What Is A Router?

Date First Published: 2nd March 2022

Topic: Computer Networking

Subtopic: Network Hardware

Computer Terms & Definitions

Difficulty: Easy

Difficulty Level: 3/10

CONTENTS

Types Of Routers
Home Networks
WANs
History

Learn more about what a router is in this article.

A router is a device that can form a LAN by connecting devices within a building. It shares an internet connection between multiple devices and sends data packets from one device to another. The data packets consist of several layers and carry important information, such as the sender, data type, size, and destination IP address. This layer is read by the router and the best route is chosen for each transmission.

A router has a lot more features than other network devices, such as a hub or a switch, which can only perform basic network functions. For example, a hub can transfer data between computers or network devices but does not analyse or process the data. On the other hand, routers have the capability to analyse data delivered through a network, change the way that it is packed, and send it to another network or across a different network.

Note:

They are called routers because they are devices that 'route' data from a LAN to another network connection. Without routers, it would be impossible to connect multiple devices to the internet as the internet connection could not be routed to multiple devices. If only one device needs internet access, it could directly connect to a modem.

Types Of Routers

Five different types of routers exist, which include:

Core router - A very powerful type of router that is used in large computer networks. It is the backbone of a network, since it links all network devices together. They are mostly used by service and cloud providers, such as Vodafone, Amazon, and Microsoft. Most small businesses don't need to have core routers. However, very large businesses with employees working in various different locations and buildings may use core routers as part of the architecture of their network. Core routers route data within a network, but not between networks.
Wireless router - These routers provide a wireless internet connection and are mostly used by homes and small offices. They serve as an access point in a LAN and provide the basic infrastructure for a home or small office network. Wireless routers combine the features of edge routers and distribution routers.
Virtual router - Also known as a vRouter, a virtual router allows a computer to become a router itself using software that mimics the functionality of hardware-based Layer 3 IP functionality. Virtual routers enable computers to have the capabilities of a fully developed router by carrying out the network and packet routing functionality using software.
Edge router - A specialised router that is located at the edge or boundary of a network and allows new traffic. Edge routers do not usually provide Wi-Fi or the full ability to manage networks. Normally, edge routers only have Ethernet ports, which allow other devices to connect to them. In addition, these contain outputs, which can connect additional routers. External Border Gateway Protocol is used by edge routers, which is used on the Internet to provide connectivity with remote networks. Edge routers are found at the edge of the network of an ISP.
Distribution router - This type of router receives data from the edge router through the use of a wired connection. It then sends it to users through network technologies, such as Wi-Fi and Ethernet and includes functionality to connect additional routers.

Home Networks

In a home, a router is used for enabling internet access. A router physically connects to a modem by a network cable. The modem is the device that connects the home to the ISP and takes the signals that come from the ISP in order to translate them into digital signals for the router to be used. In homes, routers are used for sharing a single internet connection between multiple computers. Modern routers usually have four Ethernet ports.

WANs

WANs are large networks that are spread over wide geographical areas. Large organisations and companies that operate in multiple locations will need separate LANs for each location, which connects to the other LANs in order to form a WAN. Multiple routers and switches are necessary for operating a WAN because it is designed to cover a large area. It is important to note the difference between network switches and routers. Network switches work by forwarding data packets between groups of devices in the same network and routers forward data between various different networks.

History

The first Xerox routers were working after early 1974. Ginny Strazisar at BBN Technologies created the first IP router as part of the DARPA-initiated project in 1975–1976. Three PDP-11-based routers were in use in the experimental prototype Internet by the end of 1976.

In 1981, staff researchers at MIT and Stanford originally developed the first multiprotocol routers, both of which were based on PDP-11s. William Yeager created the Stanford router programme and Noel Chiappa created the MIT router program. TCP/IP is now used in almost all networking, but multiprotocol routers are still available. When protocols other than TCP/IP were being used in the early stages of computer networking, they were very important. Modern routers that support both IPv4 and IPv6 are multiprotocol, but they are less complex than those that support AppleTalk, DECnet, IP, and Xerox protocols.

General-purpose minicomputers were used as routers from the mid-1970s to the 1980s. Modern high-speed routers are network processors or highly specialised computers that include additional hardware acceleration to speed up both standard routing functions, such as packet forwarding and specialised capabilities like IPsec encryption. For research and other purposes, Linux and Unix software-based computers running routing code are commonly used. The Cisco IOS operating system was developed independently. Junos and NX-OS are two major router operating systems that are significantly altered versions of Unix software.