HP Buying Aruba?

hplogoTwo things happened today. First, Twitter blew up at some point with rumors of HP in talks to buy Aruba. Second, my shares of Aruba stock shot up about 20%. I was disappointed with the first and pleased with the second. Of course, they were directly related.

 
In Case You Weren’t Aware…..
 
HP has had some issues over the past several years. Not so much issues with their technology, which has always been good, but more so with execution. The latest attempt to right the ship has been to split the company into two distinct entities. Trim the fat off of the corporate monster so to speak. Or, maybe a better way to put it is that HP wants to become less of an “all things to all customers” type of company, and more of a “some things to some customers” type of company. Some customers will be served by one of the two HP companies, and some customers will be served by the other, or both. This allows more focus in certain areas, and focus is never a bad thing.
 
Why Does It Matter If HP Buys Aruba?
 
Although this is all speculation, allow me to continue down this road of “speculation”. I realize that neither HP nor Aruba have confirmed any of this. This is probably someone telling someone else something they weren’t supposed to tell. That person tells someone else, and next thing you know, it ends up as an article on a finance site. We all tweet about it and fuel the frenzy, along with the investors who look at balance sheets and run up the stock price of Aruba. By the time it is all over, people will form opinions based on a mix of facts and rumors and one side will have you believe the CEO’s of both companies drown kittens in their spare time. Or, those in favor will have you believe that God almighty came down from heaven and helped to broker this deal. Hopefully, we all end up somewhere in the middle.
 
To answer the question of why it matters, I have to look at it from differing points of view. The first is that of a shrewd business person. The second is that of a technical person who likes the world of technology, and especially Wi-Fi. These are MY views and mine alone. As always, I could completely misrepresent each position and could be completely wrong. I could also be right. Time will tell, and the Internet never forgets, thanks to archives. :)
 
Business View
 
Money. That’s it. Spare me the idealism and desire to do good for the world one widget at a time. Profit-based companies exist to return value to their shareholders, be they public or private. Jobs and philanthropy are a secondary benefit. If you are public, there are a lot of people in expensive suits poring over your books and demanding answers to why you came in at 1 cent below expectations for the quarter. Business is war, make no mistake. Pretty it up with other terms, but the goal is always market domination because that returns the most bang for the buck. Why start a profit-based business if you don’t think you have what it takes to succeed? Nobody wants to work into their 80’s just to pay the rent. We all want to retire and enjoy the fruits of our labor in our twilight years.
 
If, and this is still an “if”, Aruba sells to HP, it is for money. Aruba’s shareholders, and I am one of them, get paid. HP gets a good company with good technology, and thus, they get paid as well. The Aruba portfolio and client list will strengthen HP in the wireless arena. They are already selling Aruba wireless gear today, so it isn’t like Aruba is completely foreign to HP. Of course, so is Dell. Aruba also has semi-partnerships with Brocade and Juniper. As my friend Tom points out:
 


 
From a business perspective, this means that HP can compete a LOT more with Cisco, who teeters around the 50% market share in regards to wireless. If HP can buy Aruba at a decent price, I would say the business folks would be okay with that. Don’t ask me what a decent price is, but my guess is somewhere north of 2 billion USD.
 
Technology View
 
Aruba has good wireless technology. Ignore the silly marketing videos from Aruba and Cisco where they are smashing and drowning access points, and consider that if Aruba’s technology didn’t work, they wouldn’t be the number two player in the enterprise market. There isn’t enough lipstick in the world to put on a pig to give it that kind of market share.
 
If the technology is good, and HP buys Aruba, what is the problem? I submit to you that it is going to be a problem of execution on HP’s side. Take a look at what they are doing in wireless. Does anything stand out? How many HP wireless customers do you know of? I know they are out there. That much is true. What I can tell you is that in the 3 and a half years I have been with my current employer, I have come across one HP wireless install. It was for a school system in the area I live in(Nashville,TN). Just one. I realize that I have not been to every company in the world. I have not seen the networks running thousands of HP wireless access points. I have seen plenty of Aruba and Cisco wireless installs. I’ve come across Aerohive, Ruckus, Ubiquiti, Meraki(pre-Cisco), Extreme, and even SonicWall. In the wild, I have found AirTight, Meru, and Brocade(Motorola), but never HP.
 
Perhaps I am looking in the wrong places though. Your mileage may vary. Perhaps all you see is HP wireless installs. I HAVE seen, and worked on, plenty of HP ProCurve switches. There’s lots of those around. I just haven’t seen much HP wireless out there.
 
Back to the present day HP wireless though. Can you think of anything that sets HP apart in the wireless field? Can you describe them the same way you would Ruckus, Aerohive, or even Meru as it relates to technology that sets them apart?
 
In my mind, their wireless marketing is non-existent. You never see them out there. You never hear about them. Wireless companies with much smaller market share and marketing dollars are out there spreading their message constantly. Whether it is in social media or at technical events, they are out there. Perhaps I am in a bubble though. I fully accept the fact that I may be in a social media bubble as it relates to technology, and all of my peers that I interact with are focused on just a handful of vendors, or in some cases, just one. That is a possibility.
 
Let’s assume I am not in a bubble though. Let’s just assume that my reasoning is sound. When I think of wireless companies, I don’t rank HP in the top 5. That is not a dig on their technology. Not at all. To me, it is a matter of focus. I had the same problem with F5 dipping into the firewall space, and Riverbed dipping into the load balancer space(Sold to Brocade, by the way.). Brand recognition is important. What a company is known for is important, and changing people’s perceptions of that takes time and a whole lot of marketing.
 
When I think about HP buying Aruba, I see nothing but a slow death for Aruba’s product set within the HP machine. I fully expect them to get sucked up into a much larger corporation and get beat down with more corporate bureaucracy. I hope I am wrong though. I don’t think I am the only one who expected Meraki to get sucked up into Cisco and slowly killed off from a corporate culture standpoint. I have been surprised at how long Cisco has let them run as is, but with the Meraki founders leaving Cisco recently, maybe it wasn’t as it seemed.
 
Closing Thoughts
 
If Aruba sells to HP, I hope that they continue to flourish. I hope that they are allowed to keep doing what they do today in terms of customer and partner engagement. I can tell you that Aruba is a good company to partner with from a technical perspective. The local Aruba team my company is engaged with are good folks. There is never a problem with providing whatever hardware we need to be successful. Training has been forthcoming as well. Aruba also has a really visible online and marketing presence.
 
I also hope that HP is serious about succeeding in the wireless arena. I hope that they use the goodwill that Aruba has and make their presence felt in the market. Maybe in a few years, HP will be a name that I hear people mention when considering wireless vendors.
 
I say all of this with consideration of the fact that the overwhelming majority of wireless work I do these days are with Cisco implementations. I’m typing this post in a hotel after finishing another Cisco wireless survey. I like Cisco wireless. It’s a good product. It works. The management piece is a whole different animal. :) I also like Aruba. Maybe a better way to put it is that I like competition. It makes all vendors better. If one vendor dominates a space too much, I think the wireless market as a whole suffers. While I hope that I am wrong with Aruba going off to die in HP, I can’t help but think that Cisco is all too happy to see this acquisition happen, if the rumors are true. Based on the previous years of HP missteps, I can see why this could be a good thing for Cisco.
 
I would love to hear your thoughts. Am I missing anything? Completely wrong?
 

 
Posted in aruba, hp, wireless | 1 Comment

Cisco Wireless Transmit Power Control

Power substation outside a VERY large data center in Atlanta,GA.

I’m going to start out by telling you something you probably already know. Every vendor has their own way of doing things. Sometimes it makes perfect sense, and other times you end up scratching your head wondering why that particular vendor implemented this feature or product. Since I have been spending a lot more time on wireless these days, I came across an issue that forced me to reconsider how transmit power control(TPC) actually works in a Cisco wireless deployment. I thought I would impart some of this information to you, dear reader, in the hopes that it may help you. If you spend a lot of time inside Cisco wireless LAN controllers, this may not be anything new to you.

The Need For TPC

If you have been around wireless long enough, you have probably dealt with wireless installs where all of the access points(AP) were functioning autonomously. While this isn’t a big deal in smaller environments, consider how much design work goes into a network with autonomous access points that number into the hundreds. It isn’t as simple as just deciding on channels and spinning all the access points up. You also have to consider the power levels of the respective access points. Failure to do so can result in the image below where the AP is clearly heard by the client device, but the AP cannot hear the client since it is transmitting at a higher power level than the client can match.

AP-TransmitPowerProblem

 

Now consider the use of a wireless LAN controller to manage all of those APs. In addition to things like dynamic channel assignment, you can also have it adjust the transmit power levels of the APs. This can come in handy when you have an AP fail and need the other APs to increase their transmit power to fill the gap that exists since that failed AP is no longer servicing clients. I should point out that proper design of a wireless network with respect to the client transmit power capabilities should NEVER be overlooked. You ALWAYS want to be aware of what power levels your clients can transmit at. It helps to reduce the problem in the image above.

There’s also the problem that can arise when too many APs can hear each other. It isn’t just about the clients. Wireless systems which adhere to the IEEE 802.11 standard are a half duplex medium. Only one device can talk at a time on a given channel. Either a client or the AP will talk, but not both at once. If an AP can hear another AP on the same channel at a usable signal, the airtime must be shared between those APs. Depending on the number of SSID’s in use, this can dramatically reduce the amount of airtime available for an AP to service a client. You can see some actual numbers with regard to SSIDs and APs in this blog post by Andrew von Nagy.

As you can see from two quick examples, there is a need to control the power level in which an AP will transmit. On controller based wireless networks(and even on the newer controller-less solutions), this is done automatically. I wouldn’t advise you turn that off unless you really know what you are doing and you have the time to plan it all out beforehand.

The Cisco Approach

On wireless LAN controllers, TPC is a function of Radio Resource Management(RRM). The specifics can be found here. I’ll spare you the read and give you the high points.

  • The TPC algorithm is only concerned with reducing power levels. Increases in power levels are covered by Coverage Hole Detection and Correction algorithm.
  • TPC runs in 10 minute intervals.
  • A minimum of 4 APs are required for TPC to work.

It is the last point that I want to focus on, because the first two are pretty self explanatory. The reasoning behind the 4 AP minimum for TPC is as follows:

“For TPC to work ( or to even have a need for TPC ) 4 APS must be in proximity of each other.  Why? Because on 2.4 GHz you only have three channels that do not overlap… Once you have a fourth AP you need to potentially adjust power down to avoid co channel interference.   With 3 APS full power will not cause this issue.”

Those are not my words. They came from someone within Cisco that is focused on wireless. Since that person didn’t know I would publish that, I will not name said person. The explanation though, makes sense.

***Update – It appears that the Cisco documentation regarding TPC is a bit murky. Jeff Rensink pointed out in the comments below that TPC will also increase power levels. Although CHD will increase based on client information, I didn’t use any clients in my testing, as Jeff rightly assumed. The power increases I saw once I started removing AP’s from the WLC could not have been attributed to CHD adjustments. Read his comment below as he makes some very valid points. The NDP reference and accompanying link in his comment is fairly interesting.

Let’s see it in action to validate what Cisco’s documentation says.

TPC Testing

I happen to have a Cisco WLC 2504 handy with 4 APs. I set it up in my home office and only maintained about 10 feet separation from the APs. Ideally, I would test it with the APs a lot farther apart, but I did put some barriers around the APs to give some extra attenuation to the signal. I also only did testing on the 5GHz band. I disabled all of the 2.4GHz radios because I don’t need to give any of my neighbors a reason to hate me. Blasting 5GHz is less disruptive to their home wireless networks than 2.4GHz is due to the signals traveling farther/less attenuation of 2.4GHz vs 5GHz signals/antenna aperture. :)

Here you can see the available settings for TPC in the WLC GUI. This particular controller is running 7.6 code, so your version may vary.

TPC SettingsSome notes on options:

    • You can either set TPC to run automatically, on demand, or at a fixed power rate on all APs. TPC is band specific, so if you want different settings for 2.4GHz and 5GHz respectively, you can have that.
    • Maximum and minimum settings for transmit power are available. The defaults are 30dBm for maximum power and -10dBm for minimum power.
    • The power threshold is the minimum level at which you need to hear the third AP for the TPC algorithm to run. The default is -70dBm. You can set it higher or lower depending on your needs. High density environments might require a level stronger than -70dBm, with -50dBm being the strongest level supported. If you don’t necessarily need to run things like voice, you might be able to get away with a weaker threshold, but you cannot go beyond -80dBm.

A Quick Sidebar on Maximum Transmit Power in 5GHz

I set up the WLC with 3 APs active on 5GHz only. You can see that the power levels on the 3 APs are set to 1 in the image further down, which is maximum power according to Cisco. While it seems odd that max power would be a 1 and not some higher number, consider the fact that there are multiple maximum transmit power levels depending on which UNII band you are using in 5GHz. As a general reference, 20dBm would be 100mW and 14dBm would be 25mW. You could get 200mW(23dBm) of power using a UNII-3 channel vs UNII-1, which is maxed out 32mW(15dBm). That is a HUGE difference.

      • UNII-1 power levels for channels 36-48:
        • 1 – 15dBm
        • 2 – 12dBm
        • 3 – 9dBm
        • 4 – 6dBm
        • 5 – 3dBm
      • UNII-2 power levels for channels 52-64(I didn’t test UNII-2 Extended, but I suspect it is the same:
        • 1 – 17dBm
        • 2 – 14dBm
        • 3 – 11dBm
        • 4 – 8dBm
        • 5 – 5dBm
        • 6 – 2dBm
      • UNII-3 power levels for channels 149-161:
        • 1 – 23dBm
        • 2 – 20dBm
        • 3 – 17dBm
        • 4 – 14dBm
        • 5 – 11dBm
        • 6 – 8dBm
        • 7 – 5dBm

To see the supported power levels in terms of dBm on 5GHz, you can run the following command on the CLI of the WLC:

show ap config 802.11a <ap name>

The output will look something like this after you go through a handful of screens showing other stuff:

AP Power Settings

 

 

***Update – Brian Long wrote a blog post on this very thing! You can read it here.

Back To The Testing…

You can see in the image below that with 3 APs active, they are all running at power level 1, which is the default when the radios come online.

3AP-MaxTXPower

So let’s see what happens when I add the fourth AP. If our understanding of TPC is correct, we should see the power levels come down since the APs are so close to each other and will have a signal strength of well above -70dBm between each other.

4AP-MaxTXPowerThe fourth AP now shows up, but the power levels are still maxed out at 1. The AP’s are also using channels on all 3 UNII bands, so there is a huge disparity in output power right now. After a few minutes, the following shows up in the WLC:

4AP-PowerRedux-1Now we can see TPC working. It has reduced all 4 APs to a power level of 2. Once the TPC algorithm kicks in, it will run every 10 minutes until it reaches a level where the fourth AP is just within the power threshold of -70dBm. Let’s see if it keeps reducing power.

4AP-PowerRedux-2Now we are at a power level of 3. Ten more minutes pass and I see the following:

4AP-PowerRedux-3Two of the APs have been reduced to a power level of 4. Ten more minutes passed and power levels reduced even further. At that point, I powered off one of the APs to see if the power levels would go back to 1 since there was no longer a fourth AP. I didn’t get a screen shot in time to see all 4 APs at an even lower power level, but when I did grab a screen shot of the 3 remaining APs, one of them had been dropped to a power level of 5. I believe this happened prior to my unplugging the fourth AP.

Note – Power level decreases happen in single increments only, every time the TPC algorithm runs(every 10 minutes). To put it another way, it downgrades by 3dB max each cycle. Sam Clements pointed out to me via Twitter that when power levels increase, it can happen much more rapidly since the Coverage Hole Detection(CHD) and Correction algorithm is responsible for power increases.

4AP-PowerRedux-4I waited for at least 30 minutes to see if the power levels would return to 1 for the remaining 3 APs, but they didn’t move at all. They stayed just like the above image.

If you want to see this work on the CLI in real time, you can issue the following command:

debug airewave-director power enable

After I had waited for over half an hour, I decided to power off one more AP. When I brought it back online, I saw all 3 of the APs slowly go back to a power level of 1. Here’s the first change I saw in the 3 remaining APs:

3AP-AlmostMaxPowerAnd then shortly afterward, I saw them back at max power.

3AP-MaxPowerAgain

 

It’s All In The Details

For wireless surveys, my company uses the Ekahau Site Survey product. It is a really neat survey tool and we use it for on site assessments as well as predictive surveys. When you define the requirements of the project, you can choose from a bunch of different vendor specific scenarios, or general wireless scenarios. I can apply those requirements to a predictive survey, or an on site survey where I am trying to determine if the existing coverage/capacity is good enough for the business needs.

Here’s a screen shot of the default requirements for the “Cisco Voice” scenario found in version 7.6.4 of Ekahau’s Site Survey program:

EkahauRequirementsPay careful attention to the “Number of Access Points” field. By default, it shows 2 APs with a minimum signal strength of -75dBm. If I am building a predictive survey for Cisco voice, I would need to have all of my coverage areas to see 2 APs at a signal of -75dBm or better. That’s perfectly fine, but I also have to consider the APs and how they determine, you guessed it, transmit power. If I change the value in the “Number of Access Points” field to 3 APs at -70dBm or better, I can build my predictive survey around inter-AP communication as well. In that scenario, I am not looking to cover the entire floor or building to that standard. I just need to make sure that all of my APs can see 3 or more APs at -70dBm or better. Of course, if I am not using Cisco wireless to support a Cisco voice implementation, I need to figure out how that other wireless vendor determines transmit power. Just something to consider when interpreting the results of an actual or predictive survey. It isn’t entirely about the clients and their relationship to the AP. AP to AP communication matters as well!

Closing Thoughts

Understanding how the TPC function works is pretty important when designing Cisco wireless networks. Failure to consider what all is involved in regards to transmit power on your APs could(not WILL, but COULD) lead to problems in the wireless network’s operation. However, if you want to manually set transmit power, that’s an option as well. Opinions differ on running RRM. I’m not sure there is a right or wrong answer. It depends. :) I will say that I almost never see Cisco wireless implementations where RRM is not being used.

I don’t want to end this post without mentioning that some networks may be perfectly fine running APs at max power, especially on the 5GHz side. Your coverage may be enough to where there is minimal channel overlap(easily achievable in 5GHz with 20MHz channels and the use of all 3 UNII bands), and each AP can hear one or two neighboring APs at a decent level due to good cell overlap. You just might not have enough APs to trigger the TPC algorithm to run. That doesn’t mean “you are doing it wrong”. If it works for the business and all your users are fine, who am I to tell you that you need to “fix” it.

Hopefully this was beneficial to you if you needed a clearer understanding of how Cisco’s TPC function works. If you already have a good understanding of TPC and managed to read this far, feel free to shame humiliate correct me in the comments.

 
Posted in cisco, wireless | 11 Comments

The Importance of Product Education

brainI learned something new this afternoon. While other users of this product were already aware of it, I was not. This is something that is specific to the Wi-Fi community, but there is a larger point affecting all practitioners of technology that I will attempt to illustrate in this post.

The Problem

I have been doing a lot of wireless surveys lately. These particular surveys have been large enough to require two engineers to be on site. We’ll divide up the location by floors or sections in order to get the job done in less time. These particular surveys are in place assessments, so we aren’t putting survey AP’s up on poles and measuring signal strength, determining attenuation of walls, etc. We’re simply measuring the signal of all AP’s in place and making recommendations based on the requirements of the business(e.g. moving to support voice at 5GHz or location based services). In addition to using a survey tool, which in our case is Ekahau’s Site Survey, we are also doing spectrum analysis at various points within the given facility with Metageek’s Wi-Spy DBx hardware and Chanalyzer software.

The spectrum analysis portion is where my problem resided. I happen to have a pair of Wi-Spy DBx devices that Metageek was kind enough to give me when I attended a few Wireless Field Day events put on by the folks at Tech Field Day. Not too long ago, the capability of capturing 2.4GHz and 5GHz simultaneously with multiple Wi-Spy DBx adapters was added. This meant that if you had 2 of their Wi-Spy DBx adapters, you could capture spectrum on the 2.4GHz and 5GHz bands at the same time. If you only had one adapter, you could only capture on a single band at a given time. This meant that when you wanted to capture spectrum in one location, you had to run a capture on 2.4GHz, and then run another capture on 5GHz. If you are doing 5 minute captures, your total time in that spot was 10 minutes, because both bands needed to be observed.

For the past several months that I have been on the road doing surveys, I was able to capture spectrum in half the time of any of my colleagues because I used both of my Wi-Spy DBx adapters at once, where the standard survey kits we were using only had one. Considering the time savings involved while doing spectrum(a decent sized facility might require spectrum analysis in well over a dozen locations) with multiple adapters, we looked into purchasing more Wi-Spy devices for our survey kits. Metageek has a Wi-Spy device that is only 2.4GHz. Since the Wi-Spy DBx can do both bands, we could just purchase the 2.4GHz model and save a little money. As luck would have it, Metageek doesn’t list the price of the 2.4GHz model on their website and asks you to contact them for pricing. I reached out to them this afternoon and received a quick response back.

As of Chanalyzer version 5, you can now record simultaneously in both bands with a single Wi-Spy DBx device. Granted, with a single adapter, it is alternating between 2.4GHz and 5GHz, so it isn’t as granular as it would be if you were using dual Wi-Spy adapters, but still, that is a great feature. If there is persistent interference, that isn’t a problem, but if the interesting spectrum traffic is brief, perhaps it could be missed, or less accurate than if you were using 2 adapters.

I ended up telling the Metageek person who responded to me that we wouldn’t need to buy additional adapters based on this newfound knowledge. While that is a lost sale for them, we did just buy another survey kit that included another Wi-Spy DBx and Chanalyzer license, so they got some additional business from us. :) I should also point out that the person I was communicating with at Metageek didn’t try to push the sale anyway. They were just happy that my “problem” was resolved and made sure to tell me that Metageek made awesome products, with which I happen to agree!

I Don’t Use Metageek’s Products. Why do I care?

The larger point I want to bring up is that of vendor education. Or, to put it another way, ensuring that we as practitioners are up to date on all the features that a given product supports.

Think about the products you use in your daily job. How knowledgeable are you on what the latest software or hardware revisions improve or add? If it is a large list of products, I am willing to bet there are a fair amount of things you could be doing with those products that you aren’t. Some of those things might save you a lot of time and/or money. How valuable is your time? I can’t help you with the endless meetings you may have to endure. I can’t reduce your commute time. I can’t get you more money in your paycheck. What I CAN say is that as your proficiency increases in a given product, you will become more effective in your job, and that is rarely a bad thing for you or the company you work for.

How Do We Keep Up To Date?

Simply put, you have to schedule product update research into your routine. This is especially crucial in any sort of implementation team, be it corporate or VAR. I fully expect the vendors are going to be up to speed on all the latest features of their products, unless you happen to work for a very large vendor like Cisco where a field sales engineer has to be able to sell for the full product portfolio.

This is much easier when you have a team of engineers/admins/architects as opposed to being the sole person responsible for your area of technology. Make a list of the products you have to use in your day to day job and divide that list up among the team. Task them with going over release notes, product data sheets, vendor blog posts, etc. Once they have combed through those things, get the team together and update each other on those products. Some things can be as simple as an e-mail sent out to the team. Other things are better presented in person so that everyone on the team can talk about them and how it affects the operation or implementation of that particular product.

Closing Thoughts

It is easy for me to say that every team should get together and discuss the latest and greatest regarding all of the products they support or implement. It is a LOT harder to make that happen. In this particular case with Metageek’s spectrum analysis platform, our problem was solved quickly, and without additional expense to the company. However, I have experienced the opposite several times in my career.

There are so many different people and projects that eat up portions of your days and weeks. We tend to put professional development to the side in most environments because it isn’t “billable”, or doesn’t appear to make the company any more money. I would argue the opposite. Being able to perform at a high level in your day to day job and not make mistakes out of ignorance ends up benefiting the company immensely in the long run. For many of you, this happens after hours when you are “off the clock” so to speak. There are plenty of things I try to stay current on, but I have to admit that those things don’t encompass all the things I do in my day job on a regular basis.

What do you think? Is it possible to stay current on all the things you do in your job on a day to day basis?

 
Posted in career, learning, training, wireless | 3 Comments