Wireless Best Practices - 12 Sep 2007

Chances are, you've got a wireless network that you're not entirely in control of. Or perhaps you've carefully deployed wireless in your environment, and you've mistakenly believed that you could just set it and forget it. You can do that with many computing technologies, but beware doing it with wireless! I spoke recently with Charles Thompson, manager of sales engineering at Network Instruments, and he gave me some best practices to share with you. I offer these tips along with his elucidation of each.

Best Practice #1: Conduct a Wireless Site Survey
The more you know about your network, the better prepared you are to properly integrate wireless. It’s important to conduct a wireless site survey to understand how the WLAN will perform and how access points (APs) should be positioned. Wireless site surveys can also indicate neighboring traffic that may interfere, environmental issues, and other potential obstacles.

Charles adds, "Obviously, we're talking about the predeployment phase of a wireless deployment. The environment can have a huge impact on the quality of service you provide. You have to ask yourself, What does the environment look like? What about the construction of the building (metal shielding can cause wireless frequencies to have some odd properties)? I've worked with a number of sites that do site surveys and a number that don't. At first, most companies didn't perform this important first step, but now it's becoming more common."

Best Practice #2: Implement a Strong Security System
A strong security system needs to be in place to prevent everyone from gaining access to your network as well as protect against any vulnerabilities of the wireless network. Unsecured wireless networks can often be the target of people looking for free wireless access or hackers looking for a place to launch an attack.

Charles adds, "I always look at wireless security from two perspectives: access control and data security. Of course, you should always ensure that only authorized users are consuming your available resources. But also, often, businesses are liable for the traffic on their networks. Is it coming from approved sources? With wireless, data can be picked out of the air. Eavesdropping is simple! Be sure to encrypt your wireless data, sure, but also focus your wireless access. Don't expand your coverage too much. Adjust the power output of your AP."

Best Practice #3: Plan for Future Growth
Administrators need to plan for future growth. They may only have 20 users today, but demand can grow quickly with 200 users wanting wireless access tomorrow. It’s important to install an architecture that can grow with the needs of the organization to avoid costly redesigns.

Charles says, "Many wireless network aren't properly planned. If you do properly deploy wireless technologies into cells, you can create a very high-capacity environment. Match up your hardware and technologies. Orchestrate coexisting traffic along different protocols. Different wireless protocols can coexist without interfering with one another."

Best Practice #4: Deploy Analysis Tools Strategically for Maximum Visibility
Placing network-analysis consoles and probes on your wireless network requires a clear understanding of wireless traffic patterns. Are you concerned about monitoring local or remote wireless traffic? Proper placement of your analysis tools is key to ensuring optimal visibility of your local and remote networks as well as meeting your overall monitoring objectives.

Charles adds, "In the RF space, let's say you have to be 100 feet away from something, at a given power level, to communicate with it. Well, at the same power level, you can be 200 feet away from it and merely listen to what it's transmitting. Try using directional antennas to get coverage and a great, big, powerful ear for monitoring. Be smart about how you deploy."

Best Practice #5: Monitor WLAN Rollouts to Ensure a Positive User Experience
Determine whether the users' experience is positive or negative by reviewing cumulative wireless metrics and other network-performance variables during deployment. By evaluating WLAN setups and overall link utilization, you can judge overall network performance and quickly make necessary adjustments during implementation. By continually monitoring wireless network performance and establishing benchmarks, you can define acceptable wireless network performance and know quickly when the wireless network falls below acceptable levels.

Charles says, "Use monitoring tools during your deployment to ensure a strong implementation. You can't just deploy wireless and walk away from it. Lots of things are going to affect the experience. It's a constantly changing dynamic. About four months ago, I was at a site that had a wireless connection between two buildings on a campus, with antennas mounted on the side of the building. The users were happy when it was installed, but gradually the connection became sporadic, then worse and worse. Finally, they did a line-of-sight survey. What had happened was a tree had grown up between the two points, blocking the connection. That's a blatant example of ignoring routine maintenance, but it reinforces the fact that you have to stay on top of the environment."

Keep these tips in mind if you're considering or even experiencing wireless in your environment, and do take a look at Network Instruments' Observer platform (now on version 12.1), which lets you look at your wireless network right next to your wired network. That kind of coexistence is important to a healthy wireless environment.

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