Wireless Access

Quick question,

 

Is the "Advertise 802.11d and 802.11h Capabilities" option a requirement for DFS to work? 

Or is setting the regulatory domain correctly enough to abide by the DFS laws? Is DFS active without those 11d and 11h capabilities?

 

Is there an easy command to see DFS 'states'? Whether an setup is adhering to the DFS requirements and whether it has seen radar on any channels recently?

802.11d is required by 802.11h which is required for DFS. :) Did I confuse you? I always enable both.

 

I don't know of a "compliance" type check, but I think that would make an awesome feature request.

 

If you have visiting guests using WiFi cards not manufactured for your country, advertising the 11h beacons may allow them to use the correct DFS channels for your country.  They won't use any illegal DFS channels because your APs don't, but they may have trouble with specific APs if the 11h info is not advertised.

 

We run with it on, but we currently have not yet turned on channel change notifications -- among the standards waiting in the wings for old clients to age out, the channel change notifications are probably the very next thing we will try to turn on, then 11k.

 

You can view which channels your APs are on with a "show ap active" on the controllers.

 

To see Radar events, grep the controller syslogs for "Radar".

 

As to whether your setup is adhering to DFS requirements, it's on the vendor to provide proof of that during device certification; you just need to select the right country and make sure all outdoor APs are provisioned as outdoor, unless there are additional local restrictions due to your location.

 

EDIT: slipped my mind cause I don't use them: also tell the system the correct gains of any external antennas.

 

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@bjulin wrote:

 

If you have visiting guests using WiFi cards not manufactured for your country, advertising the 11h beacons may allow them to use the correct DFS channels for your country.  They won't use any illegal DFS channels because your APs don't, but they may have trouble with specific APs if the 11h info is not advertised.

 

 

As to whether your setup is adhering to DFS requirements, it's on the vendor to provide proof of that during device certification; you just need to select the right country and make sure all outdoor APs are provisioned as outdoor, unless there are additional local restrictions due to your location.

 

EDIT: slipped my mind cause I don't use them: also tell the system the correct gains of any external antennas.

 

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see, that is what I thought.. just select the correct country and provision your AP's correctly and you're done. 

 

According http://en.wikipedia.org/wiki/IEEE_802.11h-2003 802.11h is required for DFS on the APs. Yea Wiki, i know, not always too reliable.

 

So can some Aruba folk enlighten me?  Do I need to manualy enable 802.11h (default = disabled) to adhere to ETSI standards?

Is that trigger making the APs do DFS/TPC and the likes or is that trigger just there to communicate to the clients what the AP's can do?

 

I also thought that DFS would always disable a DFS channel when it detects radar (or other) traffic on it.

Last, however, a customer got a complaint that he should disable channel 124, because it was causing interference on some police radio. The wlan installation is an Instant cluster.

 

 

I've removed the channel from the allowed channels on the Instant cluster. Would this be the way to go?

Would  enabling 11h make a difference?

What should we do to avoid such issues to begin with?

 

Br

Peter

You should ask the locality what is allowed and what is not allowed, and disable those channels. The DFS mechanism looks for specific signatures to pass testing, but it does not account for all transmissions.

Thx Colin

 

So the regulatory domain is not always valid for the whole country?

And 11d, 11h is not having an effect on the AP and it's DFS channels (DFS works without) but it can have an effect on the clients?

 

Peter

The regulatory domain should be valid for the whole country. With DFS channels when a government agency asks you to stop using it, you need to stop, period. I am not aware of the circumstances of your customer, but those are the terms of using those channels in the first place.