Hi All,
I got called out to school yesterday who have been experiencing some issues with their wireless slowing down when allot of devices are connected. The school has 12 IAP 93's, 8 in their main building and 4 in a new building. The WiFi was installed about 18 months ago but back then they only had 10-15 laptops for the students. They have recently purchased another 100 or so laptops for the students and are now experiencing problems.
I logged in to the virtual controller and it was showing that 25 devices were connected to 1 AP while the 4 surrounding AP's only had 2-3 devices connected which is obviously not ideal. I started by upgrading to the latest version of code to see if it was a bug in the ARM as they hadn't upgraded them since they were installed. This didn't resolve the Issue so I rebooted the AP all of the devices were connected to to try and force them on to other AP's within range, which they did but they all started to flag as poor signal as soon as they did. When the AP came back online they all started to re-associate with that AP. I left them running for a bit and then went through the clients association history and I could see some of them were jumping between different AP's but they always ended up reconnecting to the first one. It seems like ARM is pointing all of the clients towards this one AP as it is the only one with viable signal but would it continue to do this even if the AP is struggling?
I checked the AP stats on the virtual controller and the CPU & memory for the AP looked ok so it didn't appear to be struggling that way, the AP also showed 5 neighboring valid AP's which ties in with the physical locations onsite and reasonably close by so I would expect them to be able to hand off to each other.
While on site I did notice two things that could be contributing to the issues. Firstly the AP's are not mounted on the ceiling, they are mounted on the walls and all of the surrounding AP's are mounted with what should be the bottom of the AP (hopefully that makes sense) facing away from the area with the issues. Also because the school has no POE on their switches the AP's are going in to a number of 4 port POE hubs (3 AP's in each hub) and then the hub is connected to the schools network, the problem is the hub is only a 100Mb and the schools switches are gig so I'm thinking instant bottleneck. If we could eliminate the 100Mb and have all of the AP's connected to the network on a gig link could they handle 25 devices or would it still struggle?
Basically what I'm asking is.
1. Will Arm keep associating clients to an AP even if its struggling if the other surrounding AP's don't have the signal strength to support them in order to keep them all connected?
2. How many devices will a IAP93 comfortably support before it starts to struggle? I've seen some test doc's where 60 devices have been hooked up to a AP135 without any major problems but obviously the AP93 & 135 are two very different bits of kit.
If it’s a case of relocating the existing AP's to be ceiling mounted, swapping the AP's to dual band units or simply installing more AP's then that’s fine but I don't want to suggest a course of action that isn't going to fix the issues they are having.
Any thought's suggestions would be greatly appreciated.
#AP135