The second is show references, followed by a profile type and name – it will tell you all the profiles that reference the one provided. Very handy if you’re trying to clean up cruft and want to find profiles that are abandoned and no longer useful, or if it won’t let you delete a profile because it is still in use (where it will annoyingly not actually tell you where)
In my previous post, I went over the basics of working from home. It’s worth noting here that many of these concepts can also be applied to your kids who might be taking school online – they’re teleworking just like you are, and face many of the same challenges. In this and future posts, I’ll be dealing with the tech basics required for a successful and productive home office.
I was originally going to do a single post on all things tech, but it started getting lengthy, so I decided to break it down into a couple of parts. This post will deal specifically with external network connectivity.
No surprises here – a decent internet connection is pretty much a given for remote work. One thing that is becoming apparent during this quarantine period is that a whole lot of people have abysmally bad internet connections at home. I’m hearing horror stories from the trenches, from my colleagues and friends who work front-line IT support.
The word “Broadband” is thrown around a lot by ISPs intent on selling you a service package, but what does it really mean? In the United States, the Federal Communications Commission updated their definition of “broadband” most recently in 2015, to mean a connection speed of at least 25Mbps downstream (from ISP to your house), and 3Mbps upstream (from your house to your ISP. But what do those speeds really mean? The FCC also has a handy guide listing what activities require what level of speed.
So your Cable ISP touts their “SuperGigaFast” service with “gigabit” service. Sounds great, right? Not so fast. Cable-based ISPs that come into your house via a coaxial cable use a technology called DOCSIS, which has great downstream speeds, and (usually) abysmally bad upstream speeds. The cable companies originally designed this technology back in the late 1990s when internet usage consisted largely of downloading web pages and sending small bits of control data. This meant that an asymmetrical connection would work great for most users, and they would be able to leverage their existing wiring infrastructure.
Fast forward 25 years to 2020, and cloud-based data storage and teleconferencing and the like mean that you need a lot more upstream speed than you used to. But that hasn’t stopped cable companies from selling “gigabit” packages with a paltry 10Mbps upstream connection. When getting an internet service package for teleworking, your upstream speed should be at least 10% of your downstream speed – because if you saturate your upstream link, it’s going to negatively impact your downstream traffic and limit it. This lets the cable company sell you “gigabit”, knowing full well that they’ll never have to deliver on that promise. They also usually provide really cheap equipment which means your Wi-Fi speeds are going to be limited even more, and they still don’t have to deliver on those gigabit speeds they’re charging you for. If you have the option of a symmetrical connection (usually delivered over fiber optic cable), it will be a lot more functional.
Much of what applies to DOCSIS cable connections also applies to DSL connections from the local telephone company. Make sure you have enough upstream bandwidth to do what you need to do. Also beware of any service that has a data cap – working from home can blow through a data cap in a real hurry.
It’s usually worth investing in your own router – the equipment provided by the ISP is, in most cases, absolute junk. AT&T is notoriously bad about this on both their U-Verse DSL and fiber-based services, and they have it configured such that it’s very difficult to use a “real” router with their service.
And in some places, cable, fiber, or DSL aren’t an option, and you’re stuck with either a wireless ISP or cellular.
The typical internet connection requires a couple of devices. ISPs and telcos generally refer to this as “Customer Premises Equipment”, or “CPE”.
This is the device that interfaces your ISP’s connection with your home network, usually via an Ethernet connection. The term comes from “modulation/demodulation”, which is the process of converting a data stream into a series of electrical signals. This operates between what us network nerds call “Layer 1” (electrical signals) and “Layer 2” (data link). I posted on network layers in this post from 2018, if you want to get into some of the details of those. The modem’s primary function is extending your ISP’s physical network to your house. Before the days of direct internet connections, the data link was established over a telephone line by modulating the data signals into electrical signals in the narrow audio range supported by the telephone system.
Modems can take many forms, and in many cases, your ISP’s modem is integrated into a single device with a router. In the case of cable, you can usually supply your own. In the case of DSL or fiber service (where it’s usually called an Optical Network Terminal instead of a modem) it’s usually provided by the ISP and you won’t get much choice in the matter, although sometimes it’s possible to request a specific type or model.
Your smartphone also contains a modem that interfaces to the cellular networks – it likely uses LTE (4G), but older ones (3G) would use CDMA or GSM, and newer ones (5G) use a few different things, mostly based on LTE. If you need to interface a cellular network to your home network, either as a primary or backup link, there are dedicated cellular modem devices for that (more on that in a moment).
This is the device that connects your network to your ISP’s network. It operates at “Layer 3”, which for the vast majority of people means “the internet”. The internet is nothing more than a whole bunch of interconnected networks. A protocol (known as the “Internet Protocol”, or “IP”) has been in place for decades, specifying how all these networks can talk to each other. Each network is connected to other networks by way of a router (also known as a “gateway”). Its job is to look at traffic that comes in, and decide where it needs to go next. If it’s for another device on a network it’s directly connected to, it sends it directly. For something elsewhere on the internet, it sends it to the next router down the line (usually your ISP) to deal with and eventually get it to where it needs to go. This process usually happens in a matter of milliseconds (you can use the “ping” command to see how long this takes, or “tracert” (windows)/”traceroute” (everything else) to see the path it takes. The whole idea is that you don’t see what’s happening under the hood.
The term “Router” is often misconstrued to mean “WiFi”. This is often because the equipment provided by an ISP or purchased consists of a router, a network switch, and a Wi-Fi access point (and sometimes a modem) all in one box referred to as “the router”.
Owing to a general shortage of IP addresses, your ISP will assign a single IP address (which is unique on the entire internet!) to your router’s Internet-facing connection (the Wide Area Network/WAN interface), and your own network devices (on the Local Area Network/LAN interface) will occupy address space that is defined by RFC1918 as “private” address space (which can not be used directly on the internet, but can be re-used by anyone – in most cases, your network will be 192.168.something, the specifics vary from one devices to another). The router will then perform Network Address Translation (NAT) to move data between the two networks. Most of the time, you don’t need to worry about the details of how it’s set up, although when it comes to troubleshooting, having at least a general awareness of how it’s set up can be useful.
This is a key piece of the network, as it is what decides which traffic is and isn’t allowed. This is critical to providing network security. It is usually integrated into the router. It examines each packet and checks a list of rules (which can be updated multiple times a day to react to ongoing threats) to determine if the packet should be sent along its merry way, or dropped into a deep, dark hole.
The Local Area Network
The router is the transition point from your network to the rest of the internet. I’m not going to get into the details of the LAN for the moment (that’s for another post), but this is where you will connect all your equipment, either wirelessly via Wi-Fi, or via a wire to an Ethernet switch.
Virtual Private Networking (VPNs)
This isn’t really a hardware component, but is usually a key piece of any home office (it sometimes uses dedicated hardware, though). The function of a VPN is to connect you to another private LAN located elsewhere (either physically or just another part of the network.) When working from home, installing a dedicated private network connection between the main office to a home office is cost-prohibitive (although there are some interesting new technologies with 5G that will allow you to connect mobile devices directly to the corporate network, essentially making the corporate network its own cellular carrier.)
Enter the VPN – It uses the public internet to establish a connection to the corporate network, and it builds an encrypted tunnel that allows corporate traffic to pass through securely. Sometimes, this is an application that runs directly on a computer, establishing the tunnel directly to that computer, and sometimes, the tunnel is established by the network equipment you have at home, and it just presents another LAN for you to connect anything to. In most cases, in order to use bandwidth more efficiently, any traffic destined for the internet will go out directly from your router rather than through the tunnel and go out from the corporate network. This is known as a “split tunnel”. Some companies, however, will choose to pass all traffic through the tunnel in order to benefit from high-power corporate firewalls to better secure traffic against malware, data leakage, or to just filter content.
As cloud-based services such as Office 365 become more prevalent, VPN connections back to the office are becoming less important.
It’s worth noting that this is very different from public “VPN” services that claim to offer privacy when accessing the internet. While the underlying technology is similar, all these are doing is relocating where you hop on to the internet, sending it through the VPN service’s network where they can inspect all your traffic.
A quick rundown of connectivity equipment:
If you need to connect to a cellular network, you can use the following:
Your smartphone hotspot (easiest in a pinch, can also usually connect to your laptop via a USB cable if you don’t want to or can’t use Wi-Fi)
A portable hotspot, sometimes called a “Mi-Fi” or a “Jetpack”, both are brand names for common devices in this category. Many of these also can connect via USB.
A USB cellular modem (check your cellular carrier for options)
An Ethernet cellular modem or router such as a CradlePoint IBR series device
Some home routers and most enterprise routers will support a USB cellular modem as a WAN connection, either primary or as a backup.
There is a wide variety of these out there, and most of what you can get commercially will do the job better than what the ISP provides. NetGear and Asus both make devices that perform well, but these devices have limited security capabilities. TP-Link and Linksys are cheap, but tend to underperform. Plan on about $200-300 for these types of devices. I’ll get into this a little more when I talk about the LAN side of things.
Many people recommend Ubiquiti equipment, but that’s a lot more complex than I feel is appropriate for non-technical users. If it’s what a managed service provider supplies, then it’s quite adequate, but make sure they’re the ones that have to deal with the technical side of it. If you’re a network nerd, then you already know this stuff.
This is where your corporate IT department or managed service provider usually comes into play, and provide you with a firewall/router device that is pre-configured for corporate networking and security standards (and will often set up a dedicated VPN connection as well). These devices come from a vendor like Fortinet, Aruba (in the form of a Remote Access Point), Palo Alto, Cisco/Meraki, and other enterprise networking vendors. These are helpful in a home office because they are generally managed by your MSP or IT department and are essentially plug and play, giving you a secure network connection that is functionally equivalent to being on the network at the office.
You can also purchase your own standalone firewall from these vendors, all of which have a home office model or two in their lineup. They usually come with an annual subscription cost which gives you frequent updates to the security profiles and rules, to adapt to the changing network threat landscape. These will typically provide much better security than a residential gateway device, but are more complex and expensive to operate.
This got long (which is why I’m breaking tech up into multiple posts), but the bottom line is that your internet connection is a vital piece of the home office puzzle, and it’s one where you’re going to want to spend some time and money getting it right. If you have to go cheap somewhere, this is not the place to do it, but you also don’t need to go overboard.
One of my favorite things to do when I’m at a Disney park is to play the wireless nerd’s version of Hidden Mickeys: Trying to spot the myriad creative ways in which Disney’s Imagineers have blended their excellent wireless network into the carefully contrived scenery. It truly is magical how they can make wireless everywhere while keeping it nearly invisible.
So naturally, when I’m wearing the wireless engineer hat and have a challenge where I get to flex some of that creativity, I’m all over it.
A few years back, I helped a church in Wichita overhaul their aging and underpowered WiFi by designing and installing a new Ruckus system. Last year, they embarked on a new project to add a chapel to their campus. Naturally they wanted to extend the wireless LAN to this new building.
But… It’s a chapel aimed at doing weddings and other sorts of events, so it was paramount that the wireless equipment not be visible, to maintain clean architectural lines with a minimum amount of obvious tech equipment. Some concessions had to be made for audiovisual, but visible access points were a (network) bridge too far.
After pondering the problem as well as observing drawings and renderings, I happened upon the architectural lighting elements in the plan that were mounted on each of the columns. I dug into the design of these and discovered that they were a pair of LED fixtures concealed inside some finish carpentry with a textured plastic surface. And most importantly, there was an empty space in the middle between the two light fixtures that measured about 20cm square by 40cm high, and centered approximately 8 feet off the floor. Not only was that low enough to keep the APs close to the clients, there was plenty of room to put in one of the Ruckus H510 Wall APs designed for the hospitality market (which I also currently have in my house running Unleashed, although they will soon make way for some of the Aruba AP303H units or their new Instant On AP11D counterpart). I’m a big fan of these in-wall units for many reasons.
I asked the electricians to give me a box and conduit to four of these columns, as well as a pair of data cables. I only planned to use two access points initially, but since running cable would be prohibitively difficult after the buildout, I wanted to keep my options open should capacity needs increase in the future.
After many months of construction (Summer of 2019 was an utterly awful weather summer if you were in the construction business), I finally got the green light to install these. I took a bit of personal time on my way down to another job in Oklahoma for my employer, and executed the plan. I’m pretty happy with the results.
Second in a series about our first deployment of a Mist Systems wireless network.
In my last post, I gave you an overview of the various components of the Mist Wireless system. This post will go into some of the design considerations pertaining to this particular project.
Because we’re now designing for more than just Wi-Fi, there are a few additional things to factor in when planning the network.
It’s not uncommon for your floor plans to have a “Plan North” that doesn’t always line up with “Geographic North”. Usually this isn’t a factor, but looking at it in hindsight, I would strongly encourage you to build your floor plans aimed at geographic north from the start, as the Mist AI will also use that floor plan for direction/wayfinding and the compass in mobile devices will be offset if you just go with straight plan north. You can also design on plan north, but then output a second floor plan file that is oriented to true north. Feature request to Mist: Be able to specify the angle offset of the plan from true north and correct that for user display in the SDK.
For this project, I had access to layered AutoCAD files for the entire facility, which (sort of) makes things easier in Ekahau Site Survey, but sort of doesn’t – the import can get a little overzealous with things like door frames. I had to go do a fair bit of cleanup afterwards, and might have been better off just drawing the walls in the first place. This was partly due to the general lack of any good CAD tools on MacOS that would have allowed me to look at the data in detail and massage it before attempting the import into Ekahau. The other challenge is that ESS imported the ENTIRE sheet as its view window, which made good reporting impossible as the images had wide swaths of white space. Having the ability to crop the CAD file would have been nice.
Since one of the areas being covered is a large auditorium, we had to plan on multiple small cells within the space. We needed to put the APs in the catwalks, as we did not have the option of mounting the units on the floor because of the sanctuary being constructed onslab (and while the cloud controller allows you to specify AP height and rotation from plan north, there is no provision to tell it the AP is facing *up* and located on/near the floor). This posed a few challenges, the first being that we were well above the recommended 4-5m (the APs were at 10m from the floor), the other being that we needed to create smaller cells. For this, we used the AP41E with an AccelTex 60-degree patch antenna.
We also needed to either run a whole lot of cables up to the theatrical catwalks, or place a couple of small managed PoE switches – we unsurprisingly opted for the latter, using two 8-port Meraki switches, and uplinked them using the existing data cabling that was feeding the two UniFi APs that were up there.
As an added bonus, the sanctuary area was built with tilt-up precast concrete panels, which allowed us to use that heavy attenuation to our benefit and flood the sanctuary space with APs and not worry about spilling out too much.
Capacity-wise, we used 10 APs in the space, which seats 1700. Over the course of several church designs, I’ve found that a ratio of one active user for every three seats usually works out pretty well – in most church sanctuaries, the space feels packed when 2/3 of the seats are occupied, which means that we’re actually planning for one client for every two seats. Now, we’re talking active clients here, not associated clients. An access point can handle a lot more associations than it can active clients. As a general rule, I try to keep it to about 40 or 50 active clients per AP, before airtime starts becoming a significant factor.
In an environment like this, you want as many client devices in the room to associate to your APs, even if they’re not actively using them – when they’re not associated, they’re sitting out there, banging away with probe requests (especially if you have any hidden SSIDs), chewing up airtime (kind of like that scene from Family Guy where Stewie is hounding Lois just to say “Hi.”). Once they associate, they quiet down a whole bunch.
In addition to the main sanctuary, there are also a couple of other smaller but dense spaces: the chapel (seats 300) and the East Room (large classroom that can seat up to 250). In these areas, design focused on capacity, rather than coverage.
As is often the case with church facilities, College Park Church is an amalgamation of several different buildings built over a span of many years, accommodating church growth. What this ends up meaning is that the original building is then surrounded on multiple sides with an addition, and you end up with a lot of exterior walls in the middle of the building, as well as many different types of construction. Some parts of the building were wood-frame, others were steel frame, and others were cast concrete. The initial planning on this building was done without an onsite visit, but the drawings made it pretty obvious where those exterior (brick!) walls were. Naturally, this also makes ancillary tasks like cabling a little interesting.
Fortunately, the church had a display wall that showed the growth of the church which included several construction pictures of the building, which was almost as good as having x-ray vision.
Because this is a public space, the visual appearance of the APs is also a key factor – Sometimes putting an AP out of sight takes precendence over placing for optimal Wi-Fi or BLE performance.
Mist specifies that the BLE array can cover about 2500 square feet. The wifi can cover a little more, but it doesn’t hurt to keep your wifi cells that size as well, since you’ll get more capacity out of it. In most public areas of the building, we’re planning for capacity, not coverage. With Mist, if you need to fill some BLE coverage holes where your wifi is sufficient, you can use the BT11 as a Bluetooth-only AP.
Mist recommends placing the APs at a height of 4-5m above the floor, in order to provide optimal BLE coverage. The cloud controller has a field in the AP record where you can specify the actual height above the floor.
Because the BLE array is directional, you can’t just mount the APs facing any direction you please. These APs are really designed to be mounted horizontally, the “front” of the AP should be consistently towards plan north, but the controller does have the ability to specify rotation from plan north in case mounting it that way isn’t practical. The area, orientation and height are critical to accurate calculation of location information.
Several of the existing APs in older sections of the building were mounted to hard ceiling areas, and we had to not only reuse the data cable that was there, but also the location. Fortunately, the previous system (Ubiquiti UniFi) was reasonably well-placed to begin with, and we were able to keep good coverage and reuse those locations without any trouble.
There were also some co-existence issues in the sanctuary where we had to make sure we stayed out of the way of theatrical lighting and fixtures that would pose a problem with physical or RF interference. In the sanctuary, we also have to consider the safety factor of the APs and keeping them from falling onto congregants like an Australian Drop-Bear.
Planning for BLE
Since starting this project, I’ve begun working with Ekahau on testing BLE coverage modeling as part of the overall wifi coverage, and it’s looking very promising. I was able to go back to the CPC design and replan it with BLE radios, and it’s awesome. Those guys in Helsinki keep coming up with great ideas. As far as Ekahau is concerned, multi-radio APs are nothing too difficult – They’ve been doing this for Xirrus arrays for some time now, as well as the newer dual-5GHz APs.
Stay tuned for a post about BLE in Ekahau when Jussi says I’m allowed to talk about it.
First in a series about our first deployment of a Mist Systems wireless network.
Over the course of the past few months, I’ve been working with the IT staff at College Park Church in Indianapolis to overhaul their aging Ubiquiti UniFi wireless system. They initially were looking at a Ruckus system, owing to its widespread use among other churches involved with the Church IT Network and its national conference (where I gave a presentation on Wi-Fi last fall). We had recently signed on as a partner with industry newcomer Mist Systems, and had prepared a few designs of similar size and scope for other churches in the Indianapolis area using the Mist system. We proposed a design with Ruckus, and another with Mist, with the church selecting Mist for its magic sauce, which is its Bluetooth Low Energy (BLE) capability for location engagement and analytics.
Fundamentally, the AP count, coverage, and capacity were not significantly different with Ruckus vs. Mist, and Mist offered a few advantages over the Ruckus in terms of the ability to add external antennas for creating smaller cells in the sanctuary from the APs mounted on the catwalks, as floor mounting was not an option.
Mist is a young company that’s been around for about two or three years, and they have developed a couple of cool things in their platform – The first is what they call their AI cloud, the second is their BLE subsystem, and the last is their API.
Their AI component is a cloud management dashboard (similar to what you would see with Ruckus Cloud or Meraki — many of the engineers that started with Mist came over from Meraki), where the APs are constantly analyzing AP and client performance through frame capture and analysis, and reporting it back to the cloud controller. The philosophy here is that a large majority of the issues that users have with Wi-Fi performance is actually related to performance on the wired side of the network (“It’s always DNS.” Not always, but DNS — and DHCP — are major sources of Wi-Fi pain). The machine learning AI backend is looking at the stream of frames to detect problems, and then using that to generate Wi-Fi SLA metrics that can help determine where problems lie within the infrastructure, and doing some analysis of root causes. An example of this is monitoring the entire Station/AP conversation during and shortly following the association process. It looks at how long association took. How long DHCP took (and if it was successful), whether 4-way handshakes completed, and so on. It will also keep a frame capture of that conversation for further manual troubleshooting. It also keeps a log of AP-level events such as reboots and code changes so that client errors can be correlated on a timeline to those events. There’s a lot more it can do, and I’m just giving a brief summary here. Mist has lots of informational material on their website (and admittedly, there’s a goodly amount of marketing fluff in it, but that’s what you’d expect on the vendor website).
Next, we have their BLE array. This is what really sets Mist apart from the others, and is one of the more interesting pieces of tech to show up in wifi hardware since Ruckus came on the scene with their adaptive antenna technology. Each AP has not one, but *eight* BLE radios in it, coupled with a 16-element antenna array (8 TX, 8RX). Each antenna provides an approximately 45° beam covering a full circle. Mist is able to use this in two key ways. One is the ability to get ridiculously precise BLE location information from their mobile SDK, (and by extension, locate a BLE transponder for asset visibility/tracking) and the other is the ability to use multiple APs to place a virtual BLE beacon anywhere you want without having to go physically install a battery-powered beacon. There are myriad uses for this in retail environments, and the possibilities for engagement and asset tracking are very interesting in the church world as well.
Lastly, we have their API. According to Mist, their cloud controller’s web UI only exposes about 40% of what their system can do. The remainder is available via a REST API that will allow you do do all kinds of neat tricks with it. I haven’t had a chance to dig into this much yet, but there’s a tremendous amount of potential there. Jake Snyder has taught a 3-day boot camp on using Python in network administration to leverage the power of APIs like the one from Mist (Ruckus also has an API on their Cloud and SmartZone controllers)
Mist is also updating their feature set on a weekly basis – rather than one big update every 6 months that may or may not break stuff, small weekly releases allow them to deploy features in a more controlled manner, making it easy to track down any potential show-stopper bugs, preferably before they get released into the wild. You can select whether your APs get the early-release updates, or use a more extensively tested stable channel.
Much like Meraki, having all your AP data in the cloud is tremendously useful when contacting support, as they have access to your controller data without you having to ship it to them. They can also take database snapshots and develop/test new features based on real data from the field rather than simulated data. No actual upper-layer traffic is captured.
note: all prices are US list – specific pricing will be up to your partner and geography.
There are four APs in the Mist line. The flagship 4×4 AP41 ($1385), the lower-end AP21 ($845), the outdoor AP61 ($?) , and the BLE-only BT11 ($?). The AP41 also comes in a connectorized version called the AP41E, at the same price as the AP41 with the internal antenna.
The AP41/41E is built on a cast aluminum heat sink, making the AP noticeably heavy. It offers an Ethernet output port, a USB port, a console port, and what they call an “IoT port” that provides for some analog sensor inputs, Arduino-style. It requires 802.3at (PoE+) power, or can use an external 12V supply with a standard 5.5×2.5mm coaxial connector. In addition to the 4-chain Wifi radio and the BLE array, the AP41 also has a scanning radio for reading the RF environment. On the AP41E, the antenna connectors are located on the downward face of the AP.
The AP21 is an all-plastic unit that uses the same mounting spacing as the AP41, and has an Ethernet pass-through port with PoE (presumably to power downstream BT11 units or cameras). Like the AP41, it also has the external 12V supply option.
This install didn’t make use of BT11 or AP61 units, so I don’t have much hands-on info about them.
It’s also important to note that none of these APs ship with a mounting bracket, nor does the AP have any kind of integrated mounting like you would find on a Ruckus AP. Mist currently offers 3 mounting brackets: a T-Rail bracket ($25), a drywall bracket ($25) and a threaded rod bracket ($40). The AP attaches to these brackets via four T10 metric shoulder screws (Drywall, Rod), or four metric Phillips screws (T-Rail). More on these later.
Each AP must be licensed, and there are three possibilities: Wifi-only, BLE Engagement, and BLE Asset tracking. Each subscription is nominally $150/year per AP, although there are bundles available with either two services or all three. Again, your pricing will depend on your location and your specific partner. Mist recently did away with multi-year pricing, so there’s no longer a cost advantage in pre-buying multiple years of subscriptions.
When the subscription expires, Mist won’t shut off the AP the way Meraki does, however, the APs will no longer have warranty coverage. After a subscription has been expired for two months, Mist will not reactivate an AP. The APs will continue to operate with their last configuration, however, but there will no longer be access to the cloud dashboard for that AP.
This is the internet, so at some point we’ve got to talk about cats. It’s in the rule book. The Internet runs on cats. Cat pictures, cat videos, and… cat cables.
Those of you not familiar with the intricacies of the first layer of the OSI “7-layer Burrito” (Internet old-timers will remember this) are probably blissfully unaware of the gory details of the wiring that makes everything (including wireLESS) work.
Dilbert (April 24, 2010)
So who are all these cats, anyway?
Simply put, it’s an abbreviation for “Category”. The Telecommunications Industry Association (TIA) has adopted a series of specifications over the years defining cable performance to transport various types of networks.
Here’s a quick rundown. We’re gonna get a tech lesson AND a history lesson all rolled into one.
Category 1 (pre-1980)
An IBM “Type 1” Token-Ring connector. Known colloquially as a “Boy George Connector” due to its ambiguous gender. Photo: Computer History Museum
This never officially existed, and was a retroactive term used to define “Level 1” cable offered by a major distributor. It is considered “voice grade copper”, sufficient to run signals up to 1MHz, and not suitable for data of any sort (except telephone modems). You could probably meet category 1 requirements with a barbed wire fence. You laugh, but it’s been done. Extensively.
Category 2 (mid-1980s)
Like Category 1, never officially existed, and was a name retroactively given to Level 2 cable from said same distributor. Cat2 brought voice into the digital age. It could support 4MHz of bandwidth, and was used extensively for early Token-Ring networks that operated at 4Mbps, as well as ARCNet, which operated at 2.5Mbps on twisted pair (it had previously used coaxial cable).
Category 3 (1991)
This is the first of the cable categories officially recognized by TIA. It is capable of operating 10Mbps Ethernet over twisted pair (like ARCNet, Ethernet also ran on coaxial cable in the very early days). Category 3 wire was deployed extensively in the early 1990s as it was a much better alternative to 2Mbps ethernet over coax. This is where the now nearly ubiquitous 8P8C connector (often incorrectly referred to as “RJ45”) came into usage for Ethernet, and it’s still in use nearly 3 decades later. Both the connector pinout and the cable performance are defined in TIA standard 568. Since token-ring networks still operated at 4Mbps, they ran quite happily over this new spec. In 2017, one can still occasionally find Cat3 in use for analog and digital phone lines. The 802.3af Power over Ethernet specification is compatible with this type of wire.
Category 4 (early 1990s)
This stuff existed only for a very brief period of time. In the late 1980s, IBM standardized a newer version of Token Ring that ran at 16Mbps, which required more cable bandwidth than what Category 3 could offer. Category 4 offered 20MHz to work with (which may sound familiar to the wifi folks, who use 20MHz channels a lot). But Category 5 came along pretty quickly, and Category 4 was relegated to history and is no longer recognized in the current TIA-568 standard.
Category 5 (1995)
TIA revised their 568 standard in 1995 to include a new category of cable, supporting 100MHz of bandwidth. This enabled the use of new 100Mbps ethernet (a 100Mbps version of Token Ring soon followed, which also used the same 8P8C connector as Ethernet).
An 8P8C connector, commonly (but incorrectly) referred to as “RJ45”. This has been the standard twisted-pair Ethernet connector for the last quarter century.
Category 5e (2001)
TIA refined their spec on Category 5 to improve the performance of Category 5, to support the new gigabit ethernet standard. It is still a 100MHz cable, but new coding schemes and the use of all four pairs allowed the gigabit rate. IBM and the 802.5 working group even approved a gigabit standard for token ring in 2001, but no products ever made it to market, as Ethernet had taken over completely by that point.
Category 6 (2002)
Not long after Category 5e came to be, Along comes category 6, with 250MHz of bandwidth. This was accomplished partly with better cable geometry and by going from 24AWG conductors to 23AWG. This increased bandwidth allows 10Gbps ethernet to operate on cables up to 55 meters in length.
Category 6a (2009)
This refinement to Category 6 increased cable bandwidth to 500MHz in order to allow 10Gbps ethernet to operate at the full 100m length limit for Ethernet. Categories 6 and 6a will support the new 802.11bt Power Over Ethernet Level 3 (60W) and Level 4 (90W) standards (expected 2018) provided that cable bundles do not exceed 24 cables for thermal reasons.
Category 7 cable. Who would want to terminate that? What a pain!
This one never existed in the eyes of the TIA. It still lives as an ISO standard defining several different types of shielded cable whose performance is comparable to Category 6 (bandwidth up to 600MHz for Cat7, 1GHz for Cat7a). Both these specs were rendered moot by 10Gbps Ethernet operating on Category 6a with standard 8P8C connectors. This cat was so ugly, TIA left it at the shelter.
Category 8 (2017)
The latest and greatest, this cable exists to run 40Gbps ethernet. It comes in two flavors, unshielded as 8.1, and shielded (supplanting the Category 7 specs) as 8.2. This cable has a bandwidth of 1600MHz for unshielded, and 2000MHz for shielded.
So there you have it. The cats that put the WORK in “Network”. And because this is the internet, I leave you with gratuitous kittens.
Recently, there was an excellent blog post from WLAN Pros about “Rules for successful hotel wi-fi“. While it is aimed primarily at Wi-Fi in the hotel business (where there is an overabundance of Bad-Fi), many of the tips presented also apply to a wide variety of large-scale public venue wifi installations. Lots of great information in the post, and well worth a read.
At the 2016 WLPC there was an interesting TENTalk from Mike Liebovitz at Extreme Networks about the pop-up wifi at Super Bowl City in San Francisco, where analytics pointed to a significant portion of the traffic being headed to Apple.
Meanwhile, a few months later at the 2016 National Church IT Network conference, I heard a TENTalk about Apple’s MacOS Server, where I first heard about this incredibly useful feature (sadly, it wasn’t recorded, that I know of, so I can’t give credit…)
With most of the LPV installations I’ve worked on, I’ve found the typical client mix includes about 60% Apple devices (mostly iOS). For example, this is at a large church whose wireless network I installed. (Note that Windows machines make up less than 10% of the client mix on wifi!)
OK, So what?
This provides an opportunity to make the wifi experience even better for your (Apple-toting) guests. Whenever possible, as part of the “WiFi System” I will install an Apple Mac Mini loaded with MacOS Server. This allows me to turn on caching. This is not just plain old web caching like you would get with a proxy server such as Squid, but rather a cache for all things Apple. What does this do for your fruited guests? It speeds up the download of software distributed by Apple through the Internet. It caches all software and app updates, App Store purchases, iBook downloads, iTunes U downloads (apps and books purchases only), and Internet Recovery software that local Mac and iOS devices download.
Why is this of interest and importance? Let me give you an example: A few years ago, we were hosting a national Church IT Round Table conference at Resurrection on a day when Apple released major updates to MacOS, iOS, and their iWork suite. In addition to the 50 or so staff Mac machines on the network, there were another hundred or two Mac laptops and iThings among the conference attendees. The 200MB internet pipe melted almost instantly under the load of 250 devices each requesting 3-5GB of updates. That would have melted even a gigabit pipe, and probably given a 10Gbps pipe a solid run for its money (not to mention bogging down some of the uplinks on the internal network!. Having a caching server would have mitigated this. It didn’t do great things to the access points in the conference venue either, all of which were not only struggling for airtime, but also for backhaul.
Just by way of an example, Facebook updates their app every two weeks and its current incarnation (86.0, March 30, 2017) weighs in at 320MB (the previous one was about half that!), and its close pal Messenger clocked in at 261MB. Almost everyone has those to apps, so they’re going to find itself in your cache almost instantly, along with numerous other popular apps. Apple’s iWork suite apps and Microsoft Office apps all weigh in around 300-500MB apiece as well. This has potential to murder your network when you least expect it. (A few years back, the church where I was working hosted the national Church IT conference that happened to coincide with Apple’s release of OSX Mavericks, and a major iWork update for both iOS and MacOS. The conference Wi-Fi and the church’s 200Mbps WAN pipe melted under the onslaught of a couple hundred Apple devices belonging to the guest nerds and media staff dutifully downloading the updates.)
In any case, check out the network usage analytics from either your wireless controller or your firewall. If Apple.com is anywhere near the top of the list (or on it at all), you owe it to yourself and your guests to implement this type of solution.
The Technical Mumbo-Jumbo
As mentioned previously, a Mac Mini will do the job nicely. If you’re looking to do this on the cheap, it will happily run on a 2011-vintage Mini (you can find used Mac Minis on Craigslist or eBay all day long for cheap), just make sure you add some extra RAM and a storage drive that doesn’t suck (the stock 5400rpm spinning disks on the pre-2012 era Mac Mini and iMacs were terrible.) Fortunately, 2.5″ SSDs are pretty cheap these days. Newer Minis will have SSD baked in already.
You can also happily run this off of one of the 2008-era “cheese grater” Mac Pros that has beefier processing and storage (and also fits in a rack, albeit not in the svelte 1U space the Sonnet box uses). If you have money to burn, then by all means use the “trash can” Mac Pro (Sonnet also makes a rack chassis for that model!).
This is a great opportunity to re-purpose some of those Macs sitting on the shelf after your users have upgraded to something faster and shinier.
Naturally, if you’re running a REALLY big guest network, you’ll want to look at something beefy, or a small farm of them Minis with SSD storage (the MacOS Server caching system makes it quite easy to deploy multiple machines to support the caching.)
Since most of your iOS guests will have updates turned on, one of the first things an iOS device does when it sees a big fat internet pipe that isn’t from a cell tower is check for app updates. If you have lots of guests, you will need to fortify your network against the onslaught of app update requests that will inevitably hit whenever you have lots of guests in the building.
The way it works is this: When an Apple device makes a request to the CDN, Apple looks at the IP you’re coming from and says, “You have a local server on your LAN, get your content from there, here’s its IP.” The result being that your Apple users will get their updates and whatnot at LAN speeds without thrashing your WAN pipe every time anyone pushes out a fat update to an app or the OS, which is then consumed by several hundred people using your guest wifi over the course of a week. You’ve effectively just added an edge node to Apple’s CDN within your network.
Content will get cached the first time a client requests it, and it does not need to completely download to the cache before starting to send it to the client. For that first request, it will perform just as if they were downloading it directly from Apple’s servers. If your server starts running low on disk space, the cache server will purge older content that hasn’t been used recently in order to maintain at least 25GB of free disk space.
If you have multiple subnets and multiple external IPs that you want to do this for, you can either do multiple caching servers (they can share cache between them), or you can configure the Mini to listen on multiple VLANs:
Once you have the machine listening on multiple VLANs, you can tell the caching server which ones to pay attention to, and which public IPs. The Mac itself only needs Internet access from one of those subnets.
The first dropdown will give you the option of “All Networks”, “Only Local Subnets”, and “Only Some Networks”. Choosing the last one opens an additional properties box that allows you to define those networks:
The second one gives you the options of “Matching this server’s network” or “On other networks”. As with the first options, an additional properties box is displayed.
In both cases, hit the plus sign to create a network object:
It should be noted here that this only tells the server about existing networks, but it won’t actually create them on the network interface. You’ll still need to do that through the system network preferences mentioned previously. If you don’t want to have the server listen on multiple VLANs, you can just make sure its address is routable from the subnets you wish to have the cache server available, define the external and internal networks it provides service to, and you should be off to the races. This will provide caching for subnet A that NATs to the internet via public IP A, and B to B, and so on. Defining a range of external IPs also has you covered if you use NAT pooling.
There’s also some DNS SRV trickery that may need to happen depending on your environment. There are some additional caveats if your DNS servers are Active Directory read-only domain controllers. This post elaborates on it.
Is it working?
Click the stats link near the top left of the server management window. At the bottom is a dropdown where you can see your cache stats. The red bar shows bytes served from the origin, and green shows from the cache. If you only have one server doing this, you won’t see any blue bars, which are for cache from peer servers. Downside is that you can only go back 7 days.
On this graph, 3/28 was when there were both a major MacOS and iOS update released, hence the huge spike from the origin servers on Apple’s CDN. Nobody has updated from the network yet… But guest traffic at this site is pretty light during the week. I’ll update the image early next week.
Other useful features
A side benefit of this is that you can also use this to provide a network recovery boot image on the network, in case someone’s OS install ate itself – on the newer Macs with no optical drive, this boots a recovery image from the internet by default. This requires some additional configuration, and the instructions to set up NetInstall are readily available with a quick Google search.
If you want, you can also make this machine the DHCP and local DNS server for your guest network. With some third-party applications, you can also serve up AirPrint to your wireless guests if they need it.
From a guest experience perspective, your guests see their updates downloading really fast and think your WiFi is awesome, and it’s shockingly easy to set up (the longest and most difficult part is probably the actual acquisition of the Mac Mini) It will even cache iCloud data (and encrypts it in the cache storage so nobody’s data is exposed). Even if you have a fat internet pipe, you should really consider doing this, as the transfers at LAN speed will reduce the amount of airtime consumed on the wireless and the overall load on your wireless network. (Side note, if you’re a Wireless ISP, this sort of setup is just the sort of thing you ought to put between your customer edge network and your IP transit)
Of course, you could also firewall off Apple iCloud and Updates instead, but why would you do that to your guests? Are you punishing them for something?
Android/Windows users: So sad, Google and Microsoft don’t give you this option (Although Microsoft sort of does in a corporate environment with WSUS, but it’s not nearly as easy to pull off, nor is it set up for casual and transient users). I would love it if Google would set up something like this for play store, Chromebook, etc, as about half of the client mix that isn’t from Apple is running on Android. You can sort of do it by installing a transparent proxy like squid.
Now, if only we could do the same for Netflix’s CDN. The bandwidth savings would be immense.
(Added November 16, 2017)
As of the release of MacOS High Sierra and MacOS Server 5.4 (release notes), the caching service is now integrated into the core of MacOS, so any Mac on the network can do it, without even needing to install Server. The new settings are under System Preferences > Sharing:
I’ve been spending the past week at the annual Wireless LAN Professionals Conference in Phoenix. This is one of my favorite conferences along with the Church IT Network conference, because I get to spend a couple of days geeking out hard with a whole bunch of REALLY smart people. The amount of information I’ve stuffed into my brain since last Friday is a little bit, well, mind-blowing…
I spent the first 3 days getting my Ekahau Certified Survey Engineer credential. For those who are not familiar with the Wi-Fi side of my consulting practice, Ekahau Site Survey is a fantastic tool for developing predictive RF designs for wireless networks, allowing me to optimize the design before I ever pull any new cable or hang access points. One of the key points that’s been touched on frequently throughout the training and the conference is what was termed by one attendee as the “Sacred Ritual of the Gathering of Requirements”. It sounds silly, but this one step is probably the single most important part of the entire process of designing a wireless network.
In the church world (and in the business world), your mission statement is what informs everything you do. Every dollar you spend, every person you hire, every program you offer, should in some way support that mission focus in a clearly defined and measurable manner. A former boss (and current client) defines his IT department’s mission like this: “Our users’ mission is our mission.” This clearly laid out that in IT, we existed to help everyone else accomplish their mission, which in turn accomplished the organization’s mission.
I’ve had more than a few clients say initially that their requirement is “we want wi-fi”. My job as a consultant and an engineer is to flesh out just what exactly “wi-fi” means in your particular context, so that I can deliver a design and a network that will make you happy to write the check at the end of the process. I can’t expect a client to know what they want in terms of specific engineering elements relating to the design. If they did, I’m already redundant.
Photo: Mitch Dickey/@Badger_Fi
During the conference someone put up a whiteboard, with the following question:
“What are the top key questions to ask a client in order to develop a WLAN design or remediation?”
The board quickly filled up, and I’ll touch on a few really important ones here:
“What do you expect wi-fi to do for you? What problem does it solve?”
It was also stated as:
“What is your desired outcome? How does it support your business?”
This is one of the fundamental questions. It goes back to your mission statement. Another way of putting it is “How do you hope to use the wi-fi to support you mission?” What you hope to do with wi-fi will drive every single other design decision. The immediate follow-up question should be a series of “why?” questions to get to the root cause of why these outcomes are important to the business goals. You can learn an awful lot by asking “why?” over and over like a 4-year-old child trying to understand the world. This is critical for managing expectations and delivering what the client is paying you a large sum of money to do.
“What is your most critical device/application?”
“What is your least capable and most important device?”
“What other types of devices require wi-fi?”
“What type of devices do your guests typically have?”
It’s nice to have shiny new devices with the latest and greatest technology, but if the wi-fi has to work for everyone, your design has to assume the least capable device that’s important, and design for that. If you use a bunch of “vintage” Samsung Galaxy phones for barcode scanning or checking in children, then we need to make sure that the coverage will be adequate everywhere you need to use them, and that you select the proper spectrum to support those devices. For the guest network, having at least a rough idea of what mix of iOS and Android devices the guests bring into the facility can inform several design choices.
“What regulatory/policy constraints are there on the network?”
This is hugely important. Another mantra I’ve heard repeated often is, “‘Because you can’ is NOT a strategy!” If your network has specific privacy requirements such as PCI-DSS, HIPAA, any number of industry-specific policies, or even just organizational practices about guest hospitality, network access, etc., these also need to factor into the design and planning process.
I have one client whose organization is a church that is focused on a 5-star guest experience. What this translated to in terms of Wi-Fi is that they did not want to name the SSIDs with the standard “Guest” and “Staff” monikers that are common. The reasoning for this was that merely naming the private LAN SSID “Staff” would create in a guest’s mind that there are two classes of people, one of which may get better network performance because you’re one of the elect. It’s also a challenge when you have a lot of volunteers who perform staff-like functions and who need access to the LAN. Ultimately, we simply called this network “LAN”. Meaningful to the IT staff, and once the staff is connected to it, they no longer think about it. Something as simple as the SSID list presented by a wifi beacon is an important consideration in the overall guest experience.
“What is your budget?”
This one is so obvious it’s often overlooked. As engineers, we like to put shiny stuff into our designs. The reality is, most customers don’t have a bottomless pit of money, especially when they’re non-profits relying on donated funds. While I’d love to design a big fancy Ruckus or Aruba system everywhere I go, the reality is that it’s probably overkill for a lot of places, when a Ubiquiti or EnGenius system will meet all the requirements.
“What are the installation constraints?”
“Which of those constraints are negotiable? Which aren’t?”
Another obvious one that is overlooked. You need to know when the installation can happen (or can’t happen), or if there are rooms that are off-limits, potential mounting locations that are inaccessible. Areas that can’t support a lift, or areas that you simply can’t get cable to without major work. Aesthetics can be a significant factor for both AP selection and placement, wiring, and even configuration (such as turning off the LEDs). While one particular AP may be technically suited to a particular location, how it looks in the room may dictate the choice of something else.
“What is your relationship with your landlord/neighbors/facility manager like?”
I kid you not, this is a bigger factor than you might think. In an office building, being a good wifi neighbor is an important consideration. If the landlord is very picky about where and how communications infrastructure is installed outside the leased space (such as fiber runs through hallways, roof access, antennas outside the building, extra lease charges for technology access), you may encounter some challenges. If your facility manager is particular about damage, you need to factor that into the process as well. This likely also will come into play when you’re doing your site surveys and need access to some parts of the building.
There are a whole host of followup questions beyond these that focus on the more technical aspects of the requirements gathering, and your client may or may not have an answer:
“How many people does this need to support at one time?”
“Where are all these people located?”
“When are they in the building?”
“Where do you need coverage?”
“Where do you NOT need coverage?”
“What is your tolerance level for outages/downtime?”
… and many more that you will develop during this sacred requirements gathering ritual. Many of the technical aspects of the environment (existing RF, channel usage, airtime usage, interference source, etc) don’t need to be asked of the client, as you will find them during your initial site survey.
If you’re a wifi engineer, having these questions in your mind will help you develop a better design. If you’re the client, having answers to these questions available will help you get a better design.
What questions are important to your network? Sound off below!
If you need a wireless network designed, overhauled, or expanded, please contact me and we can work on making it work for your organization.
Linking today to some great content from another Ian (ProTip: get to know an Ian, we’re full of useful knowledge). Ian Morrish posts about automating a variety of methods of automating A/V equipment using PowerShell. Lots of useful stuff in here.