The Common Network (A Postman’s Guide To Networking Part 1)
Hey there! If you’re reading this, you’re here because you are hoping to get a better understanding of the networking model. Whether it be for a profession or general interest, networking is an important concept to understand for anyone who wants to excel in the IT world because of its ubiquity.
Because networking is such a huge concept, this is the first part of a three-part blog. I’ll start off by covering the fundamentals of networking beginning with local area networks.
By the end of part 2, we’ll have covered the fundamentals but there’s still so much more to learn! I’d recommend this Network Overview to not only get a different perspective, but also for further reading.
In part 1 of the guide, I’ll cover the general components of the networking properties:
- Network Overview
- Local Area Networks (LAN)
- MAC Addresses
- Ethernet
Let’s dive in!
Network Overview
Let’s delve into what a network is. Fundamentally, a network is a link of two or more computers. There are many types of networks but in this guide we will be discussing two types: Local Area Networks (LAN) and Wide Area Networks (WAN).
LAN
A LAN is the common network. It covers a small area, usually a room, house, campus building, etc.
Imagine a row of houses.
Now imagine that there is a cable that connects each house with the houses next to it.
Now one of the qualities of a LAN is that either all of the devices are connected by multiple cables that establish a single connection (as in our example), or they are connected via a wireless device like a hub or a switch (shown below).
Now using that neighborhood model, let’s say you want to communicate with your neighbor and ask them whether or not they would like to come by tonight for dinner. That would be pretty simple. You just walk over and give the door a knock. But instead of right next door, let’s say you are in a neighborhood still connected by a single road, but now each house is about a mile apart. Walking over isn’t as convenient, so how do you communicate!?
MAC Addresses
If you’re going to communicate, you’re going to need a starting point (the place where the communication will be sent from) and an ending point (the place where the communication will be sent to). The way to denote those starting and ending communication points is through addresses - similar to how it’s done in the real world when you send something via mail. There’s a return address (your address) and the destination address (the person’s address). Just like your address is permanent and fixed to your residence, addresses of the computer - known as Media Access Control (MAC) addresses - are unique and permanent to the device as well.
And in the same manner that your address is decided by powers beyond your control (most likely by the city/town in which your humble abode resides), the MAC address is set up by the manufacturer of the device and is usually found on the label of the device.
MAC addresses are depicted as a combination of letters and numbers.
Ethernet
In a computer network, the ‘road’ that links devices is a cable called Ethernet. There are two types of Ethernet cables: 1) twisted pair cables and 2) Fiber Optics. Twisted pair cables have been around longer and are the most common today. They have evolved in recent years in terms of performance, however each one is depicted the same, as seen below.
Twisted cables have a maximum length of 100 m (328 ft) and data transmission rates between each can range from 10 Mbit/S (Megabits/Second) to 10,000 Mbit/S.
To put that into perspective, if you have a file that’s about 12.5 megabytes, and you are using a 100 Mbit/S capable Ethernet cable, you will *theoretically be able to transfer that over to your destination in one second!
* Many things are taken into account to determine speed, including network traffic, such as the amount of devices connected in a network that are communicating via the network at a given time.
There are three types of Ethernet networks:
- Fast Ethernet: Capable of transferring data at rates of 100 Mbit/s. It is likely that the computer laptop device you have will be equipped with a 100BASE-TX/10BASE-T Ethernet interface (a.k.a. 10/100 interface), which supports 10 Mbit/s and Fast Ethernet connections. The twisted pair cable you will use for this type of connection is called a Cat-5 cable.
- Gigabit Ethernet: Will soon replace Fast Ethernet as the network standard as it supports up to 1000 Mbit/s (1 Gbit/s) data speeds. The twisted pair cabling used for Gigabit Ethernet connections are known as Cat-5e cables, but higher versions such as Cat-6a and Cat-7 can also be used.
Fiber cables such as 1000BASE-SX (up to 550 m/1,639 ft.) and 1000BASE-LX (up to 550 m with multimode optical fibers and 5,000 m with single-mode fibers) are used for transmissions that exceed the limits of twisted pair cabling.
3. 10 Gigabit Ethernet: Network capable of allowing for data caps that can reach 10 Gbit/s (10,000 Mbit/s). Twisted pair cables capable of working on this network are Cat-6a and Cat-7. Fiber optic cables are able to reach distances of about 10,000 m (6.2 miles).
The simplest example of a network is when two computers are connected via a network/Ethernet cable (such as the blue twisted pair cable from the pics above).
So Ethernet cables establish a connection between devices, but how exactly does a message travel through that wire?
Stay tuned for Part 2 where I’ll cover the answer to that and more!!
If you’d like to read up more about the topics I’ve covered here, then please check out the links below!
1. LAN
