to a laptop in another room; a wireless router.
- a plane for gouging out recesses and smoothing the bottoms of groovesin full router plane
- a machine for routing out areas on a wood or metal surface
- One that routes, especially one who prepares shipments for distribution and delivery.
- Computers a. A device in a network that handles message transfers between computers.b. See gateway.
router - Computer Definition
An intelligent switch capable of deciding where to forward packets based on a view of the network as a whole. A router is a programmable device that works with other routers, via a routing protocol, to establish the best path on which to forward a packet with a given address. A router can consider the network as a whole in determining the route for a given call. A router can be programmed to consider a number of factors including the addresses of the originating and destination devices, the least-cost route, the least congested route, the route with the fewest number of hops, and the geographically shortest route. Routers operate at least at Layer 3, the Network Layer, of the OSI Reference Model. Simple switches operate at Layer 2, the Data Link Layer, seeing only an individual link, and having no sense of the larger network. Depending on the applications, routers can operate at higher layers, as well, including Layer 7, the Application Layer. Routers can be capable of performing the gateway functions associated with protocol conversions such as code conversions or those necessary to connect dissimilar networks, such as circuitswitched and packet-switched networks. See also Data Link Layer, gateway, hop, Network Layer, OSI Reference Model, packet, protocol, and switch.
A network device that forwards data packets from one network to another. Based on the address of the destination network in the incoming packet and an internal routing table, the router determines which port (line) to send out the packet (ports typically connect to Ethernet cables). Routers require packets formatted in a routable protocol, the global standard being TCP/IP, or simply "IP." In the Home In the home or small office, a "wireless router" is commonly used to manage Internet traffic. It is a combination device that houses a router, network switch and Wi-Fi in one box (for details, see wireless router). In a Company Enterprise routers are dedicated to packet forwarding only and can cost from 10 to more than a hundred times as much as a wireless router. They take factors such as traffic load, external line costs and congestion into consideration to determine which port to forward to. Measured in millions of packets per second (see PPS), large routers can handle enormous amounts of traffic. Routers in the Core Within the enterprise, routers separate local area networks (LANs) into subnetworks (subnets) to balance traffic within workgroups and to filter traffic for security purposes and policy management. They also forward packets between the company's LANs and wide area networks (WANs). See LAN and WAN. Within the Internet, very large-scale routers do all the packet switching between the national and regional backbones and are typically connected via optical fibers. See Ethernet, SONET, edge router and collapsed backbone. Routers, Switches and Access Points In a local network (LAN), routers connect to Ethernet switches. The router forwards packets between networks, and the switch forwards packets between machines within a network. Wi-Fi is provided by separate base stations that plug into the switches (see access point). Routers work at the network layer (layer 3) of the protocol, whereas switches work at the data link layer (layer 2), also known as the "MAC layer." See TCP/IP and data link protocol. Specialized Machines or Regular PCs Routers are specialized computer-based devices optimized for communications; however, router software can be added to a server. For example, NAT32 (www.nat32.com) is Windows software that lets a PC function as a router to the Internet. The major router vendors for enterprises and service providers are Cisco, Alcatel-Lucent, Huawei, Juniper and ZTE. Router Terminology Routers used to be called "gateways," which is why the term "default gateway" means the router in your network (see default gateway). For more details on the routable protocol layer (network layer 3), see OSI model and TCP/IP abc's. See layer 3 switch, route server, router cluster and routing protocol.