A Complete Guide to Network Devices
Ever wondered how internet works or what devices are used to get the internet and what are the network devices such as modem , router , hub , switch etc. In this blog , we going to understand these terms.
Internet
Internet is global network of networks which is interconnected using some standard protocols (rules). It is the system where networks are connected globally. In laymen language it is the road where data travels and enables us to access websites, emails, communicate, transfer data and services, etc. More than 95% of Internet travels through fibre wires. So there are literally fibre optic wires spread undersea through which countries and continents are connected and it transmits data across wires at near light speed. And yes it is maintained periodically, it’s a common case where some kind of fish damaged the wires, later it was fixed, still the internet doesn’t break or stopped why because there are several routes to reach one destination. At the coastal area there are cable landing stations to get the data from the wires and provide it to us, to our homes or office, which is done by ISPs (Internet Service Provider), that is a topics for another day. Now Internet is owned by no one, but everyone, means it is decentralized.
WWW
Majority of people things WWW is internet. The full form is World Wide Web and it runs on the internet. So www is the collection of websites and webpages which are served as per the response. When we request a website like Facebook or google etc., WWW provides us and are some protocols which we will discuss next time. Internet existed before WWW, before that people are able to sharing information using text-based systems like emails, news etc. WWW was built on top of internet it transformed internet to more visualized and interactive network.
Let’s take an example, earlier we used to have Telephones which we can use it for only voice calls nothing more or less , but nowadays we have smartphones which can do more things like video calling, messaging , touch interaction and better UI , so although the smartphones are using same underlying network or technology but they are much more visually appealing or friendly. Smartphones didn’t replaced it , it is made on top of it , That is the same thing with WWW and internet, in this example internet is telephones and www is smartphones .
Router
Router is a networking device, which allows multiple devices (PCs, laptops, mobiles etc ) to connect for sharing data packets between them based on the IP addresses. Router determines and selects the best path to transfer the data. Router connects LAN to WAN by doing this we are now connected to web. Generally we can say, routers are placed between Modem and our local network. Router uses NAT(network address translation ), to connect multiple devices and use a single public IP’s, which make them scalable and helps to make us unreachable from outside networks unless it is required like a basic firewall. Some routers provides you the First level of security means blocking malicious domains, malware protection, WIFI capabilities , etc.
Modem
Modem stands with Modulator Demodulator. Just like computers don’t understand our human languages, internet also needs some other form of data to understand. Modem perform two a way process, modulation and demodulation, to share data. So modulation is converting of digital signals into signals suitable for the transfer and then sharing it with ISP and the exact opposite vice versa is called demodulation. Modem acts as a bridge between your home network and ISP for converting signals, making a path etc.
Hub
Hub is a old and basic networking device used to connect multiple devices into it to transfer data. Hub shares the data with every devices connected with it regardless of sharing it with the actual devices which had made the request, it’s like a I want to hear a song, but the song can be heard by everyone in the room. It doesn’t have any privacy. Hub doesn’t have any intelligence and it doesn’t store any type of address that’s way it doesn’t process data it just throws it. You can rarely see a Hub, nobody uses it because of the privacy and security concern everybody have shifted to Switch.
Switch
It is a modern networking device which does the same thing as Hub does but efficiently and effectively. It respects privacy since save the MAC addresses of devices to share the data only to the device requested it and it is fast comparatively to hub.
Now believe you got the answer , for why to choose switch over hub.
Firewall
There are different types of firewall but the overall use cases are pretty much same. Think of firewall as a wall, which only let’s the authorized and trusted data. It is acts a security between the internet and your network which monitors and controls the incoming and outgoing for traffic filtering, harmful & untrusted, unauthorize data. Protects us from suspicious ports ,unwanted traffic etc.
Load Balancer
Websites can grow up to a mark where it handle millions of users. How will it handle this much request in only one server, either it will crash, go down etc. So Load Balancers, is a physical device or a software, as the word suggests it helps to distributes the incoming requests or traffic to multiple server intelligently .Think of a busy restaurant where there is a long queue and only one employee behind the counter, that one employee will be frustrated, overwhelm, tired, here comes the manager opens up tens more counter and divides the customers into this counter intelligently and yes the manager is the load balancer. This will help the website or systems to be ;-
Scalable - As the users grow, we can use more servers, distribute traffic and grow easily.
High availability - Since traffic is distributed, there must be a server which will be available to users, so much less waiting time.
Security - Protects from DoDs or excessive untrusted attacks.
Flexibility and maintainability - Easy to maintain since there’s much less pressure to single server
Resource utilization -> Resources are equally utilized by all the servers and balanced .
End-to-end network architecture for a web application
So generally web request or any kind of request for communication or sharing resources from your device or network (e.g. PC or phone etc.) goes to switch device which already stores the MAC addresses of the devices connected to it, it transfers the data to router, router have the private IP addresses of the devices and it uses a single public IP using NAT which provides some kind of protection to our network, router is connected with modem , data flows through modem for conversion, it’s form from digital to suitable form which internet prefers with modulation, ISP routes the data based on it’s port, address etc. and send it to the desired server, now if the load is too much load balancer plays their role of distributing traffic intelligently along servers and servers replies the response through the same route backwards. Since the process is so lengthy, although it doesn’t take that much time, everything is done in few milliseconds but yes sometimes it takes time .
