Understanding how networks work on a basic level

The Basics of Networks

Understanding how networks work on a basic level is fairly simple but can quickly become complicated. This is especially true if you are unfamiliar how the technology within different networks functions. From a mechanical point of view, computer networks across the world all function very similarly. While there will be differences between hard wired and WiFi networks, the basic ideas behind these two systems is very similar. In order to fully understand all of the different complications and complexities that come with computer networks one must start at the beginning.

Any of the number of different networks and network types out there function on one simple principle: the connect two or more computers together and allow them to communicate. The most common type of physical connection between computers is through Ethernet. Ethernet uses category five, or Cat 5, cable and an RJ 45 jack to connect up. The cable inside this is usually crossed over, meaning that physical connections on either end are different yet interchangeable. This allows for a better signal and longer length of cable. The cable will then go into an Ethernet port on the computer or server. Once this physical connection has been established the two computers can now talk back and forth. You can also use a device called a router that allows multiple computers to connect up to each other. The router usually will have multiple connection ports coming into it. Any computer that has a physical link with the router can now talk to any other computer that has a physical link to it as well. Understanding these basic concepts will allow you to visualize any of the millions of networks around the world.

Now that you have the computers connected up they need a language to talk to each other. This language is called in computer terms a protocol. Over the years many different protocols have been developed, but the most common networking protocol used today is TCP/IP. Others from the past include SPX, IPX, as well as a host of other proprietary ones. While you will find them in use on occasion, TCP/IP is by far and away the most common of all the networks around the world. TCP/IP is actually a combination of two different protocols that work in tandem. TCP, or Transfer Control Protocol, describes how files will be transited between two computers.

Using this protocol one computer can take files and break them down into tiny packets that can be received and built back into the file by the computer on the other end. IP, or Internet Protocol, describes the location of the computer so that the data knows where to go. Each computer that is any of the TCP/IP networks needs to have an IP address. This address will let other computers on the network know where the computer is. Each computer however does not have a unique IP address. This is where things start to get a bit more complicated and understanding how networks work together gets a bit more interesting.

The IP address of every computer will contain four different numbers ranging from zero to two hundred and fifty five. A typical IP address may look something like this: 192.168.1.100. No two computers on the same network can have the same IP address, although two computers on two separate, non public networks can have the same IP address. This does not mean that two computers with the same IP cannot communicate, in fact more than likely the computer your are working on right now shares an internal IP that is the same as many other computers out there in the real world. In order to understand why this is the case you need to be able to visualize how these computers interact. The world wide web is one singular network. Every computer on this network has its own unique IP address. There are certain addresses that cannot be on the world wide web. This becomes important as those addresses and range of addresses become the basis for all internal networks.

So now you are probably asking yourself, if every computer on the world wide web has its own address, and my computer does not have its own unique address, how is it that I am able to connect with other computers? A very good question. This is all handled through the magic of networks, or more specifically is handled by routers. Earlier I mentioned that routers can connect up multiple computers. This is true. In addition to this they can also assign an IP address to those computers. What this means is that the routers can then create an internal network. Typically they will create these networks from the range of IP addresses that are not used on the world wide web.

What then happens is the router will be given an IP address on the world wide web and then handle all communications with the outside world for its internal network. This has a couple of effects. Number one it increases the total number of computers that can be on the world wide web, and number two it protects all the computers behind the router from being attacked. Because the router handles all the communications for the computers behind it, external computers will only see the router and not the computer that the information is coming from. This makes you system much safer as no one can launch a direct attack against you without first attacking the router.

This is only the basics of networks. Things get even more complicated when you start having networks inside of networks inside of networks. This should give you a basic idea of how networks work so you have something to build off of.