Introduction to Router

Router is a network communication device that is used to connect logically and physically different networks. It can be used in the Ethernet, FDDI, Token Ring, ATM, Frame Relay, ISDN and other types of the LAN/WAN.  The router’s main purpose is the sorting and distribution the data packets.  Router contains and maintains the routing table that has the information of the adjacent routers and other connected networking devices.

Router selects the shortest possible path to send the data packets at the destination. It is an intelligent device that can connect ATM with Frame Relay, ISDN with Frame Relay, SONET with ATM or any other two dissimilar networks. Router uses different protocols such as RIP (Routing Information Protocol), OSPF (Open Shortest Path First) and BGP and IGRP (Interior Gateway Routing Protocol) and EIGRP (Enhanced Interior Gateway Routing Protocol. Routing protocols specifies that how routers will communicate with each other in the WAN. 

They determine that which path to select to send the data towards its destination. There are three main types of the routing protocols i.e. link state, path vector and distance vector.  Router contains the operating system, Flash memory, NVRAM and processor.  High level routers contain the Application Specific Integrated Circuits to perform parallel processing.  A router is also act as a gateway that connects LAN with the internet.

 For communications between the routers, ports, protocols and the IP addresses are used. Today many types of the routers contain the built-in firewall to fulfill the security needs of the home or office networks.  There are different manufactures of the router such as Cisco, Nortel, D-Link, Lucent, Juniper, Motorola and Novell. Cisco Systems is the biggest manufacturer of the routers.  There are many different types of the routers manufactured by Cisco.

 These types include Cisco 12000 Series Routers, Cisco 7600 Series Routers, Cisco 3600 Series Multiservice Platforms, Cisco 1700 Series Modular Access Routers, Cisco 3800 Series Integrated Services Routers, Cisco 7300 Series Routers and Cisco 7200 Series Routers etc. Cisco has the maximum shares of the routers manufacturing in the world. Some types of the routes are used in the ISP, some in the Enterprise networks and others are used in the home or office network.   

For home and business users that use the high speed DSL connection a router also act as a hardware firewall device.  It filters and blocks the unwanted traffic based on the IP address, port, protocol, application and service.   Before buying router for deploying in your home or office network make sure it is compatible with other devices in your networks. It is recommend that you buy and deploy the all the network devices from the same vendor.