Need assistance from an Aruba Guru

M

Mackintire

2[H]4U
Joined
Jun 28, 2004
Messages
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I 'm trying to get our clients to migrate from AP to AP or even every other AP.

Our APs are 40' from each other in a high noise environment with 2-3 interfering APs seen by each of our APs.

Our controller was updated to software version 5 and I did some basic tuning, such as removing the lower data rates and min power output...although in this version the measurement of units is EIRD or something to that effect. I have it set to 15.

For the RF optomisation handoff profile:
What RSSI value should I be targeting for forcing the clients to switch APs? I would prefer they switch if the client sees less than -75db.



We're currently using AP65s which are ancient, we're moving in 2 months and will be swapping them out for AP 105s and AP134s at that point.
 
Are you trying to get the clients to migrate gracefully? Using the handoff assist is going to send a deauth to the client and force them to reconnect, very 'ugly' solution imo and not the best for client expectations.

What version of arubaos is the controller on? You need to be on at least 5.0.3 to use the local probe response threshold. That is your best option for resolving sticky clients. Anything else is going to cause disruptions. Start with a low setting like 12db and go up from there until the problem is mitigated. You can never really solve sticky clients, just make it better.

I would also re-add the lower data rates, as a lot of older clients won't connect if those are disabled.

Another thing, jacking up the minimum power output so high is just adding more interference in to your environment. If the AP's are that close, you need to change your ARM profile settings for ideal and minimum coverage index. Start dropping them little by little, drop it and wait a day or so, see if it makes a difference, keep going but do not make fast changes. Let the controller decide the power output. If you are going in and changing power and channel settings you are defeating the whole point of having a controller that can change that stuff on the fly.

One last thing, with wireless.....DOCUMENT EVERY CHANGE!!! Otherwise you will fix an issue and have no idea what you did to fix it.

As I like to tell everyone about wireless.....I can give you five reasons it isn't working, but I can never give you just one.


*edit* Oh yeah, the local response threshold setting is in the SSID profile as its a per SSID setting. Sorry
 
We're running 5.0.3.3

I 'll look into the local probe response threshold option.

"I would also re-add the lower data rates, as a lot of older clients won't connect if those are disabled." Yes we are trying to make sure all wireless b clients can not connect. That and if you can not connect at the rate defined the client will disconnect and reconnect to a closer AP ;)

Now that I am at work and can see the interface....(2) of my APs are hitting the minimum EIRP I set previously off and on, so I think the power output is close to where we might want it.
Do you have any guidance on the adjusting the Ideal coverage Index? or the Acceptable Coverage Index?
 
The local probe repsonse is basically just telling the AP's, that if a client probes them, and the snr is below a certain value, don't respond.

Coverage index is a metric that looks at snr of neighboring AP's, interference, etc, and also neighboring ap's values of that particular AP. The higher the index number, the higher it will want those snr's to be. Usually in a dense deployment you want that set lower, as that will keep interference down as you don't have AP's battling each other in the same space on the same channel, but in some cases like when you put the AP's in hallways, the AP's have great SNR to each other, even though they are far apart, and you don't necessarily want them to turn down because then the coverage in the rooms adjacent to the hallway will suck. So you either put the index value higher, causing the AP's to keep the power up even though they can see the other AP's very clearly, or you adjust the minimum tx power, or you set both.

Ideal is the ideal coverage index that the radio will try to reach, either by changing power output, changing channel, etc.

The acceptable coverage index applies to single radio models when you are using dual bands, and also single and dual radios when you are using the mode-aware arm function. Single radios will either change bands if the coverage for 2.4 is good but 5 is bad, or a radio will turn into an air monitor if the coverage is over the acceptable value for a band. So with mode-aware arm, a dual radio AP could be serving one band on a radio, the other radio could be an air monitor, or a single radio model would just turn in to an air monitor, until the coverage drops below the 'acceptable' index, and it will start serving wireless access again.

What kind of deployment do you have? Are they all in hallways, single room, multiple rooms with walls/glass separating the areas?

Also, if they can live with it for two months, it's all going to change drastically when you move. I would probably avoid the 134/135 models, they cost nearly twice as much as the 104/105 model, and while they are 3x3 mimo instead of 2x2, they don't put out as much power, and we've found that their coverage is lacking compared to the 105's. We've now limiting their use to areas where the density is higher like conference rooms, where there will be a higher number of clients but much less room to cover. And that's only for the 135's we still have left, at all new sites we are simply installing ap105's everywhere, and using ap93's as dedicated air monitors.

We do not use the mode aware arm since we have dedicated air monitors. The only thing that sucks with that is that the ap93's still take a license.....and we deploy in a 5 to 1 ratio, with most air monitors deployed around the perimeter of the building and a few scattered around inside.

Take a good long look at the ARM documentation, it's a real good resource on how the aruba os does its calculations, what values do what, etc.
 
That's some good info...

Unfortunately we purchased our unit as Alcatel rebadges from our supplier....so we don't have a official login to the aruba support site. I've joined the Airheads community and pulled a couple of documents off of google, but that's what I am left with.

Support from our vender is about 30% of what it should be and they are more interested in doing it themselves and getting paid for it.

If you have access to more/better documentation and are willing to share, I'd sure appreciate it. Our APs are "all of the above": 2 In hallways, 2 in open spaces above cubicles, 1 in a room with 3 walls and 1 glass wall.

I am currently using arm aware mode. The single AP 134 will be in a conference room with approximately 180 people in it.

We're looking at $630 per AP105 and about $800 for a single AP134

Best thing I've found in the way of documentation so far is this: http://www.arubanetworks.com/wp-content/uploads/DG_Roaming.pdf
 
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