Internet is like a complex spider web
Hello learners and welcome to this interesting topic on Internet infrastructure. This is a simplified article on the network infrastructure for those who are new to the world of networks and computers.
As you know, internet consist of two words: inter + net meaning that it interconnects thousands or millions of small webs that are interconnected together using cables, switches and routers. Let’s consider the image below and talk about it.
As you can see in the above picture, there are many small webs (each small cells) that are interconnected together using cables. The small joints can be a switch or a router depending on the network topology but mostly a router.
Why we call it World Wide Web (WWW)? because it is very big in terms of scope and is globally interconnected devices and cables. You probably saw this at the beginning of websites like www.google.com.
The spider itself can perform the function of an ISP (Internet service provider like Rogers, Bell, AT&T) that interconnect all of these small networks together (in real world, there are many ISPs that connect networks together). ISP is very important since all of these small networks must be managed and we need a centralized place to join all of these small networks so they can talk together and exchange data between each other. That is why we need ISPs to join all of these small networks together. The fact is that the underlying infrastructure is more complex than the scope of this article but we will make it as simple as possible.
But how do we address and find one specific network on this big web? here the IP address comes into play and it is much like the address on the envelope. The postman reads on the envelope and sends the letter to that destination. Each network has its unique IP address like homes and buildings.
Now, we have all of the cables and router and switches set up, then we need a rule that governs and controls data exchange between all of these devices. In computer world, we call it “Protocol”. A protocol is a rule or guideline that govern the way devices on the network talk together. The protocol will define some specific rules for each device making it very specific when talking to this device. Routers, switches, cables, all have pre-defined specific rules (protocols) that enables them to talk on the network and exchange data.
Protocols in computer world are a lot which is not in the scope of this article but if you are interested to see each protocol function, then you can be found here, https://en.wikipedia.org/wiki/Lists_of_network_protocols. Each protocol performs certain function to deliver data across the network.
When data is traveling across the networks and mediums, protocols govern data exchange from one device to another to talk to that specific device. Let’s say that we have many languages around the world. If we consider each language as a protocol, then we can say that when we want to talk to certain people in a specific geographical location, we need to know the language of those people to talk to them.
Let’s say that in one specific region in Toronto (ISP A1a and A1b) has 10,000 small networks interconnected. Another location is Vancouver (ISP C1b and C1a) has 50,000 small networks interconnected. Let’s say that you want to send an email from your computer located in Toronto to your co-worker in Vancouver. Now, how we can exchange data from ISP A1a (your ISP) to ISP C1b (your co-worker ISP)?
Remember that the address is IP address here. Networks on the internet has unique IP addresses and you can find every network via its IP address (like home address).
Here ISPs with the help of IP address shine and exchange their information together and advertise (based on specific protocols) their networks together. So, ISP A and ISP C will interconnect together using ISP B. ISP A will advertise its networks to ISP B and C. Also, ISP B and ISP C will do the same. So, all the ISPs have all the address of all the networks and now they can send data between each other.
For example, ISP A says, hey ISP B, what networks are connect to you? ISP B will respond with its direct networks (B1) and indirect networks (ISP C networks)). Also ISP C must know the ISP B and ISP A networks.
Note: we have different layers of ISPs but here we do not cover it because it is very specific and technical.
The scope of some subjects like protocols, switches, routers, cables, ISPs, and more is very big and detailed and we cannot explain all here. If you are curious about all of these devices and underlying hardware, you can do a quick research on google and find some good articles about each device and medium.
