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WiFi Problems - Range, Channels and non-broadcasting AP's

Posted: Fri Jun 08, 2012 12:31 pm
by pingsteve
Hi All,

In our stake we have 4 buildings. Each building has the Cisco 881w and either 2 or 3 1041N access points depending on building design and layout.

In the past week, I have heard complaints of poor WiFi coverage from three of the four buildings and haven't yet had a chance to check the fourth. Here is what I have discovered:
  • At least one 1041N is not broadcasting in two of the buildings. I do not see the "dead node" with a WiFi analysis app on my tablet, even if I'm standing right next to the AP
  • Channel 1 seems to be the most popular channel. I usually see 2 and sometimes 3 APs broadcasting on this channel
I'm looking for guidance here.

How do I get the APs to start broadcasting again? This setup has been working for about 9 months, but just stopped working recently.

Also, how do I get the APs to choose a different channel? I don't see anything in the higher channel range, but I see our APs and a number of neighboring networks on Channel 1

Thanks,

Steve in Meridian ID

Posted: Fri Jun 08, 2012 12:37 pm
by aebrown
This is a job for the Global Service Center. Clearly it's not good to have all devices using channel 1, but only the GSC can control the scripting of the 881w and the 1041n devices. So call the GSC while you're in the building and let them work through the issues with you.

Posted: Fri Jun 08, 2012 1:33 pm
by russellhltn
I'll second Alan's advice. But I'd also point out that you may need to do some basic troubleshooting of the one "dead" AP. Is it dead or just not broadcasting? Is it getting power? Is the network connection back to the firewall ok? Does it have a status light? GSC can work with it only if it's connected and powered up.

Posted: Fri Jun 08, 2012 2:39 pm
by pingsteve
aebrown wrote:This is a job for the Global Service Center. Clearly it's not good to have all devices using channel 1, but only the GSC can control the scripting of the 881w and the 1041n devices. So call the GSC while you're in the building and let them work through the issues with you.


Thanks for the advice. I've never called the GSC before, are they usually available after business hours? I'd rather not have to take time off work to troubleshoot this.

Posted: Fri Jun 08, 2012 2:40 pm
by pingsteve
RussellHltn wrote:I'll second Alan's advice. But I'd also point out that you may need to do some basic troubleshooting of the one "dead" AP. Is it dead or just not broadcasting? Is it getting power? Is the network connection back to the firewall ok? Does it have a status light? GSC can work with it only if it's connected and powered up.

The "dead" AP does have a light but it is not broadcasting.

Posted: Fri Jun 08, 2012 2:45 pm
by aebrown
pingsteve wrote:Thanks for the advice. I've never called the GSC before, are they usually available after business hours? I'd rather not have to take time off work to troubleshoot this.
Yes, the GSC is available after business hours. If your problem has to be escalated, the right people might not be available after hours, but for almost everything I've ever done with the GSC, the first-tier support people do just fine. They're not available Sundays until the afternoon, but otherwise they're basically available 24x6 (it's a Global service center, so they have to support all time zones).

Posted: Fri Jun 08, 2012 2:52 pm
by aebrown
pingsteve wrote:The "dead" AP does have a light but it is not broadcasting.
You could simply try power cycling the 1041n. I assume it's using PoE, so you'd just have to disconnect either end of the Ethernet cable between the 881w and the 1041n, wait a minute or so, and connect it again. You might also check the cabling. If it is powered by a power injector, it's possible that the cable from the 881w to the injector is bad or poorly connected, but the cable from the injector to the 1041n is good. That would give you power to the 1041n, but not data. It also might help to power cycle the 881w.

Posted: Fri Jun 08, 2012 3:00 pm
by johnshaw
If you haven't already, you might simply power off the WAP wait 30 sec or so and power it back on... take note of the indicator lights to see what the issue might be. If it comes back up Green, it should be ready to go, connect a device and watch it turn blue... if that doesn't happen, find the instructions to 'reset' the device. If you call the GSC they will likely want to do this anyway. You might call them during the day (while their knowledgeable people are in - I might suggest Tim Johnson) and get some troubleshooting steps you can perform off hours as well.

I've been told that the automatic config of the 1041n/881W will boot and determine the best channel to use. If it senses another WAP or signal on a channel in too close proximity it will choose another channel than what it has discovered, but otherwise it will just use 1... If that isn't true, it was a line I was fed by the GSC rather than make the change to my WAP's that I wanted (separating them on different channels)

Posted: Fri Jun 08, 2012 3:25 pm
by russellhltn
JohnShaw wrote:I've been told that the automatic config of the 1041n/881W will boot and determine the best channel to use. If it senses another WAP or signal on a channel in too close proximity it will choose another channel than what it has discovered, but otherwise it will just use 1.
It may do that, but it seems to me that it's entirely possible that because of location differences, the user can be affected by things the WAP can't hear. I could be wrong, but I don't think having two WAPs on CH 1 is going to work well for someone halfway in between.

Posted: Fri Jun 08, 2012 3:26 pm
by pingsteve
aebrown wrote:You could simply try power cycling the 1041n. I assume it's using PoE, so you'd just have to disconnect either end of the Ethernet cable between the 881w and the 1041n, wait a minute or so, and connect it again. You might also check the cabling. If it is powered by a power injector, it's possible that the cable from the 881w to the injector is bad or poorly connected, but the cable from the injector to the 1041n is good. That would give you power to the 1041n, but not data. It also might help to power cycle the 881w.

I have power cycled both the 1041 and the 881, but no luck. I did observe the WAP cycling through the colors (red, green yellow?), but I don't believe it ever came up to a solid blue (as suggested by JohnShaw). It may have been flashing blue, I'll have to pay closer attention next time.

I know for a fact that it did not turn green. I wonder if it would be worthwhile to turn off the other APs and see if just this one will come up.