Question

If you search on the Web for the major issues of wireless networks, you'll find numerous articles and documents that identify 3 or more (mostly more) issues or challenges of wireless networks. Do this research and list what you believe to be the 5 most important or problematic issues facing the design, implementation, or operations of a wireless network.

Answer 1

The 5 most important issues of a wireless network:

1. Design Issue

The reliability of your WLAN is heavily dependent on not only the architecture of your hardware and software but also the design and placement of the crucial pieces of your network. So if you’re getting spotty signal in certain parts of your WLAN, make sure that your access points and routers are positioned optimally.

Walls, ceilings, and other large objects can inhibit the reach of your wireless signal. Even things like metal filing cabinets can affect your WLAN’s performance. Therefore, moving your hardware to the right place can be just as important as sourcing the right hardware.

Physical object interference is one of the most common issues that can be diagnosed with the naked eye, but another type of interference which is invisible is a huge PITA to IT pros that we work with: RF interference.

2. RF Interference Issue

802.11 technology has made the overall performance and reliability of WLAN networks much more suitable for daily enterprise use. Despite this, an invisible culprit often puts a fork in the road regarding signal strength: radio frequency (RF) interference.

RF interference can be caused by any device that emits electromagnetic signals. Examples of devices that emit these signals are:

• Mobile phones
• AM/FM radios
• Televisions
• Microwave ovens
• MRI machines
• Wi-Fi routers

The previously mentioned devices can be seen in almost any enterprise organization or large WLAN networks. Due to the underlying technology, even 802.11n access points themselves can be a source of RF interference.

Fortunately, many access points and network management tools like Cisco PRIME allow IT admins to identify the sources of interference. Despite this, identification doesn’t help solve the problem. Later in this article, we will discuss potential ways where we have helped our clients solve their WLAN issues due to RF interference.

3.  Incorrect Antenna Configuration

If your WLAN router has antennas, the positioning of them can make a huge difference when it comes to the strength and reliability of your wireless signal within your network. Some wireless AP manufacturers will suggest a preferred way to position your antennas, but we typically have encountered the following types of configurations during wireless audits:

• Upright – all antennas are pointed upright, perpendicular to the router
• 45 degrees – all antennas are angled at 45 degrees to the router
• Flat – all antennas are positioned on the same plane as the router (0 degrees)
• Perpendicular – antenna position is mixed, with some upright and some flat, overall making the antennas perpendicular to each other

On 2.4GHz networks, we’ve seen the perpendicular antenna configuration to be the most optimal. On 5GHz channels, we’ve seen that anything but the flat configuration seems to perform well.

There are exceptions to our experiences, however. The point is that your WLAN antenna configuration is just one potential way to tweak your network hardware to increase the signal strength and reliability of a particular part of your WLAN.

4.  Hardware Architecture & Firmware

Hardware issues are another major contributing factor to poor WiFi performance on large WLANs. More specifically, the two most common hardware issues we see affecting WLAN performance are either having not enough or too many access points, or having outdated firmware.

Deciding on the number of access points your network needs can be tricky. This design issue can be challenging for even the most seasoned WLAN architects. Also, power configuration and channel selection can make the architectural decision-making process more complex. There is no straightforward answer to this issue and the type, number, and configuration of your WLAN’s routers, controllers, and access points will depend on your network. From a business perspective, choosing the right mix can also contribute to budgetary issues which can affect the bottom line. Overall, doing your due diligence and investing the appropriate amount of time into the architecture of your WLAN’s hardware is a crucial step that should not be overlooked.

In addition to power configuration and channel selection, firmware updates can have a major effect on your WLAN performance. Security updates and bug fixes are addressed in firmware updates, and sometimes a coordinate update plan is all that is needed to fix wireless signal and performance issues.

5. WLAN Security & Protection From Internal/External Threats

Sometimes, firmware updates can address security issues. However, many security issues need more than just a hardware update to fix, especially when it comes to protecting your network’s integrity and sensitive data.

Common wireless issues that we’ve seen include, but are not limited to:

• Rogue APs or ad-hoc networks – Setting up a rogue AP in the proximity of an existing WLAN with the attempt to fool devices into accessing this AP instead of the correct one.
• Denial of service – Network attack where large amounts of traffic at a specific target, or through purposely interfering with a WLAN networks connectivity (e.g. through RF interference)
• Configuration problems – Usually an internal issue with hardware/software is not configured with the proper security protocols
• Passive capturing – When an attacker gets within range of a WLAN and attempts to ‘listen’ or capture user data of people on that network

On large enterprise networks where there is a mixture of both public and private networks with a variety of different user types, security configuration can be a very complex task. Despite this, it is a necessary task that needs to be planned and executed well.

At a minimum, we recommend WPA2 as the preferred type of wireless security protocol for authentication. WPA2 is relatively more secure that its counterpart options. For large networks and enterprises, external firewalls, endpoint protection, anti-virus, and malware protection, and even network access control solutions like Cisco ISE should be a standard in WLAN architecture and design.