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.

 

 

A Guide to Wi-Fi Requirements.

Do you know what you want, what you really, really want?

Sometimes we need to flesh out real requirements for a Wi-Fi service.  A common request from customers is simply, “Install Wi-Fi at xyz location”.  Actual requirements start with understanding the desired outcome or performance expectations and working backwards from there.

There are relevant questions.  Such as what type of user experience is required and what density of users will be simultaneously using the Wi-Fi service. Or what existing systems does the service need to integrate with?

Business questions first.  If we don’t understand the business reasons for wireless in the first place, we won’t be able to design a solution that meets expectations.  Why is the business investing in a wireless service, what are the required business outcomes and timelines and how will the business measure the success of the installation?  What applications will they run and what type of activities do the business expect users to perform over the wireless medium?

Technical questions that address wireless functionality naturally follow. The customer may have standards that must be followed to integrate a wireless service:  user authentication, encryption, device management, reporting, logging, wireless intrusion detection (and desired responses), application performance, density of users, or different user groups.

From answers to these business and technical questions, we are able to begin noting the Wi-Fi requirements.  The discovery phase will assist here:  identifying supporting infrastructure, is there adequate bandwidth for the solution, is Quality of Service (QoS) required for application performance and which 802.11 standards need to be supported.

During the process of discovery, in some situations we may find that a Wi-Fi solution will not actually be fit for purpose!

The physical environment where wireless service will be installed prompts its own questions.  If site access for an inspection is difficult: a picture tells a thousand words.  A few well-chosen photos of the wireless environment will tell us a lot about what needs further analysis.  The environment will mandate if internal or external (weatherproof) Wi-Fi equipment is necessary, if internal or external antennas will be required, where there may be coverage challenges and so forth.  Physical security of equipment inside the environment should also be taken into consideration.

Site surveys are crucial.  We will want to know if the proposed environment is subject to wireless interference or,  if it has to contend with 50 foreign Wi-Fi networks fighting for the same channel space.  Site surveys can discover useful information that then become technical requirements that feed into the design.  For example, if a site survey uncovers heavy amounts of interference on a commonly used channel by Wi-Fi, then the design can avoid using this channel.

Most importantly: with Wi-Fi it is all about the client.  If the technology the client is using to connect to the wireless infrastructure is poor, then the experience will be poor.  No matter how good the wireless system.  If you have a mixed bag of client devices, old and new, fast and slow; all of this will affect the design.

So tell us what you want.  What you really, really want.