Customer clients Frequently get disconnected from Netvanta 160's

[cpetech]

I have a customer with 2 Netvanta 160's running off a 1234p Switch, R11.2.0HB.  This is a very wireless saturated office building, over 20 other access points from other business's.  What i tried to set up was was two SSID's one for the business owner and one for his guests on each access point so they could move about the building and still have access to whatever 160 had the strongest signal.  He is complaining that some of his workers are frequently getting disconnected.  The signal bars diminish until they disappear then reconnect or the folks have to reconnected themselves.

I have attached some screen shots from inSIDDer and Vistumbler.  On Vistumbler I see 1 MCFS Guest radio, and 2 MCFS radios.  Radio number 3 E8:01 can go from 85% signal to 0% dead signal, the other two stay pretty strong.  Not sure why i have 2 of one show up and only 1 of the other.

My background is in Mitel and Avaya phone systems so the wireless switches and WAPS are new to me.  I have attached the 1234p switch configuration if that helps.  I'm sure i have programmed things wrong just not sure what.

Any help would be greatly appreciated.  Thanks

[Anonymous]

The first thing I note on your INSSIDER shot is that you are on the 2.4 GHz band and it is pretty crowded.  Further you have two of your own on channel 11.  You have 3 non-overlapping channels, 1, 6, and 11, in the 2.4 GHz band  I would move one that is on channel 11 to channel 1.  With this change, you will have reduced in channel interference from within your facility and this will help a lot.  However, I also note that your SSIDS are being interfered by others that are of about equal strength.  This overlapping channels with nearly the same intensity causes a lot of problems.

I suggest you go to the Meta Geeks web site and get a bit more familiar with overlapping channel interference and related matters; they do a nice job describing what is going on.

If you can go to the 5.0 GHz band you may find things a lot cleaner.

Additionally, there may well be interference from a non-802.11 2.4 GHz source causing the disconnects.  You may sidestep this by going to 5.0 GHz as well.  However, I did exactly that in an install in January and we still have some disconnect issues.  We have seen, with the aid of a spectrum analyzer, intense and intermittent interference in the 2.4 GHz band that forced the NV 160 to reboot.  We were using both the 2.4 and 5.0 bands at that time. 

We disabled the 2.4 GHz entirely and updated firmware on the NV160 and the Netvanta 1531P to firmware issued in very late April.  This has helped but it has not ended the problem by any means.

As of today, we note that sometimes the AP reboots, presumably due to intermittent interference (even in the 5 GHz band), the reboot is not clean.  Specifically people cannot connect to the AP yet INSSIDER shows the AP channel is on, the SSID is broadcast, there is a ping response to the AP's IP address, and the Access Controller (NV 1531P in our case) shows all is normal.  A reboot resolved this but it had to be done on site (I do not know if there is a way to remotely reboot the NV160 as this would have been helpful).

I hope this has been helpful to you

[cpetech]

gtb,

Thanks i will look into the Meta Geeks site for a better understanding of wireless issues.  I did just turn on the 5.0 radio for these folks, and cleaned up some other programming.  It's dissapointing to know that with all that you have done for your cusotmer you are still getting some disconnect issues.

Thanks for your reply, much appreciated.

[Anonymous · Accepted solution]

To add to what Gene is saying,

In most cases, these issues are absolutely related to RF interference around the APs. RF interference causes poor client connections, disconnects, speed issues, etc.

I would start by going through Troubleshooting Interference on a NetVanta 160 Series Access Point‌ first as it contains many helpful remedies for this and walks you through them.

If you still have these issues and have an in-warranty NetVanta 160 or a support contract, you should contact ADTRAN Technical Support.

Thanks,

Evan

[Anonymous]

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Thanks,

Noor