McLean IT Consulting

WORRY FREE IT SUPPORT

Call Us: 250-412-5050
  • About
  • Services
    • IT Infrastructure Design
    • Remote & Onsite IT Support
    • Disaster Recovery
    • IT System Monitoring
    • IT Audit
    • Documentation
    • Medical IT Solutions
    • Wireless Networks
    • Cloud Computing
    • Virtualization
  • Partners
    • Lenovo
    • Ubiquiti Networks
    • Dragon Medical Practice Edition (Nuance)
    • Synology
    • Drobo
    • Adobe
    • Bitdefender
    • NAKIVO
  • Contact
  • Blog
  • Remote Support

The Great Big Wireless Post

December 3, 2014 By Andrew McLean Leave a Comment

IEEE 802.11Someone 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.

Screen Shot 2014-11-21 at 12.21.20 AM

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.

Filed Under: Technology

What is a Firewall?

November 23, 2014 By Andrew McLean Leave a Comment

gandalf shall not passAn 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.

Filed Under: Technology

Why You Should Stop Buying Overpriced HDMI Cables

February 10, 2013 By Andrew McLean Leave a Comment

In the days before I was an IT consultant, I used to work in retail. Wal-Mart, to be specific. Say what you will about Wal-Mart, but they had a great customer service training program. I worked in the electronics department as I’m sure comes as no surprise. This was before High-Definition and overpriced HDMI cables. In fact, DVD was just starting to gain popularity.

Something that I learned while I worked there, was that just because somebody works in a specific department, does not mean that they have any idea what they are talking about.

Every day, I would observe a customer come into our department asking for this cable or that adapter. But most of the people that I worked with didn’t know any more about electronics then the customers did. They didn’t know to tell you that the AG13 button cell battery is the same as in LR44 or an A76. Or that a Hi-8 tape won’t fit in a DV camcorder. So I usually had to be the one to rescue my associate by jumping in to help.

Every once in a while, I couldn’t get there fast enough, and I would find them explaining to the customer some technology that they knew nothing about. And what they were telling them was completely wrong.

I don’t know what compels people to pretend to know what they’re talking about, rather than admit that they don’t, and offer to help them find a solution anyway.

The point I’m taking a long time to reach is that even in retail atmosphere where there is no incentive for an employee to mislead a customer, some will do it anyway. Maybe they’re just repeating what they heard, maybe they’re trying to save face, or maybe they’re trying to make a sale. In any case, it happens. A lot.

I will admit that whenever I am contemplating a big purchase such as a TV or a computer, I will sometimes head on over to a big box retail electronics store and pretend to be completely oblivious to technology, allowing the salesperson to explain it to me. I’m not sure why I do it. Maybe I’m a masochist. Or maybe I get a twisted pleasure out of knowing that I know more than they do.

Besides the compulsory extended warranty, the one constant is that they want you to buy gold plated, gas injected Monster cables. Particularly when dealing with high-definition displays, the salesperson will explain that higher quality HDMI cables will result in a better quality picture and sound. I usually let them run through their spiel until they’re finished and kindly decline.

Expensive HDMI cable
3.3 Foot, $500 overpriced HDMI cable

At this point, it’s important to note the difference between analog and digital storage and transmission.

Take for example your voice. You can broadcast your voice through a telephone call, and the receiving end would hear it, but at a lower quality than the original. This is an example of analog. Your voice is still being translated into an electronic format, but the medium by nature is analog. The signal degrades. Same with a record player. You could technically record from one vinyl record to another, or cassette tape to cassette tape, but each subsequent copy will be worse than the one before.

On the other hand, if you record your voice on your computer, and send that audio file to a friend, their copy of the file would be exactly the same as yours. Why? Because when transmitting digital data, it either transfers, or it does not. When you connect to the Internet, this is a digital connection. You do not require gold-plated cables to connect to the Internet. Likewise for HDMI cables, the high definition signal either goes to the display, or it does not. There is no higher or lower quality by virtue of the fact that this is a digital signal.

I’m not sure whether these salespeople are being intentionally misleading, or if they’re just so indoctrinated that they just believe. After all, it is logical to expect that these monster cables must be so exorbitantly expensive for good reason. Unfortunately, this is not the case.

I found this infographic that sums it up. Hint: you’ll have to zoom in to read it because it’s huge.

HDMI cable infographic

Filed Under: Technology

Fax Modem Sounds Explained

February 8, 2013 By Andrew McLean Leave a Comment

Maybe it comes with the territory, but I always found fax modem sounds oddly comforting. I personally never had internet by dial-up – we first started accessing the internet at home by broadband using Windows 98. Before that, I think our elementary school used dial-up but it was invisible to the end-user.

Ever wonder what exactly it is that modems are doing when they make their signature screech? Blogger Oona Räisänen explains with an article and poster-sized accompanying graphic.
fax modem sounds diagram describing the anatomy of the bi-directional communication

For those of you really excited by this graphic, I would encourage you to buy the large print poster. $4 from each item goes to Oona.

Filed Under: Technology

Windows 8 Picture Password

January 23, 2013 By Andrew McLean Leave a Comment

Windows 8 has nifty new gesture-based “picture password”. Just be careful, as your fingers leave an oily residue trail on the screen and constitutes a security risk.

http://www.youtube.com/watch?v=XBmtde_XNBs

Filed Under: Technology

  • « Previous Page
  • 1
  • 2
  • 3
  • 4
  • Next Page »

Contact Us

McLean IT Consulting Inc.
Serving Greater Victoria

P: 250-412-5050
E: info@mcleanit.ca
C: 250-514-2639

Featured Article

PSA: SWEET32 vulnerability in OpenVPN

According to a security release by OpenVPN back in August, OpenVPN is vulnerable to attack on 64-bit block ciphers, such as 3DES and Blowfish — the … Continue Reading

Blog Categories

Our Mission

We seek to enrich and improve small and medium businesses by delivering best-in-class technology solutions, and offering a premier customer service experience. Contact Us Now!

Quick Menu

  • About
  • Testimonials
  • Contact
  • Blog
  • Sitemap

Let’s Get Social

  • Email
  • Facebook
  • LinkedIn
  • Twitter
  • YouTube

Copyright © 2025