After doing a little bit more testing for curiosity sake, I can confirm what you were seeing now on my network. We are running 5.0.0.1. I'll upgrade in a couple days and see if that also fixes the problem that I'm seeing. I'm still only seeing it where we have a mix of 2.4 only APs and AP 125's.
Greg Williams IT Security Principal University of Colorado at Colorado Springs -----Original Message----- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[email protected]] On Behalf Of Ethan Sommer Sent: Monday, August 16, 2010 12:30 PM To: [email protected] Subject: Re: [WIRELESS-LAN] Band Steering? FWIW: After upgrading to 5.0.2 from 5.0.0, things fall back to 2.4ghz much better than they used to. I think we still need to do some tweeking to get things working as well as we'd like. Unfortunately, we don't have the kind of budget to just throw out more APs to fix the problem, so that's not really an answer for us. I have to say, I've been really disappointed by Aruba tech support's answer to this sort of thing. 1. The documentation for 5.0.x says to turn on "Local probe response" but that doesn't seem to exist anymore in 5.0, but did in 3.x. 2. In two separate tech support tickets, with two separate tech support people, I was told that "that was just the way the system worked, people couldn't fail back to 2.4ghz." That's A) false, and B) not even what the user manual says. 3. They clearly didn't know that there was (apparently) a bug in 5.0.0 that was fixed by 5.0.2 which allowed clients to fail back more. Ethan On 08/16/2010 06:36 AM, Osborne, Bruce W. (NS) wrote: > Here is a response I received from Aruba Engineering: > > Bruce, > > I have heard this from some of my other customers as well. The basic issue comes down to the physical properties of the 5GHz wave vs. the 2.4GHz. The lower frequency (2.4) will be able to travel through air and walls and even "bend" around corners better than the higher frequency 5GHz wave. For this reason at the edge of an AP's coverage area the 2.4 signal will be better quality than the 5GHz. With band-steering enabled we will keep the client on the 5GHz radio despite a better performing 2.4 signal being available. > > I would prefer to keep band steering enabled and design the RF coverage based on the 5GHz coverage. > > You can add an AP 105 and set the b/g radio as a full time air monitor or you can consider a single radio AP (the AP-93) to provide 5GHz coverage only to these areas where the 2.4GHz can reach but the 5GHz does not. > > Thank you, > > > Bruce Osborne > Liberty University > > -----Original Message----- > From: Ethan Sommer [mailto:[email protected]] > Sent: Wednesday, August 11, 2010 3:30 PM > Subject: Band Steering? > > We are upgrading part of our network using Aruba AP-105s and a pair of > 3600 controllers. > > We've found an annoying problem when we have band steering turned on. > > We've create two SSIDs. Lets call them BandSteering and NoBandSteering. > When users are relatively close to an access point, they can connect to either. My MacBook will usually connect using 2.4 Ghz on NoBandSteering and will always connect using 5ghz to BandSteering. When a user is further away from the access point, however, they can connect fine to NoBandSteering (obviously it is slower than when they were closer) but can't connect at all to the BandSteering SSID. It doesn't fail back to 2.4ghz, and the clients don't recognize that they can't connect and connect to NoBandSteering if that's lower in their preferred networks list. > > The effect is that, understandably, users will select the > NoBandSteering SSID because it is more reliable. (Even though it is > slower in most cases.) > > Aruba suggested that I try setting the 5ghz ARM profile to always max out the 5ghz radio, which helps some but does not eliminate the areas where 2.4ghz works and 5ghz doesn't. > > So, my questions are: > 1. Are people using band steering? > 2. Have you found the same problem? > 3. Is there a way to fix it? (Other than turning off bandsteering.) > > > 4. I suppose a related question is, is there a way to make client computers prefer 5ghz more? > > I guess we'll probably just not use band steering if we can't find a solution, but it would be a shame not to better utilize the 5ghz spectrum better. > > Thanks for any suggestions! > > Ethan > > -- > Ethan Sommer > Associate Director of Core Services > Gustavus Technology Services > [email protected] > 507-933-7042 > > ********** > Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. > > ********** > Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. > -- Ethan Sommer Associate Director of Core Services Gustavus Technology Services [email protected] 507-933-7042 ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
