What is Router?
· The router is a physical and virtual internetworking device that helps us to receive ,forward and understand data packets between computer networks.A router first examines the a destination IP address of a given packet data and uses the headers and forwarding tables to decide the best way to transfer the packets .
· Router is used in LAN and WAN networks.For example,we can use it to connect two distinct places like USA and India. It shares information with other routers.
· It uses the routing protocol to transfer the data across networks.A router usually has two ports ,one for the connection to local network and another for connection to external network.A router is three layered device that connects the networks.
Take an example ,If an USA user wants to access LAN server of WCE Sangli then he/she have to do following things:
1)Routers works on the third layer of OSI model and it is based on IP addresses of a computer. It uses protocols to communicate between two or more network.
2)In OSI model first data packets of required information are formed in application layer and send to network layer. In this network layer server gives the information of destination server (USA) which wants to access the data. In this layer server will give IP address of USA and MAC address of WCE server. The packet is send to the switch. It switches the packet to the next device which is router. Once the router has received the signals, the packet will continue through cables, from this router and out to the world wide web.
3) Internet is made of many routers connected together. The packets may take different paths to arrive at the destination. Then router will analyze the destination IP address of given packet header and compares it with routing table to decide the next path of packets.Routing tables have a set of rules that compute the best path to forward the data to destination (USA) . Once the packet is arrived to the destination router it is passed to the appropriate switch and ultimately the packet will be passed to the device.
4)Router has to send data to the USA user which requested it. Router will direct packets from modem to the computer that have to receive.
In this way USA user will access data from the WCE Sangli.
Features of Router :
· Router works on the network layer of OSI model and it is able to communicate with its adjacent devices with the help of IP addresses and subnet.
· Router provides high speed internet connectivity.
· It allows the user to configure the ports as per the requirements in the networks.
· Router creates various paths to forward data.
· Routers have a routing table in it, that is refresh periodically according to the changes in the network. In order to transmit data packets, it consults the table uses a routing protocol.
· Routers are more expensive than other networking devices like hubs, switches and bridges .
Functions of Router:
· Forwarding-
Router receives the packets from its input ports, checks it header, perform some basic functions like checking checksum and then looks up to the routing table to find the appropriate output port to dump the packets onto and forwards the packets onto that output port.
· Routing-
Routing is the process by which the router finds what is the best path for packet to reach the destination, it maintains a routing table which is made using different algorithms by the router only.
Routers are classified as one of the following-
1) Static routers:
These must have their routing tables configured manually with all network addresses and paths in the internetwork.
2) Dynamic routers:
These automatically create their routing tables by listening to network traffic.
Applications of routers:
1)Routers are used to connect hardware equipment with remote location network and other servers.
2)It provides support for fast rate of data transmission, hence it is used in both wireless and wired communication.
3)Internet service providers widely use routers to send and access data in the form of email, a webpage, image, voice messages etc. Furthermore, it can send data all over the world with the help if IP address of destination.
4)Router offers access restrictions. It can be configured in a way that allows for few users to access the overall data and allows the other to access few data only which is defined for them.
There are many benefits of router such as security, performance enhancement, reliability, etc.