Networking chops. Do you need them or can you rely on vendors?

*This post was originally posted at AVNation.tv, but I felt that it belonged here, as well.

As a residential integrator, you’ve spent countless hours learning the ins and outs of, say, Dolby Atmos, HDBaseT, how to dim LED fixtures, the nitty gritty of your chosen control platform and more. Commercial systems integrators invest in similar countless hours educating themselves on sound reinforcement, staging, video walls, video conferencing products, the nitty gritty of your chosen control platform and more. Countless. Hours. The respective lists are long, sometimes overlap, and always require significant commitments to training. One system that both residential and commercial A/V and control systems professionals rely on and should be actively focused on is the network.

Sadly, and despite many years of industry banter about “convergence”, I believe we have a long way to go.

I recently attended an informal meeting with a prominent lighting control vendor, manufacturer’s reps and dealers. We were discussing wireless communications and the vendor’s upcoming plans to use 6LoWPAN, a wireless protocol that resides in the 2.4GHz frequency spectrum for device to device transmission. Their intention to use yet one more non-Wi-Fi protocol in the 2.4GHz range concerned me and I said so. I brought up the fact that 6LoWPAN packets can’t be demodulated by Wi-Fi devices on the same 2.4GHz band and, therefore, they would be adding to the overall noise floor, increasing interference. This is because 802.11 Wi-Fi uses a “listen before you speak” mechanism known as Carrier Sense Multiple Access, Collision Avoidance (CSMA/CA) that relies on the ability to demodulate 802.11 frames present and waiting until the RF medium is clear before transmitting. This vendor’s plan to utilize 6LoWPAN, an 802.15.4 protocol, has the potential to decrease performance of both the vendor’s equipment and the Wi-Fi networks already installed in the same and neighboring structures. This is due to the high probability of simultaneous, interfering transmissions.

The 2.4GHz band is often described as the “junk band” because it is shared by so many competing, non-cooperative technologies. Along with the aforementioned Wi-Fi and 6LoWPAN, additional examples include wireless handsets, analog video transmission, Bluetooth, Zigbee, and Z-Wave. All of these technologies coexist on the shared medium, namely air, but not without the potential to interfere with one another. Why are there so many protocols and communication technologies using that band? In the US, it’s part of the free, unlicensed ISM (Industrial, Scientific and Medical) band under the jurisdiction of the FCC. The ISM band is free to use but, not without regulations or some caveats. One such critical directive is the concept that devices must accept interference from other sources.

So, where am I going with this?

In discussing the issue, I argued that a case could be made for using Wi-Fi instead of other competing protocols on the same frequency. Yes, Wi-Fi chips require more power. So what? We were talking about lighting control products that would, by necessity, be powered over wire. Yes, 802.11 is meant for transporting large amounts of data while 802.15.4 protocols are designed for sending the small amount of data needed for the vendor’s product. OK, says I. We’ll have overhead to grow into if desired. The real issue, as I see it, is that by using 802.11 frames, we can utilize the benefits of CSMA/CD to allow their product to coexist with the WLANs we’re responsible for. Sure, we would have to share precious airtime but, at least we’d be sharing. We wouldn’t be stepping on one another’s toes. We then went on to discuss how the network could be optimized to most efficiently pass typical Wi-Fi data frames while segregating the vendor’s control and feedback frames. Specifically, we talked about the need to divide the WLAN into separate segments/broadcast domains by configuring VLANs…and that’s when things got really interesting.

In response to my case for a more “advanced” WLAN design, 25 year industry veteran and respected rep, Dave Thomas of the Momentum Group argued that vendors shouldn’t rely on the LAN/WLAN until networking vendors make it “easy” for integrators. He suggested that too many dealers aren’t prepared to manage networks at such a high level unless it’s done for us by network vendors that cater to us. On these points, I had to agree and disagree. I agree that far too many integrators have not invested in the training, capable gear, testing, and time necessary to properly deploy well designed networks. I see it far too often. Instead, I see dealers relying on vendors and third parties to do the “hard work” for us and this is where I disagree with Dave. I don’t subscribe to the idea that third parties should be holding our hands through something as fundamental as networking. I believe that the responsibility is ours as dealers, technicians, and trusted value added resellers. The onus is on us to invest in our knowledge base and experience.

The AV and controls industry has reached a point where we are now the target audience of otherwise unknown network vendors. These are firms that have virtually zero exposure in the larger IT industry and have no apparent traction outside of the AV and controls space. One such company describes their products as “designed exclusively for custom installers”. What does that even mean? Is it an indication that we, as an industry, aren’t educating ourselves on networking standards, topologies, designs, configuration, maintenance and install techniques? Are we so far behind that they are a legitimate crutch upon which we should be leaning? Are these companies taking advantage of our weakness?

I don’t think so. I think these companies are doing what companies do. Selling a product to willing customers. Do they really add value? Personally, I don’t see it and don’t recommend their gear. Instead, I believe that what they really offer is an opportunity. An opportunity for us to hold up a mirror and think long and hard about our capabilities. If we are willing to work hard, train, and practice, we’re able to create incredible electronic environments out of ridiculously complicated equipment. Why aren’t we able to do the same for the networks upon which our systems communicate?

The fact is, we don’t need others to prop us up. We have the responsibility to better ourselves. Our clients have high expectations and unless we are well grounded in the fundamentals of our craft, which includes our LANs/WLANs, we are doing them a disservice. Educational opportunities abound. Test labs are an inexpensive way to improve our skills. We have strong social media channels with which we can bounce ideas off of one another. When we take these steps and learn how to support ever more capable networks, we open the doors for vendors to confidently bring to market products that we can reliably place on them.

Apple Airports Abhorrence Admission

This post started as a long email that I edited just a bit to make more sense here and I thought it made for a reasonable blog entry. Enjoy…

[intro to email removed to protect the innocent]

These devices are so dumbed down, appealing to the general consumer who has no idea how to setup any aspect of a home network, as to be virtually unusable in any advanced configuration. They are clearly aimed at the single device, router/AP/switch combo environment and only for those who plug it in and call it a day. I believe, strongly, that they have no place in a professionally installed system and I also believe that I’m justified in feeling that way. I have three times in the past month reached out to Apple support for sanity checks and found that their Airport support is nothing short of incompetent. They are literally only able to help in a single device scenario and even there, can only walk you through their poorly designed Airport Utility software….sort of.

Below, I try to outline some of the issues I have with them and why…

Firewall? What firewall? What’s going on in there? Literally no one knows except the engineers in Cupertino and they haven’t shared it amongst Apple’s tech support. This is, in my opinion, the most critical aspect of the device to have visibility of and the ability to adjust and, in the Airport case, we get nothing. No visibility = no trust.

Routing performance seems fine, good even but, we have almost no flexibility in setup. God forbid someone orders CenturyLink’s new fiber service requiring bridging incoming VLANs to prevent double NAT. It isn’t possible and I know it’s coming. VPN? Nope. Internal DNS? Nope. Scripting? Nope? Dynamic DNS updating? Nope? SSH support? Nope. VLAN support? Nope. QoS (Quality of Service) support? Nope. Solid SNMP support? Nope. The list goes on and on.

As for Wi-Fi/WLAN issues…yeah, they’re objectively terrible.

Airport Utility in Windows exposes the option to manually select channels but, only the 2.4GHz radio change will take. The 5GHz will remain in auto. There is also an option to deselect “use wide channels” but, it does nothing (and that’s bad for contentious areas or systems using more than two APs). Per Apple support, that’s “by design”. Wait, the software is “designed” to offer options that don’t affect any change? Yup. The iOS and Mac versions of the Airport Utility will allow channel selection but, will not allow you to use 20MHz or 40MHz channel widths.

Airport Utility in Windows exposes (under network options) the ability to reduce transmission power but, ONLY FOR THE 5GHz RADIO. This is objectively bad as the 2.4 GHz radios create larger cell sizes and we require the ability to reduce cochannel interference in contentious environments or systems using more than three APs (2.4GHz) or two APs (5GHz, due to 80MHz wide channel width). In any case, reducing power in 5GHz doesn’t actually take effect on the radio. Per Apple support, “it’s not meant to”. Wait…..what? I didn’t test iOS (too exasperated) or Mac (don’t carry one) versions to see if they actually work.

RRM (Radio Resource Management) cannot be tweaked in any significant way. The only thing we can adjust is manual channel selection (in iOS, don’t bother opening up your Windows version) and their auto channel selection flat out doesn’t work. For example, I worked on a five AP job yesterday and four of the five APs (all set to auto) were on channel 11  and well within “earshot” of one another. When more than one AP can “hear” another on the same frequency, they have the practical performance of one AP. This is true no matter how many APs are on the same channel and includes neighboring or contentious radios. I was able to use Airport Utility (combined Windows and iOS versions) to make what few changes I could and improved the performance on the client’s WLAN from 3-20Mbps down to >70Mbps (as high as 86) but, with better tools/APs, I could spend less time doing so and get even better results.

In short, I can hold my nose and find a way to “justify” using Airports on projects that have one or two, and in a very few instances, three APs AND are in environments with very little interference from neighboring networks. Anymore than that and we are shoe horning a particularly poor choice into our designs and doing our client’s a disservice.

[end of email removed to protect the innocent]

Update OpenDNS….with a Raspberry Pi!

I don’t know if you’re aware but, there’s porn on the Internet. Lot’s of it. I mean, like, a lot lot. As a father of three, one of whom is entering her teenage years, it was time for me to revisit some DNS filtering using OpenDNS. Sure, I could chain proxy servers on my network and use Dan’s Guardian to help block content but, OpenDNS is just so damned easy to implement and, despite their recent acquisition by Cisco, they’ve done a lot to improve the way we use the web. In other words, I’ve been paying for their Home VIP service for years and intermittently actually implementing it. Recently, I decided to go active with it again.

To use the service is ridiculously easy. Just set up an account (preferably a paid one, support what you use, right?) and point your router at their DNS servers. Easy. Peasy. However, most of us aren’t paying for static IP addresses from our ISP and therefore, our external address can change from once every few months to several times a day. Since it’s our own external IP address that we associate with our OpenDNS account, it’s important that you update their servers when ever our dynamic address changes. If you have either a Windows box or Mac it’s a breeze to install the available IP address updater client thing but, not all of us use those operating systems. No judgement.*

So what’s a Linux family to do? Easy, just install the incredibly lightweight ddclient software (really just a Perl script) on your Linux machine that you leave up full time. For me, this is no big deal. I have a whole slew of Linux servers running all the time. Each of them with more than enough resources to add a simple little script/daemon on. With that said, I wanted to geek this task out a bit and decided to run ddclient on one of my Raspberry Pi devices. I already have a RasPi 1 B+ running Squeezeslave (software that acts as a client device to play music from the Logitech Media Server that currently runs on my Synology NAS) that, frankly, isn’t breaking enough of a sweat. So I decided to add the OpenDNS updater/ddclient software on it and let it work it’s magic. Instructions are here. In order to install, you could likely just use your distro’s package system (apt, yum, pacman, etc.), though. For me, running Raspian (Debian Wheezy), I just run sudo apt-get install ddclient and then walk through the installer. The installer won’t have options to add OpenDNS credentials but, don’t fret. We can make short work of that. Instead, I entered my DynDNS credentials (different service, maybe another blog post) with no intention of actually using them in the ddclient software. Instead, once the install is complete, I just open the config file (sudo nano /etc/ddclient.conf), remove the erroneous account and put in the following…

# Configuration file for ddclient generated by debconf
#
# /etc/ddclient.conf

#opendns
daemon=900
syslog=yes
mail=root
mail-failure=root
pid=/var/run/ddclient.pid
protocol=dyndns2
use=web, web=myip.dnsomatic.com
ssl=yes
server=updates.opendns.com
login=OPENDNS ACCOUNT EMAIL ADDRESS
password=’PASSWORD’
NAME OF OPENDNS NETWORK

Now, note that 1) you’ll need to enter the email account associated with your account, 2) your password must be enclosed in single quotes (‘) and 3) the network you assign in the last name can’t have spaces in it and 4) your OpenDNS account must be set up for dynamic updates through the advanced tab. If, like me, you choose the daemon option (in my case, set to a 900 second or 15 minute interval), you’ll also need to open /etc/default/ddclient and enter similar to…

# Configuration for ddclient scripts
# generated from debconf on Mon Aug 24 19:04:49 MDT 2015
#
# /etc/default/ddclient

# Set to “true” if ddclient should be run every time a new ppp connection is
# established. This might be useful, if you are using dial-on-demand.
run_ipup=”false”

# Set to “true” if ddclient should run in daemon mode
# If this is changed to true, run_ipup must be set to false.
run_daemon=”true”

# Set the time interval between the updates of the dynamic DNS name in seconds.
# This option only takes effect if the ddclient runs in daemon mode.
daemon_interval=”900″

…and then restart the software by running sudo /etc/init.d/ddclient restart. That’s it. You now have an OpenDNS updater running that will update your account with your dynamic, external IP address every fifteen minutes. Super easy and just another way to eak some utility out of something as simple as a Raspberry Pi or other linux boxen you have available on your network.

 

*Scratch that. I’m totally judging you but, trying to stay reasonably polite about it, too.

802.11ac is not the future….Round Two

Here we go again. Another post on the benefits of the newly ratified 802.11AC standard. In my first post I explained modulation and how it applies to the .11AC user. In this post I want to focus on MU-MIMO, Multi User – Multiple Input Multiple Output, and what that brings to the table. In order to do so, we need to first address the older 802.11N’s use of MIMO, sans MU.

So, what is MIMO and why should we care? MIMO, Multiple Input, Multiple Output is best thought of as an enhancement to legacy systems that allows for the use of multiple transmitters and receivers in the access point (AP) and/or client device. In simple terms, the AP or client will utilize multiple radios and antennas. Typically seen in 802.11N are combos such as 2×2 (two input chains and two output chains) or 3×3 (yeah, you guessed it, three input and three output chains). The biggest benefit to these multiple chains is the means by which the throughput is increased by taking advantage of multipath signals.

What in the world is multipath, you ask? Multipath is, in a way, interference. When a signal is broadcast, lets say from a laptop to an AP, it is not sent in a single direction to the AP. Instead, it’s usually broadcast in an omnipolar manner. It travels out in (sort of) all directions.* As it travels towards it’s intended recipient, the signal encounters walls, windows, ceilings, pizza boxes, and more. This signal then reflects away from these obstructions and continues to travel at a new angle. Ultimately, the AP “sees” multiple instances of these reflected signals ,but at ever so slightly different times. In pre .11N systems which were, by definition, SISO or Single Input Single Output, these multiple instances could not be interpreted individually and it adversely affected the receiver’s ability to decipher the true signal from the noise. 802.11N introduced the ability to combine these spatial streams with the use of multiple chains (antenna/radio combos). Combining the signals results in a greater SNR or Signal to Noise Ratio. It was a radical improvement to the 802.11 standard that, in combination with other advancements, increased the theoretical maximum throughput rate in 802.11G of 54Mbps to 802.11N’s potential of 600mbps.

Along comes moo….or is it MU? MU, the Multi User component of .11AC’s MU-MIMO is a continuation of the standard. What MU-MIMO brings to the table, in simple terms, is the ability to utilize multiple antennas for multiple clients. For example, if you have a 3×3 AP and multiple clients attempting to transmit or receive data at the same time, the AP can simultaneously transmit/receive with, say, two of the antenna chains to one client and dedicate it’s third to another client. By using the spatial diversity of the antennas themselves, we can push data without making other client devices wait their turn, increasing overall throughput. Not only do you get the benefits of MIMO and it’s ability to combine diverse spatial streams but, add to that the ability to do so for more than one connection at a time.

All of this does, of course, come at the cost of processing power but, Moore’s Law applies and we see higher and higher quality chip sets in both APs and stations. Another cost to consider is the relative loss in RSSI (Received Signal Strength Indicator) when individual clients, with multiple antennas/chains, don’t get to use the full 3×3 antenna array because another client is using some. This loss in RSSI can and does have a direct effect on the MCS rate available (see my first post on modulation), potentially reducing throughput because smaller bits of traffic can be sent at any given time.

All in all, MU-MIMO is but one more advancement in the AC standard that can allow for higher data rates than now legacy 802.11N. It’s part of the reason why 802.11AC is not the future…it’s here, now and it kicks ass.

 

*Omnipolar isn’t entirely correct. Most antennas are designed to radiate in somewhat of a donut shape, rather than sending the signal out in all directions like a sphere. Many manufacturers can provide the radiation pattern of the APs they offer.

Enable Multicast in UniFi System

Yesterday, we discovered that Lutron is requiring multicast in order to connect to a RadioRA2 main repeater. Why? They couldn’t answer after waiting 20 minutes on hold for service. Doesn’t make sense to me since the station is attempting to connect directly to the repeater’s IP address so it should be a unicast connection. The technical support rep I spoke to didn’t even know what multicast is and suggested….ahem….that the programming laptop connects directly to the repeater via Lutron’s proprietary wireless. Yeah, not so much.  Our onsite technician could connect through the network via Ethernet but not through the Ubiquiti UniFi wireless. So, in order to correct the issue and let him meander the home as he worked, I had to tweak things a bit by doing the following…

1) ssh into your UniFI server
2) determine the site ID and SSID
3) cd /usr/lib/data/unifi/sites/SITEID
4) use nano to create a doc titled config.properties
5) paste the following
config.igmpsnoop_enabled.[SSID]=false
6) restart UniFi server and wait a bit for the change to take effect.

All of that assumes that your UniFi controller/server is running on Linux (mine runs on an Ubuntu 14.04 install at Digital Ocean). If your server is running on something other than Linux….well……fix that.

Easy. Peasy.

 

Punk Rock Makers

Huh? What in the world would make me even consider a blog post such as this? Well, there’s a lot to it, that’s what and the growth of home grown electronics seems, in many ways, to echo the DIY ethos of the early punk rock scene.

In the world at large (and particularly on the Internet), I am witnessing a HUGE resurgence in the DIY, “maker” type electronics space. There is a great deal going on and it’s fascinating to watch. All over the world, people are picking up their soldering irons, booting up their computers, assembling funny little bits of kit and tying it all together in wonderful new ways. Electrons are being manipulated and, for many, new connections are being made. Every day, people are introducing us to their projects and new fangled ways of interfacing both hardware and software on blogs, via Twitter and community forums. It’s a big deal. Just look at the growth of such entities as Make Magazine, Instructables, Hackaday and more.

So what does this have to do with punk? I believe that, in large part, open source hardware and software has been a driving force behind the boost in popularity. Linux distributions, open software/hardware, “hacker spaces”, and more, have fostered a sort of community of makers. Users helping users. Builders improving upon builders. Ordinary folks standing on the shoulders of giants and contributing in their own way. It’s now hip to be a geek much the same way the community of early punks, from London to New York to Los Angeles, fed on one another’s work in the 1970’s and ’80’s and reinvigorated rock and roll.

There is also a vein of rebellious, anti-authoritarian individualism that runs through the DIY community of electronics ans software hackers. Much like Sid Vicious got a new gig with the Sex Pistols when he was spotted wearing a home made “Pink Floyd Sucks” T-shirt, many of the most innovative electronics producers of today are eschewing the big corporate players, a la Microsoft. They’re embracing open (or semi-open) platforms and excelling despite (or because of) that decision. Curiously, like the DIY record labels, fan ‘zines, underground clubs and, hell yes, the bands themselves, that defined the early punk scene, some of the most successful players in the “maker” scene today are doing things their own way and redefining how business can be done. Makerbot, Adafruit, Sparkfun and, yes, even (to some extent) Google. The “gray hairs” are watching and they know that they’re losing market share to, of all groups, their own past customers. That’s right. We’re moving into our garages, home offices and hacker spaces in order to set up our own labs to compete against the suppliers we once supported.

Examples, you ask? Well, I’d say just take a look at the phenomenal success of the Arduinot. This simple little MCU/IDE combo has blown up and folks who would have otherwise never considered tinkering with such gear are finding themselves enthralled. Myself included. The fact that Arduino has made all aspects of the project open, thus spawning imitators, has not hurt them in the least. Rather, they have benefited from it. As we all know, “imitation is the sincerest form of flattery”.

Arduino doesn’t do it for you? Check out the enormous success of big brothers Beagle Bone, Raspberry Pi, and more.

Does this movement represent, like punk rock, a revolution? I think so. You may not have to create the electronics equivalent of “God Save The Queen” or “Blitzkrieg Bop” to enjoy this new paradigm but, you can sure as heck enjoy yourself banging out your own “three chord” masterpiece of LED’s, buzzers, Ethernet, and code…

802.11ac is not the future…

802.11ac is the latest, ratified standard in wireless networking and it is not the future. It is here, now and it rocks.

There are a number of improvents to the existing 802.11n standard that we have been enjoying since it’s ratification in 2009 in 802.11ac. Not the least of which are 256QAM (Quadrature Amplitude Modulation), MU-MIMO (Multi User – Multiple Input, Multiple Output) and, the use of current 80MHz channel widths with 160MHz channel widths coming soon. These three technology refinements make for incredibly efficient use of airtime and allow for massive amounts of data to be pushed over the WLAN. While variations in the number of streams in both access points and client stations, environmental considerations and more significantly affect the potential throughput, we live in an age where it’s possible to push over a Gbps wirelessly!

In this blog post, let’s first look at modulation techniques and advancements and we will address the other benefits of the standard in future installments.

The easiest way to define the benefits of 256QAM is to first look at other, older types of modulation. If you were to go back to the beginnings of Wi-Fi (802.11-Legacy, you would find BPSK or Binary phase-shift keying. When data was transmitted, there were only two, hence binary, symbols or bits that could be sent at any given time. They were either a one or a zero. The process of modulation was much like a man in a crowd translating the 0s to “A” and 1s to “B” and calling out, or broadcasting those translations. The demodulation process was much like another listener hearing, or receiving those As and Bs and translating them back to 1s and 0s. Information is able to be passed but, it’s slow because individual bits are transmitted one at a time.

Next up came QPSK or quadrature phase shift keying which added the ability to not just look at a binary or on/off state but, amplitude as well. When compared to the example above, it would look much like the same man broadcasting, at any given time a “A”, an “a”, a “B” or a “b”. These would then be demodulated not as single symbols or 1s and 0s but as two symbols. An “A” may represent 00, an “a” could represent 01, “B” could represent 10 and, “b” would, in turn, represent 11. There was no more effort or time required to modulate the As and Bs so, we could double the throughput or data carrying capacity of BPSK. Make sense?

As technology continued to be refined and both phase and amplitude were manipulated to send data, we later achieved 16QAM. This was a radical advancement in how data is moved across the Wi-Fi medium of air. It allowed for four symbols to be transmitted at any given time. The easiest way to understand is to study constellation diagrams which are easily found on Wikipedia but, to summarize, using 16QAM, the system is able to send, for example, a single transmission that could represent four digits, like 0101 or 0100. Essentially any variation of 2^4th power. Using our example of a man speaking or broadcasting, it would be like adding to “A”, “a”, “B” and “b” the ability to adjust pitch or frequency. The demodulating listener would hear the difference between a high pitched, squeaky “A” and a low pitched, baritone “A”, allowing for a greater combination to be translated into 1s and 0s. Once again, I ask, does this make sense?

Now that we have covered how the modulation/demodulation process looks in layman’s terms, extrapolate through 64QAM which allows for six symbols or bits (a la 001100 or 010101, or 2^6th power variations) to be transmitted at a time and through to 256QAM which allows for 8 symbols (a la 00110011 or 01010101 or 2^8th power number of variations). Because the system is passing longer variations of bits in the same time frame as older technologies, it’s makes for a  far more efficient use of resources. In the case of Wi-Fi, these resources include airtime and, consequently, you’ll see a benefit in battery life of mobile devices like laptops, phones and tablets. There are significant increases in speed of file transfers which are, for all intents and purposes, what every single data transaction in computing is. For example, loading a web page on your tablet’s browser is really only a request by your device to a server asking for files that reside there to be transferred to your device for viewing. Get it? I thought so.

Now, the last bit on this subject which must be addressed is ECC or Error Correction Codes and they’re effect on MCS (Modulation Coding Streams). Because we’re now packing denser bits of data into transmissions (see Wikipedia for constellation diagrams) and pushing said data at much higher rates, the potential for errors is increased. In wireless systems, these errors can depend on many factors including too high a signal or RSSI (Received Signal Strength Indication. Yes, you read that right…too high. Think in terms of distortion in an audio system when speakers are overdriven), low signal or RSSI, reflections of signal causing “garbled” transmissions and more. I will touch more on MCS rates in the last installment of this series but, suffice it to say that when many different potential bit variations are packed into small spaces, the potential for the receiving device to confuse them is higher, requiring correction or retransmits and, essentially, affecting the efficiency of the system. I mention this because many people new to wireless assume that the data throughput rates marked on the box or in marketing materials are to be expected in real world environments and, in truth, they couldn’t be more wrong.

So, this may be the first time you’ve ever considered the “geeky” nature of modulation rates but, I haven’t even touched on modulation techniques or “vehicles” like DSSS (Direct Sequence Spread Spectrum) or OFDM (Orthogonal frequency-division multiplexing). The point being that when dealing with something as mysterious as an invisible means of moving data, as important as Wi-Fi has become to virtually all of us, as ubiquitous as our wired Ethernet networks, it is a very complex subject and to be examined in it’s constituent parts. What could be more fun than that?

2014 Mikrotik MUM

Having had some time to relax and reflect on the 2014 Mikrotik MUM held in Pittsburgh, PA, the following were my personal highlights…

1) Soft promise release of the new RB850Gx2 by end of this month (Sep. 2014)
I want to get my hands on this board. With dual core PPC architecture, we can move encryption off to hardware. It also sports 512MBs RAM and is available in the same, familiar RB450G form factor. At roughly double the power of the 450G and half the the power of the venerable RB1100AHx2, I believe this will become my new “go to” Routerboard for most projects.

*Edit, this promise came and went. I’m editing here 10/5/14 and, while the devices have now shipped to distributors, they aren’t available here in the States yet.
2) 802.11AC is here (and it’s damn good)
Mikrotik was putting a fair amount of emphasis on their new .11AC offerings and we got to see some in action. Let me tell you, it looked good. Using the bandwidth test tool, they were pushing UDP packets 460-470Mbps using the internal CPU to generate the traffic. That’s crazy good throughput. I’m looking forward to picking up some SXTs or similar to play with in my own lab.

3) Greg Sowell gave a brief, casual talk on AnyCast that was pretty good.
It simplified the idea for me (thinking in terms of CDNs, etc) that made sense. While I have no use for it in my current role, it got me thinking about how regional content delivery works.

4) OpenFlow (on Mikrotik hardware specifically)
I don’t recall the fella’s name who gave this tak but, damn, it was good. I doubt  we’re that many years away from OpenFlow and SDN becoming more popular (one day the norm?) and this was an excellent introduction.

5) www.MikrotikConfig.com
Steve Dischler released www.MikrotikConfig.com to generate address lists, firewall rules and QoS (Queue Trees). It’s a cool, free tool that allows you to enter simple parameters and outputs scripts that can be imported into your local ROS deployments.

*Edit, I have been using this tool to create address lists for a couple of weeks and really dig it.

6) CAPsMAN (Controlled Access Point system Manager)
Uldis from Mikrotik gave us a rundown on CAPsMAN running on ROS/Routerboards. That’s right, using your Routerboard install as your WLAN provisioning and management tool. No need for an additional piece of gear (ZoneDirector, WLC or UniFi controller). It works with all Mikrotik APs (running latest version of 6 series software and the new wireless-fp package). It works via layer 2 or 3 (MAC and UDP) allowing for your WLAN to be managed by an offsite device (I’m thinking of setting up an x86 box for testing this). One thing I will be pushing through support is a request to set allowable 2.4GHz channels when a CAP (Contolled Access Point) is set to “auto” channel mode. As it is now, the AP is going to select the least congested channel and I, like many others, insist on using ONLY channels 1, 6 and 11.

7) www.Macrotick.com

Ummm…wow, these cats are offering both custom Routerboard enclosures (including custom colors and branding) with integrated UPS and dual power supplies and all with a choice of different boards. They are absolutely beautiful with really cool rack mount ears that allow you to set the depth of the router in the rack. They also provide a hosted management solution that looks interesting for those selling managed services.

8) Meeting new people from different industries and locations
Last but, not least, I really enjoyed meeting people from so many different parts of the world and so many different industries. There were attendees from Ghana, Nigeria, Slovakia, Brazil, Latvia, Iraq, Mexico and, of course, all over the United States. I was also introduced to people working in so many different industries and so many diferent disciplines, all using RouterOS and Routerboard products. I was truly inspired by the experience and look forward to pushing myself to learn more and providing ever better installs for my clients.

Your Wi-Fi Sucks…

I’ll bet you bought a single, consumer grade wireless router and plugged it in wherever your modem is with no regard for best signal distribution. I’d wager that you didn’t do any sort of scan for neighboring, contentious APs (Access Points*) and I’ll bet you wouldn’t know what to do with the results if you did. Odds are that you cheaped out and are running wireless in the 2.4GHz RF (Radio Frequency) spectrum only. A hundred bucks says you don’t know that because your wireless system sucks, it’s making your neighbor’s suck, too.

Chances are, I’m right… and you know it.

The last several years have seen wireless networks grow to the point of ubiquitous. Such is certainly the case in urban areas. In that same time, the price to performance ratio has roughly followed the same curve as consumer electronics and computing. Meaning that virtually anyone can walk into a big box store, have some young, zit covered “expert” encourage them to purchase the latest whiz bang router and follow a browser based wizard to set the device up for basic operation. Unfortunately, most people have zero understanding of even the basics and nowhere near enough patience to educate themselves. Instead, they either set up a sub par system that never meets their expectations and leads to frustration OR….they have some “expert” (a co worker, a neighbor, the cable guy or the kid who cuts their lawn) set up a sub par system that never meets their expectations and leads to frustration. Few people are experiencing Wi-Fi the way it should be.

These days, it doesn’t matter if you’re in an enterprise, small business or even residential environment, we all have come to rely on wireless connectivity. The massive adoption of mobile devices has only made us more dependent. However, all too few of us are willing to invest the time, energy or money to leverage the true potential of a damn good Wi-Fi system. So, what is one to do? Let’s look at some easy, basic items and make your Wi-Fi suck less, shall we?

1) It’s High Time You “Modernize”. 

Unless you’re living on acreage or on an unmoored yacht, do yourself a favor and purchase a dual band router or AP/s. The introduction of the 802.11G standard was really the beginning of massive wireless adoption and with it, the overuse of the unlicensed 2.4GHz ISM (Industrial, Scientific, Medical) frequency band. What that means is that inexpensive, 2.4GHz radios are more than prevalent and our shared airwaves are rife with competing, contentious signals. All these Wi-Fi networks are also interfered with by such other devices as Bluetooth, microwave ovens, wireless phone handsets, baby monitors and more. It’s an ugly, crowded band of frequency to attempt to push your video streaming, online banking and cat pics through. The signal to noise ratio is often very low, like trying to hold a clear conversation in the middle of massive crowd of conflicting conversations. Worse, the way that Wi-Fi works is if you attempt to transmit data through this crowded spectrum and portions of that data are “garbled”, the transmission gets attempted again…and again……and again. All the while, your neighbor’s devices are doing the same thing. It’s a problem that gets worse and worse and your wireless performance can be severely compromised.

An 802.11N, dual band router or AP helps alleviate this problem, at least for modern client devices (mobile phones, tablets, laptops and more), by utilizing the higher frequency 5GHz frequency band. While the 5GHz frequency can be more easily attenuated (it doesn’t pass through obstacles as readily as the lower 2.4GHz range) and, thus, your wireless range may be slightly smaller, it is far less congested. This allows for cleaner “airtime” and far fewer retransmissions of data. Jumping into the higher frequency band, where possible, may be the single best improvement one can make in implementing a new Wi-Fi system.

I also highly recommend setting up two SSIDs (Service Set Identifiers, the broadcast name of your wireless networks). One with the name of your choice for the 2.4GHz radio and a second, named the same but, with something along the lines of “Fast” appended to the end. This is a manual form of band steering that really make a difference on how your network performs. Legacy devices will only “see” the first SSID and connect to it while, newer, more capable devices will “see” the 5GHz network and utilize it’s better speed and throughput. Some people name the networks the same, assuming that the client/connecting devices will automagically connect to the better network. Don’t count on it. Since 2.4GHz RF penetrates obstacles better, you may have a very usable signal for the higher frequency radio but, the lower frequency may have as much as 15dB higher signal strength. The laptop or mobile device may then wrongly choose the crowded 2.4GHz SSID and you miss out on the benefits of cleaner airtime.

2) Spend a Little Time Studying Channels and Channel Width. Seriously…Do This. 

Even though I have now talked you into using a dual band device to broadcast your wireless, you likely have legacy client devices (like, say, the iPhone 4/S, Google’s 2012 Nexus 7, many laptops and desktop adapters and more) that don’t have a 5GHz radio included. You will therefore need to broadcast Wi-Fi using both 2.4GHz, for older clients, and 5GHz radios, for newer devices. While there is a lot one can learn about channel use in the higher 5 frequency band, you will NEED to spend time studying how channels and channel width pertain in the lower 2.4 band.

In 2009, the IEEE released the 802.11N specification which allows for both 20MHz and 40MHz wide channels. You can think of channels like water pipes. A wider pipe allows for more fluid to pass in the same amount of time, at the same velocity, as a narrower pipe. The same holds true for our wireless channels but, in this case, it’s data instead of fluid. However, in the 2.4GHz band a 40MHz wide pipe is often detrimental. The last thing you want to experience is Adjacent Channel Interference. Wi-Fi is a shared medium, meaning that the time data is sent over the air is shared with all other devices using it. If you’re in range of other’s systems and on a different, yet adjacent (or overlapping) channel, there is no mechanism for the two to recognize one another and share the time. They simply attempt to speak over one another. On the other hand, if you’re in range of one or more other wireless systems and you’re using the same channel, the cogo systems can “see” one another and will attempt to cooperate. Instead of speaking over one another, raising the Signal to Noise Ratio (SNR), they will back off, using a Guard Interval (a small amount of time used to back off before transmission) to let each other take turns with the available airtime. This is known as Co Channel Inteference (CCI) or Co Channel Contention (CCC). While these nano second guard intervals can slow your network transmissions, they make for a much more efficient use of the frequency and it is far less detrimental to performance than ACI. Far less.

In North America there are 11 potential channels that your wireless can be assigned to. Since channels reside within a narrow frequency range and each channel’s center frequency is only separated by 5MHz, channel width becomes supremely important. There are only three possible channels that can be used without overlap when implementing 20MHz wide channels. These are channels 1, 6 and 11. Because of this, there is never, ever, ever, ever, never a legitimate argument for using any other channel than 1, 6 or 11. Ever. Further, if you are fortunate enough to live in an area without competing networks, you still probably don’t want to use the allowed 40MHz wide channels in the 2.4 range. Why? Because many client devices, Apple products in particular, work very poorly with them. In other words and to keep it simple. You want to ONLY use 20MHz wide channels addressed on channels 1, 6 or 11.

5GHz is a bit of a different animal. Primarily because it is less congested to begin with and secondarily because it doesn’t penetrate and pass through obstacles as well, you’re less likely to be “stepped on” by neighboring devices. Thirdly, 802.11N allows for 40MHz wide channels that work very well in this frequency band, the “fatter pipe” theory allows for a faster transmission of data and more efficient use of airtime. Lastly, there are TWELVE possible non overlapping, 40MHz wide channels**! If you have newer client devices and WiFi devices, you can even implement 80MHz (six safe channels) or 160MHz (two safe channels) with the latest 802.11AC standard. Those, my friend, are FAT pipes.

3) Pay Attention to Your Surroundings. 

Especially in dense environments, like crowded neighborhoods, apartment style complexes or business parks, you are likely to be surrounded by wireless networks. These networks have the potential to virtually decimate your wireless performance if you don’t know what they’re up to. The good news is that even though the RF energy is invisible, the networks aren’t. Using software, you can identify other’s networks and many of their settings. This is because these competing devices are broadcasting “beacons” ten times a second. These beacons are used by client devices to identify and initiate communications with the broadcasting radios. For little to no expense, you can install software on the client device of your choice, whether it be a Mac, Windows or Linux laptop or even your Android mobile device, that will allow you to “see” your neighbor’s WiFi. My personal favorite program for simple scans is inSSIDer from Metageek. I use it prior to installing a wireless network to see what channels and what signal strength adjacent networks are broadcasting at. This allows me to avoid ugly adjacent channels like networks broadcasting on channels other than 1, 6 or 11 or 40MHz wide that, if at a high enough signal strength, will wreak havoc on mine. I also always use appropriate channels but, if possible, try to separate mine from theirs. In other words, if a neighbor has a correctly placed network on, say, channel 1 that has a high signal strength (-65 or higher RSSI, Received Signal Strength Indicator), I may use channel 6 or 11. I also do the same type of separation if I am building a network with multiple APs, using correct channels but, separating by RSSI when I need to reuse channels. This one step alone can make an enormous difference in your system’s performance and, thus, your kitten video viewing.

4) Design/Install for Coverage and Capacity.

This one isn’t so difficult to understand. Don’t assume a single wireless router stuck in a corner of the basement is going to cut it. Not only does your iPad need to “see” a reasonable signal from the router or AP, the router or AP needs to “see” your iPad. The TCP/IP network protocol that you’re using when pushing data across a network is a conversation. Both devices communicate with one another. If your signal strength or signal to noise ratio is too low, it makes for a lousy conversation and performance suffers. Therefore, you may need to relocate the broadcasting radio and/or add more radios to the equation. You may need to experiment with placement while using a simple tool like inSSIDer or more robust (and expensive) tools like AirMagnet Planner or Ekahau Site Survey to determine the best location and whether or not additional radios will be necessary. By no means scientific, I generally shoot for an initial deployment of about one AP per 1,500 sq.ft. in a residential setting. Depending on how many devices will authenticate with the radio, radios used and construction/obstacles, I can always adjust that equation up or down for the best possible price to performance ratio.

Ultimately, it takes only a minimum of effort and, frankly, only a tiny bit of basic knowledge to get more out of your investment in wireless technology. It’s worth it. There is an enormous amount of available information on the subject and differences in vendor technologies can be overwhelming but, you’re not gunning for an RF engineering position here. You just want to eek out every bit of reliability, throughput and speed you can out of service that you will use every single day. I am also more than willing to expand on or answer your questions on these and other options at your disposal. Just reach out.

Your Wi-Fi sucks but, it doesn’t have to.

*Please remove WAP or Wireless Access Point from your vocabulary. It’s an unfortunate, common phrase and it’s redundant. There is only one kind of access point and they’re wireless by definition. Just a pet peeve of mine.

**Assuming your AP and connecting devices utilize DFS channels.