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How do I diagnose a slow WLAN guest network?


I have Laura's newest Wireshark Analysis book (2010, anyway) and have been reading through it to try and solve a problem.

Our guest WLAN is slow at times. Each user is capped via the wireless distribution system at 1mb/s download, and capped uploading and downloading at the DMZ to 8mb/s, but that is the entire pipe, not per user.

I have eliminated the RF side of the house, which is what I thought it was. Not congested or experiencing interference. We put a copper port in the same network (also eliminating the WLAN) and we still experience the problem.

Put Wireshark on my laptop and associated to guest WLAN. Every now and then when I browse the Internet, it gets super slow and pages timeout.

I would like to snag a capture of when the network is slow and go from there. I was thinking this was the best angle since I want to see what's happening from the user's experience.

Can anyone give me some things to look for? I suspect there are too many users trying to use the guest network's 8mb/s pipe. All I have to do is prove it.

asked 27 Sep '11, 12:20

tdennehy's gravatar image

accept rate: 0%

One Answer:


From what you've written I conclude two main facts:

  1. You said that even using a copper port you experience the problem
  2. You already know that there is a throttle in your Wireless distribution system

So a good way to go from my perspective would be to take a trace at the uplinks of the wireless distribution system connecting your guest WLANs and look at the traffic there. Maybe you can even just recover something from the logs if your controller is capable and configured to monitor bandwidth usage.

Sniffing from a wireless client you can only tell that there IS a problem, but not if thats connected to too many users on the guest network.

answered 29 Sep '11, 01:44

Landi's gravatar image

accept rate: 28%

edited 29 Sep '11, 01:45