Wireless Speeds Flucuating

[Daniel Brown]

We have approximately 150 1142 LWAPP's deployed in our facility. Recently we started getting complaints about speed issues (90% are using G 10% N). Upon investigating we found that the speeds are flucuating rapidly. Everything from 54Mbps down to 1Mbps and back up again. I've confirmed that this will happen while standing next to an AP (and confirming connectivity to it), however I cannot find anything wrong or anything that has changed with our configuration. We are a large facility and it is happening all over the campus, so I'm fairly certain it isn't any type of 'normal' interferance.

I'm at a loss and not sure where to keep looking. If anyone has any tips I would greatly appreciate it!

[Leo Laohoo]

90% are using G

Did you disable the 802.11b data rates?

No one using 802.11a?

[Daniel Brown]

The A radios are on as the ultimate goal is to move everyone to N. However, even on N the problems seem to occur. Data Rates for 2.4 are -

1

2

5.5

6

9

11

12

18

24

36

48

54

All of which are in Supported mode other than 1,2,5.5 and 11 which are set to Mandatory. If I disable them what would the impact be? Will clients not be able to connect?

[Leo Laohoo]

If you disable the 802.11b data rates, the circumference of the "footprint" of the 802.11b/g signal.  This will also ensure that clients closer will be "forced" to jump to a higher rate.

[Daniel Brown]

I'm willing to disable the speeds (will probably wait until Monday, though) however the clients are connecting at 54mbps (usually) and then bouncing back and forth after a connection is made. My understanding of the speed settings were that a client could connect at those speeds. If I disable those how will it force clients who have connected at a different speed to stay at that particular speed setting.

[Daniel Brown]

I've been doing some data collection today. Although I cannot recreate the issue (go figure) perhaps this graph from inSSIDer will give some details?

[Leo Laohoo]

Wow.  > -80 dBi.  That's pretty bad signal.

Good thing about the application is it'll tell you what's going on around you.  Bad thing about application like this is without a floor plan with the location of all your WAPs, it's very, very difficult to interpret the data.

My recommendation is get a floor plan, mark all the WAPs' location on the floor plan and go to a particular location.

From there, "chart" the following information:

1.  WAP channel in both radios; and

2.  WAP signal strenth (RSSI) in both radios.

[Daniel Brown]

Thanks for the reply. Unfortunately that was standing right next to an AP. I'll need to do like you said and map the MAC to an AP and see what is reading from where.

Also, I learned today that I cannot disable the B rates as we have 200 propretairy devices that are B only. They are separated onto a different SSID.