WAP125 Poor performance

[Rog28837]

I recently purchased a WAP125, everything works fine in 802.11b/g mode 2.4Ghz only. But when I switch to b/g/n or just n mode its initially much faster, close to the speed of my ADSL link in a download test, but then it suddenly tanks and drops from 50(ish) to 3 and then eventually <1. A speed test performed on a wired connection still shows a decent speed 55(ish). This seems to have been a problem on the WAP121 (Solved: WAP121 extremely slow - Cisco Community) which is where I got advice to revert to the older standards but that was 'solved' without actually fixing the underlying issue just tolerating it.

[Scott Fella]

Always make sure your device has updated drivers.  2.4Ghz isn't really the best to use these day's.  Typically you would disable lower data rates or at least disable 802.11b data rates so devices don't use those.  Then you also need to look at what your device is connecting to and what its connecting to when you have issues.  Also a drop in throughput on 2.4Ghz can be due to interference like microwave or high utilization from surrounding wireless also on 2.4Ghz.  Also, always test with multiple devices to verify if one works better than another to help eliminate variables.

[Rog28837]

Hi Scott, the device came preinstalled with the latest driver 1.0.3.1. The distance, and walls, between router and the furthest point in my house make 2.4 seem the better choice for at least some connections but I initially started with everything turned on which means 802.11ac/n on this device. I've only started to reduce the standard because of the this issue and as per the other WAP121 thread it does 'fix' the problem in a way.

Looking at a WiFi scanner nothing stands out as a problem, certainly nothing different between a solid b/g connection and a problematic n one (I had no issues at all with my previous WiFi router, for the same client devices). I've been able to repeat the problem 8 or 9 times now at various times of day using the same clients to connect (a laptop & a phone coming in through different SSID's on the same WAP). It's always the same pattern, I change the band to allow a faster connection, it takes a moment for the clients to reconnect and its fine at first but then drops rapidly and within a few speed tests its unusable. Once the problem has occurred I can be stood 6 feet away from the WAP and it'll only get <1 on a download test.

[Scott Fella]

I meant the driver of the wireless device like your laptop. Wireless access points should be fine with g, a, n, ac, ax enabled and b disabled. When you have slow performance, connect or check with another device and see if it’s slow also. That can help eliminate a device or possibly the access point. I have a bunch of tool I use, but WiFi explorer pro is a good tool to also look at overlap channels and utilization. If everything seems normal and speed just drops, then it’s probably your ap. Maybe downgrade the ap to do more testing.

[Rog28837]

All the devices are upto date, all work perfectly with a different AP on the same network, there are no channel overlaps. The mosdt annoying thing is that all the devices all work really well in the first 20 mins after I've switched the standard back to n or b/g/n they just don't maintain that performance.

[Scott Fella · Accepted solution]

Well the only thing left to do is factory reset that ap an build it from scratch. That ap is 802.11ac so it should have 5ghz. Why are you just testing 2.4ghz?

[Rog28837]

Hi Scott, I initially did a software factory reset and it was still flaky but then I tried the hardware reset button and all is well. I've not risked reloading my saved config but all the bits I care about and there and the performance has been great for the last hour or more which is 3 times longer than previously so I think that's cracked it. Many thanks for your help.

[Martin Aleksandrov]

Hello Rog,

if after the factory reset you face the same 802.11n performance issue you then have to contact the Cisco technical support centre to further troubleshoot the device. There is a likelihood of the 2.4GHz radio failure on the WAP. Tech support contacts are as follows:

https://www.cisco.com/c/en/us/support/web/tsd-cisco-small-business-support-center-contacts.html 

Regards,

Martin