Take the 2-minute tour ×
Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

We have a small office with a large number of wireless devices (a mixture of desktop machines, laptops, and wifi-enabled phones) all working from a single Apple Airport Extreme which extends our wired network. I've added another Airport Extreme for resiliency, since we've been seeing a decrease in performance and (as far as I understand) access points can only handle a small number of clients.

I set the new AP to extend the current network so that the clients weren't constantly switching between different wireless networks, however as soon as this AP was configured all the wireless devices started seeing network trouble, flicking on and off.

I'm assuming that this is because both APs are reasonably strong, and the client can't decide which to use.

What is the best route to follow to resolve this? What I'm aiming for is wireless resiliency; preferably having two APs share the network load, or if this isn't an option then having a primary AP with a "fail-over", should the primary go down for any reason.

share|improve this question

3 Answers 3

I think the first step is to verify that your clients are indeed switching between the 2 APs. You can probably check this by looking at the BSSID for your connection before you drop and seeing what BSSID you get when you reconnect. If that is definitely the problem, then you need to decrease the size of each AP's cell by lowering the output power. If you can decrease the size of each cell, each client will get more bandwidth from the AP to which it's connected.

You should make sure that the APs are on different channels too. If the APs are on the same channel, you will see some co-channel interference degrading your performance. The only other problem I can think of here is you might have hidden node issues. Turning on RTS/CTS will fix that problem (you may need to lower your threshold if you can't manually turn on RTS/CTS).

share|improve this answer
    
Make sure the "different channels" are non-overlapping as well. The Wikipedia page at en.wikipedia.org/wiki/… has a good illustration of channel overlap. 1, 6, and 11 are the de facto standard (in North America, at least). –  Gerald Combs May 6 '10 at 19:40

If you have such a strong area of cross over for the access points, would you not be able to either just use the one or move them as far apart as your building allows?

share|improve this answer
    
They're already at opposite ends of the office, but thanks for the suggestion. –  Phillip Oldham Apr 16 '10 at 9:26

alternatively, lower the power output of one of them depending on physical location in the building to keep the overlay to a minimum

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.