My challenge, as I’ve stated on this list before, is that Mac OS X preferences width in its AP selection criteria. So while you may get more capacity, in a large Mac environment you lose most of that with Macs hanging onto APs linger and having to rate-shift down to slower PHY speeds due to that AP having a wider channel than its neighbors. Yes, it’s dumb. But he’s the driver of that lambo.
Also, couple that with increasing the noise floor by 3db every time you double the channel width and there are many cases where your lambo just spins it’s tires. All that power and you can’t hook it up. Remember that spectrum is our constraining resource. Figure out what width of channel you can run in a building, and run that. That’s the best use of spectrum and sure to give you the most smiles/hour on your lambo. I really like what cisco did with FRA. Give me the ability to see what it thinks the overlap is. I would LOVE to see the same with DBS, and give me what width it thinks all the APs in the building can pull off. Sent from my iPhone > On Sep 26, 2017, at 8:19 AM, Jeffrey D. Sessler <[email protected]> > wrote: > > It’s surprising to me that anyone would purchase a Lamborghini, then > disconnect ten of the twelve cylinders and drive it at 25 mph on the autobahn. > > When I see static 20 MHz channels, or using 40 MHz in only limited areas, I > wonder what’s behind the purposeful neutering of the system. If you are a > Cisco customer running 8.1 or above, and not using DBS (Dynamic Bandwidth > Selection), then it’s the equivalent of the Lamborghini above running on only > two cylinders. > > Don’t miss out on the significant advancements in bandwidth management. Free > those resources spent doing point-in-time simulation and surveys for > something the software doesn’t already do far better at. I promise, DBS won’t > hurt a bit and your users will thank you a hundred times over. > > Jeff > > > From: "[email protected]" > <[email protected]> on behalf of "Street, Chad A" > <[email protected]> > Reply-To: "[email protected]" > <[email protected]> > Date: Tuesday, September 26, 2017 at 6:59 AM > To: "[email protected]" <[email protected]> > Subject: Re: [WIRELESS-LAN] Two RF Questions > > What is your reasoning behind not wanting 40 megahertz channels if you have > plenty of overhead with your channel utilization? People saying you should > or should not do something without Gathering any type of metric worry me. > > On Sep 25, 2017 3:28 PM, Chuck Enfield <[email protected]> wrote: > 1. Enable it in places to check for radar events. If you get few, then > yes. Client devices are almost fully capable now. Hidden SSID’s are the > only issue. Some clients don’t probe on DFS channels, and will only respond > to beacons. Make sure 2.4 is usable for the small number of incompatible > devices. > > 2. No. Don’t even consider 40MHz unless you’re using almost all the DFS > channels, but even then you’ll probably have to disable it in some high > density areas. > > > > From: The EDUCAUSE Wireless Issues Constituent Group Listserv > [mailto:[email protected]] On Behalf Of David Blahut > Sent: Monday, September 25, 2017 3:17 PM > To: [email protected] > Subject: [WIRELESS-LAN] Two RF Questions > > > > Greetings, > > I have two hopefully simple RF related questions: > > 1. Should I enable the extended UNII-2 channels campus wide? > > 2. Should I enable 40Mhz channel width campus wide? > > In other words what are you doing on your campus and what is the "best > practice? > > > > Our wireless infrastructure: > > > > 3 Cisco 5508s running 8.2.141.0 > > > > 20 - 3800 APs > > 368 - 3700 APs > > 414 - 3600 APs > > 8 - 3500 APs > > 7 - 1810 APs > > 32 - 1142 APs > > > > Prime 3.1.0 > > > > Thanks for your input. > > David > > ********** Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/discuss. > > ********** Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/discuss. > > > > This e-mail message (including any attachments) is for the sole use of > the intended recipient(s) and may contain confidential and privileged > information. If the reader of this message is not the intended > recipient, you are hereby notified that any dissemination, distribution > or copying of this message (including any attachments) is strictly > prohibited. > > If you have received this message in error, please contact > the sender by reply e-mail message and destroy all copies of the > original message (including attachments). > ********** Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/discuss. > ********** Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/discuss. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/discuss.
