Thanks for the link. I forgot all about that tool. FWIW, I entered the parameters for a few buildings we designed recently and I think the settings produced by the tool would be quite serviceable. If I didn't have time for a thorough survey I would be willing to go with these. That said, I think it still leaves some performance on the table. Some observations:
-The resulting configs have fixed Tx power. -It uses ARM to set power, so the min Tx power is 3 dBm instead of 0. -It modifies the coverage indices, which answers my question in an earlier email regarding how to figure out an appropriate value. -It does not adjust Rx sensitivity -All configs had a 12 Mb/s minimum, basic, and beacon rate. In my opinion (and it's exactly that, an opinion), the configs are good (MUCH better than defaults,) but an experienced professional can do better. Chuck -----Original Message----- From: Frank Sweetser [mailto:[email protected]] Sent: Thursday, August 13, 2015 5:28 PM To: Chuck Enfield <[email protected]>; [email protected] Subject: Re: [WIRELESS-LAN] Exclusive 2.4 Ghz and 5 Ghz SSIDs I've heard good things about this specific Aruba solution, which at least aims to give a set of environment specific tuning settings: https://ase.arubanetworks.com/solutions/id/75 (I believe an Aruba support login is required to view) ---- Sent from my Android device with K-9 Mail. Please excuse my brevity. On August 13, 2015 5:15:21 PM EDT, Chuck Enfield <[email protected]> wrote: >I suspect you're that ARM can be made to work, but the question is how >to do it. Aruba doesn't tell you what the various indices should be, >they just say that they vary with deployment density. Ask the question >on Airheads and you get: > >"95% of the time you do not have to change those parameters. An >explanation of ARM parameters is here:" and then a link to the users' >guide ARM section. >That from an Aruba employee. > >Also, ARM won’t adjust the Tx power down to 0 dBm, which I find is >often the right 2.4 Tx power for really dense deployments, such as >classroom buildings where there's an AP in almost every room. 0 dBm >must be set in the radio profile. > >Before Client Match I considered abandoning ARM entirely. Client Match >and Mode Aware definitely make it worth keeping though. > >-----Original Message----- >From: James Michael Keller [mailto:[email protected]] >Sent: Thursday, August 13, 2015 4:05 PM >To: Chuck Enfield <[email protected]>; [email protected] >Subject: Re: [WIRELESS-LAN] Exclusive 2.4 Ghz and 5 Ghz SSIDs > >On 08/13/2015 03:40 PM, Chuck Enfield wrote: >> Just to be clear, we don’t have to do these things to make wireless >> work. It makes it work better. But it is sometimes necessary to >make >> wireless work acceptably in the most challenging environments. That >> said, left to defaults Aruba’s ARM also adjusts 2.4 GHz Tx power way >> down. So far down, in fact, that coverage gaps show up. It also >tends >> to keep power higher on busy APs and lower on less busy ones. In >some >> cases the power on the 2.4 radio will be the same as the power on the >5 >> GHz radio. These characteristics forces us to configure a range of >> acceptable power levels for ARM to choose from. Once you’re doing >that, >> why not select the optimum power levels? >> >> While I’m no expert on Cisco wireless, I have assisted some >departments >> with problems on their Cisco infrastructure. Based on that limited >> experience, I have far less confidence in RRM than you seem to. >> > >The main issue is the defaults for Aruba are for coverage networks, not >high density (30-40 ft) or very high density (30 Ft or less). You >need >to adjust the coverage index min/ideal for high density deployments so >ARM will power down to Min TX powers without shutting down the 2.4 GHz >radios due to CCI (even with edge detection for the APs the default >will >still end up with only a few 2.4 GHz APs). If you set Tx Min/Max to a >6dBm range the APs can power to around double the cell size for >coverage gaps if a radio is down. > >I also like to set the 5 GHz Tx Min/Max range at least 3dBm higher then >2.4 GHz because of the unattenuated propagation distance and better >attenuated penetration. Which also helps duel band devices make better >selections. However most devices have a fairly generous threshold on >AP signal drop before they even try and probe for candidate APs to >associate to. That's really where the controller based client stearing >solutions come in to play with selective acks or the probes to get the >client on the best AP regardless of what the client wants based on just >Rx signal. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
