In the beginning, the earliest functional iteration of a large scale network was funded by Defense Advanced Research Projects Agency (DARPA) and it created a link between UCLA and Stanford Research Institute in October 1969. By December of the same year, two more universities were added to the network: the University of Utah, and the University of California. At that time, it was known as the ARPANET.

With these networks growing so quickly, a problem eventually became apparent. There was no central global address book.

Computers communicate much the same way as the global Postal systems work. On an envelope, a sender will include both their originating address and the destination address. A computer will do likewise, but first it must know the destination address. And this isn’t just for email — it’s for everything. Every act you perform on the internet is just a series of messages back and forth. And at that time, unlike our friendly-named streets and cities, computers relied on mathematical formulas and strange binary information to form their addresses (they still do, but now also have DNS). So these universities had to manually keep a special text file on each of their computers that listed the IP address and name of every other computer on the network. If someone wanted to add a new system to the network each computer would need to add it manually. So you can see how this would quickly be found burdensome. Imagine if every time a new website opened, we needed to look up the information and then put it in a massive text file. Manually. Billions of times.

At it’s core, what DNS does is match up the un-friendly binary IP address information with more friendly names. So instead of browsing Google by going to http://173.194.123.34 (which works, incidentally, at the time this post was written), you can simply type in “google.com” and then DNS checks who google.com is, and it goes from there. This is why you hear websites and IT people talking about a “Domain Name” — the friendly-name portion of the Domain Name System or, DNS. By the 80’s DNS was pretty mainstream.

Another use for DNS is that it tells incoming communications which server to use to deliver things like Email, which is called a Mail eXchange (MX) record, because most large enterprises have a vast number of servers, each with a specific purpose, so it is not practical to have one address that does everything.

So who controls who gets what Domain Name? That would be the Internet Corporation for Assigned Names and Numbers (ICANN) who, in turn, delegate authority to other organizations to maintain it. You don’t ever really own a Domain Name, you merely lease it for a period of time. You can keep it for as long as you continue to renew it, or decide to sell it.

The virtue of DNS is the fact that the friendly alias is easy to remember. The simpler the name, the easier it is for people to remember, and theoretically the more visitors one can expect. Because Domain Names are so relatively inexpensive, this has led to Domain Name hoarding, which is why so many new web platforms have odd misspelled names. All the normal dictionary words are already taken, often by people looking to make money on selling them to the highest bidder. The names themselves have a perceived value — the most expensive domain name to date was Insurance.com, purchased for $35.6 Million in 2010.

Someone asked me recently how best to set up a wireless router so that streaming and general internet use are both quick.

Wireless is nearly its own field of expertise, and it gets complicated very fast. But I’ll do my best to keep things simple while still touching on the important stuff. For the sake of simplicity I’ll focus on home wireless solutions but the principles also apply to commercial applications.

Metrics

The first thing I must explain is how networking speed is measured, which isn’t really what I would call accessible or intuitive to average consumers. So without further ado, I introduce you to the bit.

You’ve probably heard that computers all communicate with 1s and 0s. Well the bit is who you’re hearing about. It is an individual unit of data which is expressed by electrical impulses (1) or lack thereof (0).

Then you’ve almost certainly heard of its family, the byte. A byte consists of eight bits. Humans typically use what is referred to in mathematics as a “base 10” numbering system (10, 20, 30, etc.), especially in metric. Computers favour binary (1, 2, 4, 8…) and hexadecimal (1-9, a-f) so for the sake of simplicity, just trust me that there is a good reason that a byte has eight bits and that it makes sense to the computer.

Next in the units of measurements would be kilobyte which is 1024 bytes, followed by megabyte which is 1024 kilobytes and then the gigabyte which is — you guessed it — 1024 megabytes. Why 1024? Binary math again. Just ignore it. The list goes on but I’ll stop there.

Network speeds are measured in megabits per second (Mbps). The standard network speed for years has been 100 Mbps, but is leaning now towards gigabit-speed networks. This is sometimes confusing because the abbreviated form of megabits is Mb while megabytes is MB.

So the important thing to note here is that to translate speed ratings into more relatable terms, one must convert megabits into megabytes. Or in other words, “how long will it take for me to download this movie?”. So to do that, we divide the number by 8. To save you the effort, a 1 Gbps network is theoretically capable of 120 Megabytes per second; a 100 Mbps connection capable of 12.5 Megabytes per second and so on.

Wireless speeds are rated differently. The units of measurement are the same, but they have different speed standards that have improved between wireless technology generations.

Wireless networks are governed by a communications standard with a not-so-catchy name: IEEE 802.11. 802.11 is the specification for general wireless, but there are several revisions of that spec.

Keep in mind that this is an extremely simplified version of the wireless specifications. But as you can see, the general speed increments are a bit odd. 54 Mbps, 135, 780, and even these speeds are a bit of a misleading maximum. I’ll get to that in a bit. For now just keep in mind that the current standard is 802.11n and that would theoretically allow you to download 20 minutes of music in about one second if all the stars are in alignment.

Wait, Why Does My Wireless Router Say It’s 300 Mbps?

Good catch. In fact some wireless routers claim 450 Mbps. These use something called MIMO, which involves multiple antennas taking advantage of wireless physics to stream more data simultaneously. The speed of each antenna is still restricted by the wireless spec, but the overall effect is more speed and better range. However it is still plagued by some of the issues which I’ll now get into.

Complications

The biggest problem with wireless presents as a result of physics. If you think of wireless like sound, you’ll get the idea pretty quickly. It doesn’t move very well through solid objects. This is why cell phone calls get dropped on elevators and driving in mountain ranges. The more solid the object, the worse the signal gets. Sure, you could yell through a wall and someone can listen and possibly understand on the other side, but no one will ever record an album that way.

Wireless is so sensitive to solid objects that even furniture has a measurable impact on performance.

Worse still, speed isn’t the only factor. Range is also a concern. Each wall, each floor, each piece of furniture between you and the wireless device will reduce both the speed and functional range of the device. So when you look at a wireless device and it says it has a range of say 200 feet, you can take that to mean that if you live in the prairies and place the device in the centre of a corn field, you may get adequate wireless for up to 200 feet in any direction (further complicated by the position of the antennae if they exist).

Yet another problem with wireless is that not all specifications are what we call “asynchronous” or “full duplex”. These are fancy ways of saying that information can flow simultaneously in both directions. Humans typically take turns speaking and listening, but computers can handle hundreds, even thousands of “conversations” simultaneously. Wireless, unfortunately, is only half-duplex. So although the information travels very fast, the reality is that the speed is effectively cut in half to allow each computer to take it’s turn.

But wait, there’s more! The “half-duplex” problem is bad enough when you’re dealing with one wireless laptop and one wireless Access Point (AP). Now put a handful of wireless devices and each one has to wait its turn to talk. This further reduces the perceived performance of the network for each user.

Even more issues. Wireless is very susceptible to interference. In an apartment building, your wireless router has to compete with sometimes dozens of other devices competing — yelling over each other’s voices. That’s not even mentioning other devices like cordless phones, cell phones and even — and I’ve seen this firsthand — microwave ovens. Worse — it even interferes with itself! A natural radio-wave phenomenon called multi path causes transmitted information to bounce off walls, ceilings, and other objects, reaching the receiving antenna multiple times via different angles and at slightly different times. This forces the receiving device to wait until it has all of the transmission before re-sequencing the message in the proper order.

Seriously, there’s more. There are some types of traffic that are particularly “noisy” and can dramatically reduce the performance of the network for everyone, and even crash the network in the event too much data is being handled for the AP to deal with (especially true of consumer-grade, off-the-shelf network equipment). This applies especially to things like torrents and video streaming.

Enough Science, How Do I Make My Wireless Go Fast?

Now that we know the most common issues with wireless internet, getting the best performance out of it is really about reducing or eliminating the problems. Fortunately there’s a solution to nearly every one.

To maximize range, an AP should be placed in a central location with as few obstructions as possible. If there are dead spots, either a more powerful device is necessary, or more likely, multiple APs.

By configuring the wireless to operate in the 5GHz frequency you can reduce or eliminate the interference from neighbours and other wireless devices, but with a small penalty to range. But interference has an impact on both speed and range anyway so it’s generally an improvement anyway.

If you have many wireless devices in a network, the most ideal solution is to reduce that number. If a system can be wired, wire it. In some cases it’s most appropriate to have multiple APs and to distribute the load between them. With two APs, wait time is theoretically cut in half. However, having multiple APs does introduce a measure of interference but again, it’s a trade-off.

Anything Else?

Yes! Most quality routers come with something called QoS or Quality of Service. This allows you to set a priority for certain traffic types. So let’s say you have a VoIP (Voice Over IP aka an internet phone) system that you run wirelessly, and a family member who likes to stream videos and download torrents. This has a drastic impact on the quality of your phone calls: causing voice delays and dropped calls. Setting QoS can put that call traffic at a higher priority than all others, so that even if someone else is hogging all the bandwidth, the system will automatically throttle their traffic to give you what you need.

Wireless traffic is usually encrypted — hence the need for a password for private networks. Even the method of encryption can have a dramatic effect on the quality, speed, and range of the internet connection. But wireless security is way beyond the scope of this blog post which has already bloated beyond what I had intended.

Is There An Alternative To Wireless?

I’m glad I asked. Yes! In an ideal world, all modern homes should be wired for networks at the same time and with the same attention as electrical. Sadly this is not the case even in newer homes, and adding that kind of wiring after the fact is usually way outside the budget.

IEEE 1901 to the rescue! Without further bloating this blog post, I wrote about these PowerLine Ethernet devices years ago. Basically it hijacks your existing electrical system and takes advantage of electrical “noise” to communicate between devices. The theoretical speeds of these devices range from 200 Mbps to 500 Mbps but these have their own list of issues that reduce that performance in the real-world.

Conclusion

Wireless is complicated. Very complicated.

Some sites you can stick a AP to a wall and that’s all there is to it. Others need more fine-tuning, which is why I often lend my services to home automation companies to handle their more difficult wireless projects.

By following the principles I’ve listed, you’ll eliminate the “low-hanging fruit” of wireless issues.

Did I miss anything? Was this too complicated? Let me know in the comments.

An integral part of a secure network is the Firewall. But why? What is it? Does everyone need one?

Most people know that a Firewall is what hackers “hack through” in films and television, but beyond that it’s a mysterious black box that works its magic invisibly.

The Bouncer

The most common form of firewall is what you might compare to a bouncer at an elite club or restaurant. There is a list of acceptable customers (network traffic) that the bouncer will accept through the door. All others he turns away. This list can be very specific about which individuals it allows in (as identified by an IP address), or it can be more general and simply state the types of people allowed in (as identified by protocols such as those used by the web, email, etc). This type of firewall is readily available in virtually all consumer network equipment and operating systems.

The “Bouncer” firewall prevents unauthorized access to the network. Or more importantly, the information it contains.

The Warden

The other aspect of a firewall keeps information from getting out. The “Warden” aspect has a similar list to the Bouncer, but he’s facing inward. This type of firewall is usually only found in commercial-grade network devices and software.

Forgetting the Warden metaphor for a moment, this can be used to compartmentalize networks and network traffic, and even prevent the spread of viruses. More commonly it is used to restrict the types of traffic permitted on a given network, for example streaming video, audio, or torrents which can quickly accumulate to become resource hogs in networks of all sizes. Technically speaking, this is the more traditional definition of “firewall” since the original term came from the practice of placing a partition made of fireproof material to prevent the spread of fire from one part of a structure to another, such as on a plane or ship (especially around the engine compartment).

Do I Need a Firewall?

This is a simple question with a not-so-simple answer: sometimes. Most devices have at least a rudimentary firewall built into them. The capabilities and behaviour of those firewalls will vary from platform to platform: Windows, Mac, Android, Linux, and a long list of variations therein have a type of firewall.

Whether or not you need one depends on the environment. If you have a router at home, this device acts as a firewall between you and the outside world. In this case it is not imperative to use a firewall on your computer. However it doesn’t hurt anything by running one.

If you happen to have multiple computers at home, again you likely have a router which offers some protection from the outside world via a firewall. But in this case if you want to share information between computers, a firewall may prevent this communication, so you may consider disabling it when at home. However this second computer may belong to someone who you don’t want snooping around your computer, in which case you may want to leave the firewall enabled.

The same principle applies to a public space: a coffee shop, an airport, or a public hotspot are places that you have no control over. Even though most public wireless are configured in a way that isolate devices from each other, it’s still safer to have a firewall enabled.

In a business environment, there will almost certainly be a firewall in place (or at least there should be) between the office and the internet (same as at home: the router). Whether another firewall is configured and maintained on individual servers or computers is largely up to the requirements of the host business.

Did you like this explanation of a firewall? Is there another technology you’d like explained? Please leave a comment below.