What is Router in Computer Networks?

Router is a smart networking device that works in the network layer. It connects multiple packet switched networks and subnetworks. Router manages traffic between these networks and also allow multiple devices to use a single internet connection.

In this article, we will learn what is router, its working, types, advantages and disadvantages. Let us get started.

Table of Contents

• What is Router in computer networks?
• How does it work?
• Types
• Uses
• Advantages
• Disadvantages

What is Router?

A router is a networking device that can be either physical or virtual. It receives, analyzes, and routers data packets among computer networks and devices. It works in the network layer, the 3rd layer of the OSI model. It is a layer-3 device since the decision for primary forwarding is based on the information in layer-3 IP packet, especially the destination IP address. In the OSI model, data packet switching is done through a router based on the address on layer 3. 

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How does router work?

A router is connected to multiple data lines from different IP networks. When a data packet reaches one of the lines, it reads the information about the network address in the packet header to determine the destination address. It uses the information in its routing table and directs that packet to next network on its journey. 

Router comes with firmware that is automatically installed within that helps it perform various functions. It connects devices within a network by forwarding the data packets among them. The data can be sent among devices or from device to the internet. For this, the router assigns a local IP address to every device on the network. It ensures that data packets are reaching the accurate destination without getting lost.  

Uses of Routers

Following are the major uses of a router:

1. Multiple network connection: It connects multiple networks and forwards data packets that are destined for direct or remotely attached networks.
2. Managing congestion: It manages traffic between networks by forwarding data packets to the destination address. It also allows multiple addresses to use the same internet connection. 
3. Providing connectivity: Large routers interconnect several Internet Service Providers (ISPs). Small routers provide connectivity for homes and office networks.
4. Connecting subnets: Routers are used for connecting multiple logical groups of computer devices called subnets with the different network prefixes. 
5. Port forwarding: They are also used for port forwarding among private ISPs.
6. Traffic classification: A router with the help of QoS, takes the decision on which data packet should be first processed. 

Types of Routers

The following are different types of routers that are used by individuals as well as enterprises: 

1. Edge router

Also known as a gateway router, it is a specialised router that acts as an intermediary between different networks. It resides at the edge of a network. Edge ensures connectivity of its network with wide area network (WAN), internet or external networks. For connectivity with remote networks, Edge uses the network protocol External Border Gateway. Edge routers have ethernet ports as inputs to connect with the internet and have multiple outputs for connecting additional routers. 

2. Wireless router

It is a device that acts as a router as well as a wireless access point. Such routers provide access to private computer networks or the internet. Based on the model, it can function in either a wired local area network, wireless-only LAN or a mix of the wired and wireless network. In functionality, they are a combination of edge and distribution routers. These routers have one or two USB ports that can be connected to a device and used as a shared resource on the network. 

3. Virtual router

It is a software-based framework with the same function as physical routers. These routers run on commodity servers and are packaged either alone or with other network functions. However, they increase the reliability of a network through virtual redundancy protocol.

4. Distribution router

It is a router in the local area network of a single organization. Also known as an interior router, it receives data from Edge router via a wired connection and it sends this to the end user. This is usually done through Wi-Fi. 

5. Core router

It is a computer communication device that operates at the core of the internet. It links all network devices to provide multiple fast data communication interfaces. Usually, service or cloud providers use core routers. This router provides maximum bandwidth to connect additional routers. It supports multiple telecommunication interfaces of the highest speed and should be able to forward IP packets at full speed. 

Advantages of Using Routers

Following are the advantages of using routers: 

1. Determines the most efficient path between source and destination using dynamic routing algorithms such as OSPF, BGP, RIP, etc. 
2. Reduces network traffic by creating the collision domains and broadcast domains. 
3. Provides connection among different network architecture. 
4. Connects multiple users to a single network connection. 
5. Uses alternative parts to avoid problems in routing networks if an external network component fails. 

Disadvantages of Using Routers

Following are the disadvantages of using routers:

1. Hardware-based routers are vulnerable to cyber attackers since they contain software called firmware. Unpatched routers are quite vulnerable to cyber attacks.
2. Since routers analyze data transmission from physical to network layer, they are slower than repeaters and bridges. 
3. There is less bandwidth for user data since dynamic router communications cause additional network overhead. 
4. Routers also face compatibility issues with 5GHz frequency. 

Conclusion 

Hope that this article has been helpful in understanding routers in detail. These are smart networking devices that can offer a single network, but have limitations related to low speed and bandwidth. While choosing a networking device, you should consider a device that suits your requirement with minimum limitations.