WHAT YOU NEED TO KNOW BEFORE YOU DEPLOY A HIGH CAPACITY,
SECURE WIRELESS NETWORKING SOLUTIONS
1.Overview
Recent Surveys stated
that “80% of new wireless networks will be obsolete within 18 months due to
lack of proper planning.” Your challenge is to build a wireless solution that
will support your organization for many years to come. This document will give
you some things to consider before you select the technology and put together
the wireless deployment plan. We’ve compiled this information from years of
experience planning, deploying and supporting large scale wireless
infrastructure (we consider large scale 100+ access points), we hope this will
help.
2. Radio Frequency (RF) Planning
The first thing to consider when deploying wireless is
regarding Radio Frequency (RF) and where you want to provide wireless access.
It’s not as easy as just broadcasting a strong signal for devices to associate
to. You’ll have many different types of devices, users and areas to cover in a
large scale environment. You’ll need to consider three key things: Coverage,
Capacity, and Performance.
2.1. Coverage: These are the areas
where you want users and devices to be able to attach to the wireless network.
It’s important to know: ·
Where do you need RF Coverage? (both indoor and outdoor) and · How much throughput do
you want to set as your benchmark? For example, you want coverage in building A
to be at least 180 Mbps. You’ll need to define the areas that you want users to
be able to attach to your wireless network. Also define the areas that will
need to support large numbers of users for capacity planning
2.2. Capacity: Each wireless access
point can handle a certain number of wireless clients or devices connecting to
the network. This means that you need to consider the areas that may present a
high number of users, which means the deployment in that area is more
important. Often, an organization will overlook things like classrooms, large
meeting rooms, nurse’s stations, etc. These are high user density areas that
present major issues if not planned properly.
2.3. Performance: Knowing a little
about your RF environment will go a long way in helping to plan an optimal
WLAN. This is where a site survey can come in handy. A site survey will uncover
RF occurring already in your environment and advise accordingly. For example,
if your site is already saturated with 2.4GHz RF then moving your clients to
the 5GHz spectrum might be advantageous. Also knowing how much bandwidth will
be needed to accommodate the applications and clients that will be using the
WLAN is also important. With 802.11ac offering the highest levels of
performance and scalability, it is advised to explore going with high speed
rather than legacy WiFi for all new deployments.
3. Applications and Devices Knowing what devices and
applications will be running over the wireless network is helpful in planning
for the WLAN. Voice and video are two very demanding applications for a wired
network much less a wireless one. Knowing the resource requirements of these and
other applications intended for the WLAN will provide useful measurements for
the planning of the network. If you’re reading this, then you are most likely
planning what we call a “multi-media grade WLAN”, which is to say you need the
system to handle anything you want to put on it. We recommend creating a list
of applications and devices you’ll need to operate on the network and assigning
an order of priority to the applications and devices. The system should be
engineered to support the most mission critical applications first. For
example, your Nurses’ wireless VoIP phones will take priority over the wireless
internet access for your guest users. Having these priorities will help design
the wireless system effectively.
4. Security In the past wireless security was considered to
be inferior to wired security. This is no longer the case. Most often the
wireless implementations can integrate with directory services, allowing you to
control access at the user level. Here are some considerations to make when
thinking about how to implement the highest level of wireless security possible
today.
4.1. Wireless Intrusion Detection
& Prevention - WIDS is the acronym we use in reference to Wireless
Intrusion Detection and Prevention. WIDS is very helpful in being proactive
with wireless security. An integrated WIDS system in your WLAN can detect and
prevent varying degrees of attacks and hacks that are used to acquire access to
your network. It is also useful in something as innocuous as the dreaded “Rogue
AP” which is installed by well meaning, but poorly informed employees seeking
to gain mobile freedom in the workplace.
4.2. Roles and Policies- It helps
to think of your user groups in terms of what they need access to. Then
consider creating a Security Policy that limits their access to only those
systems. An Executive Role would include a Security Policy that allows them
access to the financial servers, while an Employee Role would have limited
access to sensitive servers.
4.3. Directory Services
Integration- Integration with your directory services is a critical step to
provide wireless security by being able to authenticate each user connecting to
the network. The credentials created for each person inside your directory
services should also be used to authenticate the user on the wireless
infrastructure so that you have one database of users accessing the network.
4.4. Role Based Access Control-
RBAC is the process of being able to assign a specific security role (for
example: Employee) to a user or groups of users that connect to the network. In
order to do this your system must have directory services integration and then
be able to assign a Role to that user.
4.5. Wireless Firewalls – Your
system needs to be able to segment traffic by user groups similar to the way a
LAN firewall segments VLANS. For example, a guest user should be denied all
internal servers and only be able to access the internet gateway to surf the
web and check email.
5. Network Infrastructure The following items are important
pieces to the success of any WLAN implementation. Knowing them and making sure
you have the right infrastructure in place will ensure an optimal wireless
experience for you and your users.
5.1. Switching – New 802.11AC AP’s
have potential for Gigabit speeds. If these AP’s are connected to 10/100 Mbps
switches the potential cannot be realized. We advise and recommend Gigabit
switches preferably with PoE+ for connectivity with the AP’s.
5.2. DHCP & DNS – Static IP
networks can present issues with AP and wireless client functionality. It is
advised and preferred to have a dynamic IP network. Static IP networks can work
but will prove in the end to be an administrative headache. Locally hosted DNS
is also preferred as AP’s will be dependent on name resolution to find their
controllers over layer 3 networks. If your network is a flat layer 2 network
then this is not as critical.
5.3. PoE & Power – Access
points can be powered by PoE (Power over Ethernet) which makes the installation
of cabling to the AP’s very clean and eliminates the need to have AC power
locally at the AP location. Surge protected power will be needed at the
location of the PoE adapters or switches that are providing power to the AP’s.
6. System Management The biggest challenge with a large
scale wireless implementation is trying to manage the users and devices after
the system is installed. The RF environment and user patterns are dynamic, if
you don’t have the ability to manage them from one interface, your operations
costs will go up and your user satisfaction will drop. You need to able to
build the infrastructure once, then be able to grow it, adjust it, and even
provide compliance reporting in some cases. We suggest varying levels of
management based on several criteria and the needs of the organization, but
here is a starting point for you to consider:
6.1. User and Device Management-
you need to be able to assign “Bandwidth Contracts” to users or devices. A
policy might be: each user is assigned 1Mbps of bandwidth from 8am to 5pm but 3
Mbps of bandwidth per user after 5pm.
6.2. Adaptive Radio Management- RF
is dynamic; your system should also be dynamic. You’ll want to see RF coverage
maps in real time so that you know how to trouble shoot any issues. This is a
critical component for those running the user help desk.
6.3. Change Management- in the old
days, you had to configure each access point on your network separately (can
you imagine managing just a 50 AP network?). Today, you can configure one
management console and then push the configuration out to every AP. Likewise,
you should also be able to grow the wireless network simply by installing a new
AP and having it join the WLAN automatically.
6.4. Help Desk/Administrative
Access- there should be an option to set up levels of access for the management
interface. Guest provisioning should be handled by administrative staff or help
desk users. But write access for the major system configuration should come
with high level privileges.
6.5. Reporting and
Compliance-Process logs, device level reporting, trending, network monitoring,
RF health, alerts are all ways to proactively manage your WLAN and your
management system can provide them.
7. Scalability Don’t paint yourself into a corner when
choosing a solution for your WLAN implementation. Make sure that whatever
solution you choose will be able to easily accommodate your future wireless
growth. In our experience as soon as you introduce wireless to your users they
will want it everywhere. When planning take into account a full campus or
wireless everywhere plan even though you may only have the budget for a few
select locations. This will give you an idea of how big you may need to grow
and what solutions can achieve this and accommodate the future scaling.
8. Location-Based Services A location-based service, often
known as Real Time Location Services (RTLS), is the ability to physically
locate a user or device on a wireless network. Think of it as GPS inside a
building. There has been considerable debate about whether a Wi-Fi Network can
handle the capacity of RTLS and if it is accurate enough to locate a device
within a reasonable distance. The answer to the capacity question is that the
right platform can easily handle the load as the data traffic from a
WiFi-enabled RFID tag is very minimal. As for accuracy, the system uses
wireless access points to “triangulate” on a user or device, so the more access
points are deployed, the more accurate the system will be. If considering RTLS,
we recommend defining how accurate you need the system to be, for example:
within 20 ft., then having a wireless consultant (like us) help define how
dense an access point deployment you may need.
9. Redundancy and Reliability Wireless when implemented
correctly will quickly become your user’s main means of connectivity and they
will become reliant on it, HEAVILY. Because of this it will be important to you
and your users that you have ensured High Availability for your WLAN. In order
to achieve High Availability you will need to build in redundancy and other
means of reliability for the system. For many of our customers who are hospital
systems or college campuses, if the system goes down, critical functions are
interrupted (quite literally in the hospital wireless network). Consider the
cost of downtime and how it will impact the organization during the design
process. Then work with an expert to design as much high availability into the
system as necessary. See our sample design for an example of redundancy on the
next page.
10 One of the most critical steps to building a reliable
system is making sure you have the proper level of support to meet your
requirements. Murphy’s Law of critical systems is that something will go wrong
eventually. (For Example: Last year one of our hospital customers had a water
pipe break directly above a data closet housing a critical part of their WLAN
system.) Here are some things to think through to make sure you’re ready:
10.1. Hardware/Software Replacement
Your wireless network will have many different component parts. You need to
understand what happens if something fails or is damaged. · How long is the warranty
on the wireless network components (access points, antennas, software, etc.)? · How quickly can you get
replacement parts? · How
will they be installed when something does go wrong? · How does the system react/adjust
to a component failure? ·
What is involved in adding the replacement to the network?
10.2. Support Being able to get an
experienced engineer on the phone to help handle critical support issues is a
vital asset to maintaining a large scale wireless network. Support specialists
should understand your specific requirements and be able to respond and resolve
issues quickly.
10.3. Maintenance/Managed Services
Your wireless network will have software and firmware that needs to be updated
and maintained on average of once per quarter. We call this a quarterly refresh
of the system to keep it up to date and ensure that the system has the latest
security patches and updates available. This can be a tricky process because
with typically each new release, it brings additional features and potentially,
additional bugs in the software. Consider utilizing an engineer that is an
expert on that particular platform to assist with issues or even provide the
service ongoing to free up your internal resources. Many times utilizing an
expert on a monthly or quarterly basis is more cost effective than figuring
things out internally. Warranty and Support.
11 There is a lot to consider when deploying a large scale
wireless network and mobility Infrastructure. We recommend getting any expert
to help with the successful roll out. Elite Automation Solutions Networks has
many years of experience designing, deploying, and supporting large scale
wireless infrastructure. Here are a few things that make us unique.
11.1. Specialty Focus One-stop
shopping works well in some retail environments. It’s our belief is that it’s
very difficult to achieve in the technology world. In our experience customers
want a technology solutions partner to understand the problem they’re facing
and their industry. Elite Automation Solutions is committed to providing only
the solutions we are experts in, serving the markets we have significant
expertise in. We have even developed industry specific solutions and practices.
We believe this approach creates the most value for our customers.
11.2. We Are Client-Centered not
Product-Centered At Elite Automation Solutions, we take our comprehensive
knowledge and experience to determine which type of solution will be the best
fit for your organization. Many companies who manufacture products do a great
job at marketing their products. The challenge becomes when they recommend it
for everyone even though it’s not the best fit for the customer’s environment. Elite
Automation Solutions has the ability to work on the client’s behalf, cut
through a lot of the marketing jargon, and recommend a solution that is the
best fit for the customer.
11.3. Our Methodology Analyze: We
have industry and solution specific experts armed with software tools to help
understand a customer’s current environment. This is the basis to build any
wireless solution Design: We offer complete solution design services to help
address the challenges. Our design recommendations are based upon your end
goal, as well as industry and solution specific knowledge. Deploy: We deploy
many solutions turnkey or we can work with your team to provide guidance on
deployment best practices and customer specific integration services. Support:
We offer custom fit support services. We offer managed services, unmanaged, or
hybrid support including online portal access and support tools to help you
manage your system.
How Elite Automation Solutions Can
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