WiFi6 Ratification: Not So Fast My Friend

There has been a lot of publicity lately about WiFi6 obviously and even more visibility when the WiFi6 certification was announced September 16. So now we officially have WiFi6 and we can move on. NOT SO FAST.

Over the past few weeks I seem to be having the same conversation in-person with people as well as in Slack rooms, etc. around this announcement. There is a perception that once this announcement was made it is a done deal and we have 802.11ax as a ratified ammendment now. This is most certainly NOT the case. The announcement that was made in September was around the WiFi Alliance certification occurring not ratification. Well, those are the same thing, I can hear some of you saying. They are not, and this is where the marketing and big money companies come into play.

The WiFi Alliance is a group of companies that pay for the privilege, from USD$5,150/year to be a contributor up to USD$20,000/year to be a contributor according to the WiFi Alliance membership page (https://www.wi-fi.org/membership). According to the Who We Are page:

WFA Who

 

Basically the WiFi Alliance is a group of companies, including Apple, Cisco, Intel, Qualcomm, etc. that pay to work together on collaboration within the industry, testing equipment in labs to verify devices function ‘properly’ and advocate for spectrum usage, etc. In other words, a WiFi marketing company on how devices connect and function. But, this makes it a standard right?

Just as in wired networking and many other industries, the IEEE is the standards body that develops, writes and ultimately ratifies standards for wireless networking in working groups. The 802.11 working group within the IEEE are the ones responsible for publishing the standard, not the WiFi Alliance. This is where the confusion comes in for most people.

The working group puts together the draft of the new technology, then creates publishes this draft. For 802.11ax this draft was not fully completed and approved by the working group until February 25, 2019 according the IEEE website (http://www.ieee802.org/11/Reports/802.11_Timelines.htm). And from the working group timeline we still will not have ratification until at least September of 2020 with final approvals not coming until November of 2020.

Standard

So as we hear in the media and online that WiFi6 is here and certification is complete, let’s not lose site of what that actually means. Is WiFi6 here, yes it is. Devices are beginning to be released at a quicker pace, especially now that certification is complete. Wireless vendors have been out pushing these new APs for a time now and there is beginning to be an install base for them, but nothing too pervasive at this time. Within the wireless community the sentiment is that there are not going to be any large changes, if any at all, before ratification takes place. However, we just need to be careful about going around spreading the word that the WiFi6 standard is published and ratified. There is still another year of work for that to be reality.

What is the Perfect Wireless Design?

Perfection is always something we hear a lot about but we know is almost impossible to achieve. The perfect game in baseball, an undefeated season, completing Super Mario Bros. with a single life. It is hard to get there, but a few have over the years. But what makes the perfect wireless design and how do you go about doing it?

Wireless designs and deployments are as varied as the engineers that do them. Those of us that have been doing this for 20 years or more are definitely set in our ways and have our little tricks and trade secrets on how we look to do configurations, etc. We all have our ways we stick with, RRM configs for Cisco, antenna combinations for stadiums, making pretty designs in Ekahau. All of this adds to our diversity as individuals. This has never been more apparent than sitting in a room with more than a dozen of the brightest at Ekahau Masters while having 30 minute debates over simple things. But that is what makes our industry and community so special. We can have people from 3 different manufacturers, people from competing service organizations and just strong personalities in general and still all come together, disagree vehemently with one another and then have a drink afterwards and laugh until we cry. If all of this is the case and this group of people cannot even agree how can we actually put a box around what a perfect design is?

I think our friend Sam Clements puts it best with the most well known quote in the industry, “It Depends”. A perfect design depends on so much. Yes the RF and physics are important, but what about the other issues we are trying to solve for? Did we capture the customers requirements and actually listen to what their problem is and what their version of success looks like? Did we make the least-capable device work properly?

If you keep up with the community I am sure you have heard Keith Parsons tell you at some point or another that if you meet the customer requirements then it is a success. You do not have to deploy the latest and greatest of everything all the time to make this true. Just because a customer comes to you and says they need to have an ax network, do they really? Our jobs are to help them understand what is out there, how wireless actually works and then listen to what their problems are and advise them on how to deploy a system to address those problems.

I know this sounds like blasphemy, but think how many times you have seen something on BadFi or in life in general and said you could have done that so much better. But do you know the requirements or constraints the customer put on the engineer? There have definitely been times I have installed something in a way I was not happy about, but I had limitations put on me by the customer around aesthetics, etc. and had to do the best I could. Same goes for designs and configurations, I may look at a config someone else does and say, What the hell were they thinking. But, I was not in the meeting with the customer to get the requirements for the network and to hear what problem they were looking to solve. When I meet with a customer for during a kickoff for a remediation or a new network I always ask the same questions, and I may repeat a couple because during the course of those meetings you may get different answers from the customer, or new things may come up that were not apparent to them or to you at the beginning. This is where we start to design the perfect wireless network.

There is a lot of discussion these days about what number CWNE someone is, or what version of the IE are you studying for. I am all for certifications, but don’t make the mistake of putting your knowledge and understanding ahead of the customer’s needs and what they are actually looking to do. In my opinion when you do that, no matter how ugly that baby may look to others, you have created the perfect wireless network. Because it was for that customer and that customer alone.

Security is the New Standard

Everywhere we look today we hear about hacking of servers or email systems, credit card systems being compromised and public Wi-Fi as a ‘use at your own risk’ service. With all of the  big bad’s out there, security should be the new standard within wireless.

Security is more than a buzzword

There are so many buzzwords in the industry at this point with 5G, WiFi6, OFDMA, WPA3 and so on, security should not be considered one as well. For years wireless security was nothing more than a rotating passphrase, if someone remembered to change it. WEP finally got hacked which gave way to WPA and then WPA2. But for the most part all devices where still using a passphrase that was proudly displayed on a white board, sandwich board or the like. When wireless was a ‘nice to have’ commodity this was just fine. With wireless now becoming the primary medium for access, security is a must. Data moving back and forth from private and public clouds requires data have better security than a passphrase. Certificates, central authorization and accounting has become a must. Centralizing these needs into a single system makes securing and monitoring devices within these data sensitive networks.

How can this go further within the network?

Taking security to the next level

Basic monitoring of security within the network, user logins, MAC authentications, machine, authentications, failures, etc. is great to keep up with what is happening or to troubleshoot when a user is having an issue. But with the risks in today’s networks, both wired and wireless, a deeper-level of understanding and monitoring is needed.

This is where a User and Entity Behavioral Analytics (UEBA) system comes into play.

The basics of a UEBA seems simple, but it is a very complicated process. Multiple feeds being provided by items such as packet capture and analysis, SIEM input, NAC Devices, DNS flows, AD flows, etc. all come into the system and are correlated against rules that setup by the security administrators. As this traffic comes in and is analyzed by user a score is provided to that user based on where they are going on the Internet, traffic coming in and going out to ‘dangerous’ locations (i.e. Russia or China), infected emails that were opened, etc. This score is then updated or times. Once customized thresholds that are configured by the administrators are met or exceeded different actions can be taken on that device, disconnected from the network, quarantined on the network, or an alert sent to an administrator.

Total Package

Designing and deploying networks with complete 360º security visibility is no longer an option but a must. With data flowing in and out of private and public clouds, into and out of Internet-based applications, and the pervasiveness of wireless as a primary access medium there has never been a more important time to make security a standard and not an after thought.

WiFi 6 Why We Need It And What It Isn’t

Wireless networks have been around for a long time. We all know the history of the industry starting as a nice to have feature that we could work without a cable. Today wireless has become the primary medium for connectivity in most industries and most households. As the shift has occurred, wireless technology has had to try and keep up. The latest phase of this race is the 802.11ax, or WiFi6, amendment.

Why do we need WiFi6?

By now everyone has heard that 5G is coming and the crazy fast speeds that it will bring from a cellular-side. We will look at that more in another post. But WiFi is fighting the same issues as cellular in today’s world. We are oversubscribed on WiFi, speeds suffer because of older technology, wireless is the primary connection method of almost every device in the world and IoT is coming. Enter WiFi6.

To be upfront as we begin this, ratification of the 802.11ax standard looks to be at least a year away with most stating a date of September 2020 before this will happen. Even without full ratification manufacturers are starting to put out access points and a few clients are starting to trickle into the market.

So with ratification still a year away, why do we need to worry about WiFi6 now? WiFi6 is more about capacity than speed. As more and more devices are accessing the wireless network, bottlenecks begin appearing. The way WiFi6 will handle this is a trick taken from the cellular industry with OFDMA (Orthagonal Frequency Division Multiple Access. The easiest way to explain it is we are taking a highway that has 8 lanes today and then funnels to a one lane road. Huge bottleneck occurs and all traffic grinds to a halt like the 405 in California. Now with WiFi6 and OFDMA, those 8 lanes stay 8 lanes and traffic can flow freely. With having these extra ‘lanes’ capacity is now increased. This is the key part of WiFi6. There is a great white paper on the traffic lanes with well done diagrams and more information on here (https://www.arubanetworks.com/assets/so/SO_80211ax.pdf ).

We have all heard about the speeds and how fast we can now send and receive traffic on WiFi6, but capacity is the key to the system. More capacity equals more opportunities for devices to be serviced on the network, especially for time-senstive data like Voice and Video over WiFi. As we move to Mobility First workplaces and stop pulling cables to desks, wireless is more and more important. Design is ever more complex now for wireless and how we can use the spectrum smarter to allow more of these devices to function and function well.

As stated previously, the key to the new ammendment for 802.11ax is not all about speed. It is about capacity. We need to be looking at how we handle these time-sensitive data and not how we push them faster. With WiFi6, yes the speed is there if you have the right client, but how do we service that least-capable device and make that function as if it is a WiFi6 device? Capacity is the key and as we continue to add more devices, i.e. IoT, wireless first deployments, nurse call devices. WiFi6 is the key to solving this issue and granting that capacity we so badly need.

Auto-Channel Timing and the Issues it can Cause

All wireless network vendors have some Auto-RF Management of some manner, RRM for Cisco, AirMatch (Formerly ARM) for Aruba, etc. Most of the industry uses these features for about 95% of their installs to handle power level changes, channel changes based on interference or utilization. But something I have noticed time and again is the number of installs that use the default values for these Auto-RF algorithms to run.

So the question is, why do we care about this?

When using this for control of power I typically do not see a big issue in using default values for timing of the algorithm. However, for channel assignment I have seen lots of problems over the years using defaults values and the issues it can cause clients.

What is auto-channel management?

Simply, auto-channel management is exactly what it says, centralized automatic management of the channels being used in the network by an RF or mobility master. Each manufacturer has their own way of managing and handling these changes but the concept behind it is universal. We will look into each manufacturers way of doing it in another blog. This one is simply how it generally works.

During normal operation of the wireless network access points collect data about the RF environment, either from dedicated sensors, off-channel scanning, RSSI values that clients are being seen at, as well as neighbor messages from surrounding APs in the same RF group or neighborhood. This data contains client load, interference seen from radar, microwaves, Bluetooth or other networks in the surrounding area.

All of this data gets sent back to the RF Master, typically the wireless controller on the network or a master controller that is handling these duties. This master then takes all of this data to make the calculations for the APs in the network for an optimized channel plan to help mitigate interference as much as possible.

Once this data is compiled on the master the changes are sent back to the network based on anchor times and interval settings. Cisco does this default every 10 minutes starting at midnight. Aruba sends this at 5 am local time to the Mobility Master by default. A common misconception I have run into over the years is just because RRM runs every 10 minutes, does not mean that the channels are necessarily changing every 10 minutes.

 

Why is this an issue for clients?

With the addition of 802.11h the Management Frames Information Elements now include Element ID 37 for Channel Switch Announcements as shown below from the IEEE.

             
  Element ID Length Channel Switch Mode New Regulatory Class New Channel Number Channel Switch Count
Octets: 1 1 1 1 1 1

The Channel Switch Announcement is sent from an AP that has been marked as needing to change channel by the AutoRF calculations. The important parts of the element are the Channel Switch Mode, New Channel Number and Channel Switch Count.

The Channel Switch mode informs the clients on the AP that is scheduled to change channels that a change is going to occur. If this value is set to 1 the clients should cease transmitting data to the AP until the change has occurred, which will cause a disruption in communication for a short period until the change is complete. If the value is set to 0, there are no restrictions on the clients transmitting during the channel change.

The New Channel Number is pretty basic, this the new channel that AP will be on after then channel change is complete.

The Channel Switch Count is basically the countdown timer for the channel switch.  If the count is set to 0 the channel change could occur at anytime. If it is some other number, that is the remaining time before the change occurs.

So with this very basic overview, why does it matter to a client?

In wireless networking a client’s channel is based on the AP it is connected to. If the client is connected to an AP on channel 11, the client will communicate on channel 11. But again, why does this matter?

When an AP changes channels based on RRM calculations, every client associated to that AP must change as well. So our AP that was on channel 11 changes to channel 6 now every client associated to that AP need to change to channel 6 based on the Channel Switch Announcement and the values within that element. Based on the Channel Switch Count, if a client is downloading a file, making a video call, or just doing basic online tasks from their computer there would be a disruption to that client. It could be very brief, but it depends on how long it takes the client to reassociate or roam to the new channel for the AP. With time sensitive applications this can seem like jitter or lag or even just slowness on the network. This can equate to the dreaded, “The network sucks right now”.

Back to the opening, if the defaults time is set to use say 10 minutes, there is a possibility that a network that is seeing interference from surrounding wireless networks, high channel overlap, lower RSSI values, etc. could change channels on AP that frequently. So clients that are connected to these APs are changing channels as well every 10 minutes which could be confused for a small service disruption or just poor network quality. This topic will be looked at in-depth in a coming post.

In the next post we look at some other issues this constant changing of channels can produce as well as how a couple of different manufacturers handle AutoRF within their products.

 

Cisco RRM Restart

Recently when working with Cisco wireless networks I have been really working to get Dynamic Channel Assignment tuned in and really understand much more about it. Some of the important things to make sure you are setting correctly include Anchor Time, DCA Interval (please don’t use the default, there is a blog post coming about that), etc.

One thing that became an option via CLI in the 7.3 code train was the ability to restart the RRM DCA process on the RF Group Leader. Why is this important I can hear some of you saying, or why would I want to do this? Here are a couple of examples of why.

If a controller enters or leaves an RF Group or if the RF Leader leaves and comes back online, as in a reboot, DCA will automatically enter startup mode to reconfigure DCA regardless fo the settings that have been changed on the controller, i.e. not using default of 10 minute intervals. But is there a need to do this manually? Yes.

As you add new APs into the network it is a good idea, and a Cisco recommendation, to initialize DCA startup mode. The reasoning behind this is as APs are added, DCA needs to rerun calculations and provide a more optimized channel plan based on the newly added APs and what the other APs are seeing over the air. When this command is run, it should be done from the RF Leader and will only affect the RF Leader.

The command should be run on both 2.4 GHz and 5 GHz radios:

2.4 GHz: config 802.11b channel global restart

5 GHz: config 802.11a Chanel global restart

802.11ax The Future Begins

The networking industry is full of buzzwords and hype; A.I., M.L., SDWAN and virtual everything. This is even more evident in the world of wireless networking; claims of speeds up to 1 Gbps, wired-like connectivity, mobility first, future-proofing and on and on. It all reminds me of one of my favorite Queen songs Radio Gaga, “All we hear is radio ga ga, Radio blah blah, Radio, what’s new?”.

The new 802.11ax amendment (not yet standard, thanks TheITRebel), or WiFi6 as it is now being called, is slated to be ratified later in 2019. This is causing all kinds of hype in some circles and not so much in others yet as end-user computing devices will probably not have chipsets to support 802.11ax until maybe the end of 2019. Looking forward, more full adoption will probably not happen until 2020 or even as late as 2021.

What is 802.11ax?

802.11ax will build on the features that the 802.11ac, or WiFi5, standard gave us as well as adding some cool new things to help with the ever growing demand on wireless networks. From a desire for mobility-first networks [to cellular offloading that is wanted (and sometimes needed) from the carriers,.11ax has it’s work cut out for it.

802.11ac gave us some significant improvements with additional channel widths in the 5GHz space to allow for 80MHz channels in Wave 1 and 160MHz channels in Wave 2, giving higher bandwidth availability to user devices if those devices had the chipset to support it. The drawback isnow with 80MHz and 160 channels is that we take the available 5GHz channels from a total of 24 down to 5 or 1 available non-overlapping channels, depending on the usage of DFS channels. This makes it much harder to channel plan in an enterprise or LPV style of deployment, so I still recommended to use 20 MHz channels, or perhaps 40MHz if done properly. However, when this style of deployment is done the whopping 1.3Gbps that is touted by the marketing folks cannot be met even when using 3×3 spatial streams. Again, an example of more hype that really is not too useful outside of a small business or home deployment.

802.11ax can achieve throughput speeds of up to 4.8Gbps according to the data sheets and marketing put out so far. But how can we get to those speeds?

As with 802.11ac, to reach the speeds marketing is telling us about we need two things, multiple bonded channels and clients that can support it. Let’s look at these one at a time.

802.11ac wave 2 began to support 160MHz channels as well as Multi-User Multiple Input/Multiple Output to support multiple streams of data. This implementation yielded multi-user downlinks from the AP to the client. However, uplink traffic from the client to the AP is a single client at a time, by contrast. 802.11ax looks to improve this by allowing MU-MIMO APs to talk bi-directionally to up to 8 devices simultaneously and to become almost ‘switch-like’ (I know more buzzwords, sorry). The new standard will also allow capable clients to take full advantage of MU-MIMO and to use dual-streams to an AP which would potentially double the bandwidth to that client.

The best analogy I have seen of this so far is with 802.11ac there is an eight-lane road, that funels down to one-lane creating a bottle neck and allowing only a single car thorugh at a time. This is how MU-MIMO worked previously with legacy uplink/downlink mechanisms. Now with 802.11ax that one-lane road is extended to a full eight-lanes, eliminating the bottle neck and allowing traffic to flow freely.

More to come on this subject soon.