How to gather WiFi requirements

If we prepare well, an excellent WiFi service and a happy customer should follow.

So what is involved in preparation to deliver an enterprise-grade Wireless service?

  1. Information and Requirements gathering (this blogpost)
  2. Wireless Design
  3. Wireless Deployment & Testing

The below is a list of things I consider are absolutely key to understand before being able to move to the next step: designing the customer’s WiFi service.

The first engagement is usually a sit-down with the customer to understand what they want to achieve by installing an (enterprise-grade) WiFi service; understand their outcome expectations and to flesh out business and technical requirements. A heads up, the ‘outcome expectations’ can be a long conversation, as it should be.

Site Environment. We will discuss the site environments in the first meeting but we still need to get on-premise at some stage. Wall materials, ceiling heights, external and internal interference, numbers and density of users and more. It will entail at least one site inspection followed by one or more site surveys. The outcomes from these site surveys provide detailed information in order that we can plan the design.

Numbers of users accessing the service. How many users? Are the users clumped together in one main area or spread evenly across an area?

Types of applications used over the service. Find out the critical business applications to be prioritised and the resource requirements of these apps.  We will need to estimate numbers of simultaneous users.

Types of technology accessing the service.  Each device has different behaviour and different capability sets when using wireless.  It’s not just about which 802.11 standard it supports.

Existing wireless – some or all of it may need to be removed. If some of the current Access Point placement is going to be maintained, we can re-use the existing infrastructure cabling = cost + time savings. Ta Dah!

PoE switch port availability. Enough PoE (Power over Ethernet) ports to supply power to all Access Points. Some vendors’ Access Points require extra grunt. PoE+ power rather than PoE. Check the customer’s switch fleet to see what is supported.

10GbE port availability. Some wireless vendors use wireless controllers that, in a chosen architecture, will require 10GbE interfaces to be utilised.

Preferred vendor. If customer has one. Some customers or their service providers will only work with a particular manufacturer. Vendor selection impacts the design phase as WiFi vendors diverge in their approach to deliver an enterprise-grade WiFi service.

Backhaul bandwidth. Calculations must consider bandwidth both per individual site and the aggregate to data centres/Internet. If creating an extra 300Mbps of sustained traffic for an event, then perhaps the existing 20 Megabit pipes to the site will not cut it.

Guest service. This sets off its own subset of requirements:

Presentation of the Guest service: some organisations require some legal Ts & Cs to be accepted by a Guest before allowing public access. Some will want to present logos or advertise something in a captive web portal. Some will wish to charge for access.

Where is Guest WiFi to be available in the organisation? Only at head office meeting rooms, only in cafe areas?

Guest on-boarding, security and network access. How do Guests receive their access credentials, how long are they allowed on the network, any bandwidth restrictions? In addition, there maybe separate levels of Guest use depending on the type of guest. Trusted contractor versus general public for example.

BYOD. If using BYOD, hopefully there’s already a framework in place to determine who is allowed to access what, from which device. If the BYOD device type isn’t standardised  then we will make general assumptions about capability and tackle individual issues as they come up.

Security Requirements. This conversation is more about how to authenticate authorised users than type of encryption.

Application Visibility and Control (AVC) and Reporting. If the customer hasn’t had insight into what applications are going over their network before now, then they are in for a treat. AVC also provides the network with the ability to prioritise critical business apps over non-critical traffic, e.g. social media.

Support. Who will support the user community? Are they experienced at troubleshooting WiFi? Is training required?

Management. How the wireless infrastructure will be integrated into the organisation’s existing ICT management toolsets: alerting, reporting, maintenance, asset and lifecycle management.

At the end of this, Network Architects are armed with much of the information we need to begin design. For larger organisations, with multiple locations, it is just the beginning of perhaps months of work of site surveys and site analysis.

Site surveys will always uncover challenges, which is why we do them. At the end of a recent site survey, I found the office tenants below and above my customer were using 80MHz wide channels. Thank you. Thank you for messing up the spectrum for everyone. But also, sorry for what I’m going to do to your 80MHz channels when I turn my 27 APs on.



Plain English Site Survey Reports

Following a wireless site survey, many organisations are sent automated wireless site survey reports in excess of 80 pages.  These tree-unfriendly documents are the result of a click of a button on site survey software which spits out a colourful but massive report in a few seconds.

For a business however, they are about as readable and interesting as a dot matrix printout of line items at a warehouse.  Everyone remember dot matrix printers?

Essentially, an automated site survey report is raw data.  Factual, accurate and…Unhelpful.  It doesn’t tell the business anything.  A business without wireless specialists (the majority) will look at it and still have fundamental questions:

  • The heat maps are all green, so why is my WiFi rubbish?
  • What are your recommendations?
  • Should I be worried, is this normal?
  • Is -50dBm bad?  It sounds bad.
  • What is Channel Overlap? Do we need more of it?
  • This is unintelligible.

It is nice marketing by wireless survey software vendors, to say ‘Hey, just press this button and your job is done; report generated. You can even put your own logo/branding in.’  It sounds good in theory and it actually is a real time-saver.  But, does your doctor hand you a blood analysis report – composed of fun latin names – and leave you to interpret it on your own?

Myself, I created a template in MS Word.  Each survey report is written in plain english, removing jargon wherever possible and customised to address the reason for the site survey in the first place.  For example: to troubleshoot poor performance or to prove a new service works as designed or, a pre-deployment survey of the current environment.

The report’s content is supported by adding screenshots/tables from the survey into the body of the document or as an appendix.  It also avoids sending a 20MB attachment of irrelevant data to my client.

This is my personal way of doing things and so far, customer feedback has been very positive.

In summary, I think if automated reports are going to be used and sent to customer IT managers, then at minimum they should be accompanied by a separate document. A summary in plain english that offers analysis, findings of interest and (if requested) recommendations.






When upgrades are not about technology

While at a customer’s slightly unusual site (let’s just say, heavy machinery with very custom hardware and applications) they suggested upgrading their wireless installation to the latest technology.  Suddenly foretelling an unanticipated event while upgrading – and subsequent disruption to production, a brief look of alarm crept out.

Actually, similar to the somewhat alarmed look my wife gives me when I reach for another piece of cake.  A look that urges one to ‘reconsider’.

The existing solution works fine, quite well in fact.  The known cost and unknown consequences (for now) of such an upgrade activity were a little alarming considering the as yet unproven benefits of a new solution working with their existing custom devices.

Turns out however, the upgrade had nothing to do with improving the WiFi.  Bigger things were happening; which would impact the wireless network.  And while not near end of support, the existing wireless network in some parts is four years old.  So, End-of-Life in accounting terms.  We all know that the bean counters love to have expensive new items to depreciate.

All the customer needed from me at this time was to call out anything they might be missing.  I noted a couple of things for consideration and then basically, got out of the way.

Reminder to self: technology upgrades may not always be about the technology.  They may be just be a side impact of bigger commercial decisions that are going ahead.

As for the wireless installation, don’t know what I was worried about.  Might have some cake to celebrate.

How to get 1.3Gbps throughput over WiFi

Most manufacturers advertise impressive speeds of up to 1.3Gbps (Gigabits per second) for their latest WiFi gear.  That’s pretty quick.

However, WiFi is a half-duplex technology that relies on substantial protocol overhead to transmit and receive. 1,300Mbps is actually only roughly 650Mbps in the equivalent wired domain, the domain that we are used to comparing speed and throughput.  Also, that target of 1300Mbps will not have a sustained throughput rate like a wired connection, it will be decidedly ‘spotty’.

That said, to get 1.3Gbps [half-duplex] throughput on your WiFi, start with a high performance enterprise-grade wireless Access Point (AP) and a modern high performance laptop i.e. minimum of 3x antennas built-in.

Next, we need to remove everybody else’s devices.  Turn off EVERY other WiFi capable device within 100 metres.  This includes all devices outside of your control.  Neighbouring WiFi modems and wireless Access Points, all other laptops, tablets, smartphones, SmartTVs, Chromecast, Apple iSomething, microwave ovens, IoT emitters, baby monitors and so forth.  Nothing else should be left on.

By now, we must be in a cave somewhere.

Next: tune the specific enterprise-grade features on the AP for high-performance.  Left at default parameters out of the box, key settings critical to high performance would not be enabled.

Then (very important): place laptop within 3 metres (10 feet) of the AP.

Alternatively: go to a specialised wireless testing facility where just you and your laptop sit in a special little room that repels all wireless interference (roughly akin to a recording studio with soundproof walls).

Either way, this is the only way that we will come even close to the advertised speed.

Back to the real world.  Undoubtedly, from time to time your laptop may be in an insanely good position relative to the AP and environment and advise that your connected data rate is indeed 1300Mbps.  In the wired world, this would actually be what you are getting.  In the wireless world, this is not what you get.  You get (substantially) less.

Consider the wireless data rate to be similar to the maximum speed on a car’s speedometer.  Your actual speed, will be limited by the traffic and environment around you.  Just like wireless.

Netflix on the business network

While the network is carrying business critical applications, all well and good.  But Netflix and Soundcloud streaming?  They’re usually red flags.

Enter Application Awareness. One of the most useful outcomes from deploying enterprise-grade wireless is obtaining valuable insights into what the network is actually busy doing and the ability to act upon that information automatically.

The network is an asset that an organisation uses like any other tool to run its business.  Having visibility into how that asset is being utilised is of tremendous value.

Application Awareness leads to a higher level of detailed visibility into an organisation’s actual, ground-level operations, of how users are using the network services.  From this a business is able to identify trends, prevent threats, or recognise that it may need to improve the overall service experience e.g. an increase in capacity.

Many enterprise wireless vendors build Application Awareness into their products.  They also make it easy for administrators to enforce a differentiated service based on profiles;  triggered by application sensors built into the product.  When sensors detect a voice call for example, a certain level of network resources can be awarded to it.  When the sensors detect music streaming, the network can be configured to respond to that differently.

The system can generate regular reports on all of the above, including the health of the network.  The information that these reports provide to the business becomes valuable from Day 1 and indispensible in supporting and optimising the utilisation of this business asset.

An organisation that before was somewhat blind to what the Wi-Fi was busy doing, and not entirely sure of how their asset was being utilised, now has valuable insights and an input for future planning.

CWNE Certification – A personal goal

I thought I’d share this goal of mine that I’ve been thinking about, talking about and worrying about for some years now: to become a CWNE, a Certified Wireless Network Expert.  To a wireless network professional, one who specialises in Wi-Fi, this qualification is a big thing, the top of the certification path in wireless networking.

CWNE is the highest certification awarded by CWNP (, the vendor-neutral organisation that administers the CWNP exams and, in a few days time, I’ll formally submit my application.

So I’m close. Last week, I passed the last exam I needed to pass in order to complete the ‘exam requirements‘ part of the formal application process.  I already had the basic exams, CWTS and CWNA, which I took in 2012.  But to apply for CWNE status, you need to pass:

  • CWDP – Certified Wireless Design Professional
  • CWAP – Certified Wireless Analysis Professional
  • CWSP – Certified Wireless Security Professional

With good reason, the most common advice is to take CWAP first, which gives you an excellent base to understanding 802.11 and its inner workings.

My particular exam path was quite the opposite.  In 2013, security was a weakness for me and I needed to turn it into a strength.  So CWSP was my first exam and I studied pretty hard for it.  Passed it first go in March 2014.

Due to some work projects I knew were coming up and would interrupt my plans for studying at the same pace as CWSP, I decided to halve the amount of time I felt I needed for CWDP and sat the exam just a few months later.  CWDP is not an easy exam (well none of them are) but I was particularly surprised by this one.  Anyway, I failed the exam by a question or two.  Twice.  Got it the third time.

That left CWAP and the thought of CWAP quite frankly scared me (which is why I did CWDP second). I was that worried about my ability to remember complex protocol field mappings and modulations; recognise patterns in Spectrum Analysis and memorize 802.11 headers, sequences and operational processes; that early on I decided to do an authorised CWAP course. In Bangkok. I signed up to Globeron’s CWAP course (taught by Ronald van Kluenen) and it was superb.  From that course, apart from the knowledge learned at the course I obtained two key takeaways: first, an official  CWAP course notebook which is chock-full of impressive tips and notes, and second: self-confidence.  During that course I realised that I was not as far off being prepared for CWAP as I thought I was. It was a massive confidence boost.

Due to work commitments, it took a year for me to prepare and finally sit the exam and happy to say it was last week that I took it and passed.

I would like to mention that all of the CWNP books (published by Sybex) have been superbly written. They really, really have and my hat goes off to the authors of each book.  The books explain technical concepts extremely well. You still need more material though. Luckily there are blogs by CWNEs and whitepapers by universities that are a wealth of information.

Colleagues often ask me why not go for a vendor certification?  Xirrus, Aerohive, Cisco, Aruba, Ruckus, HP all offer their own wireless certification tracks. While these are all valuable in their own right, for what I wanted to achieve, I decided early on for a globally recognised, independent certification.  It suited me for two reasons:

  1. I wanted to focus on learning the IEEE 802.11 standard and how it is applied in the real world in different environments.
  2. I required a flexible, adaptable skillset that could be applied to any situation to troubleshoot issues and audit complex scenarios on any customer implementation, regardless of their chosen brand.

Some curious colleagues (and the odd customer) have also asked me about the Wi-Fi tools I use.  Well, below is what I use but there are lot of awesome tools out there and I would have them all if I could! Principally I use:

  • Tamosoft Tamograph Site Survey (Site Survey software)
  • Tamosoft CommView for Wi-Fi (WiFi Layer-2 Analysis software)
  • Metageek Chanalyzer Pro and a 2.4/5GHz Metageek WiSpy dBx adaptor (Spectrum Analysis)
  • A custom Toshiba Portege laptop that is very thin and extremely light – when walking around sites for hours, you need something that isn’t heavy!

Plus a bunch of other networking tools I’ve used since CCNP and CCIE R&S days.

In summary, from Day One I have wanted – and I truly desire to be, an independent expert.  To be able to offer my customers the best solution for their needs.  While this may be one vendor for one environment, as a consultant I would (and do) recommend another vendor for a different environment which I feel best matches my customer’s current and future requirements.

Getting to this point has been a worthwhile journey.  I have learned an incredible amount of VALUABLE information that helps me every single day of my job.  My networking background has been routing and switching and although it is a job I enjoyed, it was always ‘a job’.  However, wireless and radio frequency operation fascinates me and its not just a job. I’m passionate about it.

To date, it has been an exceptionally rewarding experience.