Wireless desktop loosing connection while AP hopping

  • 1
  • Question
  • Updated 5 years ago
  • Answered
I have a few wireless desktops that keep loosing connection to the wireless network. In client monitor I see that in the course of the day it will have several sessions, mostly with the same AP, but sometimes with adjacent AP or so. However, when it roams or starts a new session, a number of times it has been noted that the client loses network connection even though it is using static IP addressing.

Authentication mechanism is 802.1x using IAS as the RADIUS server. There is no issue with Authentications though. I suspect that L2 roaming is somehow broken or not working properly as I expect this to be seamless. I have deployed 802.1x enabled wireless networks and mobile clients have roamed seamlessly between AP's.

Couple of notables: 1. The desktop seems to be associating with distant APs rather than the one's closest to it.
2. Although Client wireless card settings are set to be conservative, yet it roams between adjacent AP's, even when one of the APs is clearly closest and strongest to it.

I have adjusted Radio Profiles for high density deployment and reduced the AP power levels to bare minimum. Also, ACSP neighbour in Topology maps seems to show distant APs as neighbour to this AP rather than the one's closer to it.

Appreciate thoughts, guidance, experience on this.

Regards,

Mag
Photo of mag007

mag007

  • 24 Posts
  • 1 Reply Like

Posted 5 years ago

  • 1
Photo of Matthew Norwood

Matthew Norwood

  • 7 Posts
  • 5 Reply Likes
Hi Mag,

I'm curious about a few things.

1. What kind of signal strength are you getting from these wireless desktops when talking to the near and far AP's thay are associating with? Are both bands used, or is it 2.4GHz only?

2. What minimum data rates are you allowing on the wireless side?

3. Are all of your wireless desktops using the same wireless NIC? If so, are they all using the same driver/firmware revision? I am assuming you have other wireless desktops that are operating correctly.

4. Do you get the same result if you place a device(ie laptop) with a different NIC in the same location?

5. Are these wireless desktops all located in the same physical area or are they spread out around the facility and dropping off of different AP's throughout the day?

That is interesting regarding the neighbors that your AP's are seeing. My first instinct was to think it might be a client side issue, but the neighbor piece is making me think you might have a different problem altogether.
Photo of mag007

mag007

  • 24 Posts
  • 1 Reply Like
Hi Mathew,

Here are answers to your questions:

1. In the range of -56dB to -75dB (some even -88dB)
2. 2.4GHz band: 6Mbps; 5GHz band: 18Mbps
3. The one's having problem have all the same Windows image, NIC, drivers, and Wireless NIC settings.
4. No. But at the same time, not all the one' s mentioned in 3 above are having problem despite being in the same area. It is a hospital Ward. Some desktop's are affected more than the others.
5. As above in 4.

We have a high density of APs in this area and high-density radio profile is configured. This is for location tracking and running voice (not being used yet).

Thanks
Photo of Matthew Norwood

Matthew Norwood

  • 7 Posts
  • 5 Reply Likes
Sorry for the delayed response. Work got in the way. :)

If I understand correctly, the common element is that the problematic systems are all the same from a hardware/driver perspective. However, not all machines are experiencing the problem.

If there isn't an obvious physical location difference with the client machines, as in the problematic ones are further away from the closest AP than the ones that are fine, I am at a loss. When dealing with any sort of sticky client issue, there is usually some commonality with those that work and those that don't. For example, we had a problem with Windows 8 machines at the office connecting to Cisco 1142 AP's. We replaced our Cisco AP's with Aruba AP's and the problem went away.

This is especially odd considering these are workstations that I assume never move location.

If we rule out AP load, then I honestly have no clue what could be causing certain workstations to stay connected to far AP's. Your RSSI values look good. Are the problematic machines using 2.4 and 5, or just associating with 2.4? What about the machines that are working? Using both bands, or just 1? If 1, which one?