Hi Sam- Great stuff. Point of clarification: I’m not trouncing RRM wholesale, not at all. We use it and generally it is a force multiplier and quite good. But… there are scenarios where it doesn’t do so well and that’s where it can’t read your mind. Like RRM doesn’t know in spots that you were stuck doing down the hallway builds, and so can be too aggressive in lowering power. I’ve found in some single-room dense environments it can be wonky as well, especially if your “OK, now change yourself as you see fit” interval is too short. For critical auditoriums, bypassing RRM has been a gain for me… But I also get why people use it end to end and say if it works for you, rock on.
Nice to see you on the list, Old Man. -Lee From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Samuel Clements Sent: Wednesday, January 13, 2016 11:14 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] high density wireless improvement features Hi all! I'm new to the list (well, I've been lurking for a while), but this seems to be a good time to say hi! High Density being near and dear to my heart - I'd give the following guidance: 1) Don't underestimate your gear if you have good equipment. It's not a stretch for a Cisco 2700/3700 to support 100+ active association (shameless self-plug: http://nsashow.com/AP2700/). 2) There is such a thing as too much RF. If you're not disabling all but 3 2.4GHz radios in a single room, you're not disabling enough of them. If you see two APs on the same channel (as a general rule) and they're both above -80dBm, you're not adding any capacity to your RF. In fact, you're hurting yourself. 3) Use narrow channels in 5GHz (20MHz), always. There is an overwhelming need for density of users (aggregate throughput), not individual throughput. This is one of the best ways to leverage the finite amount of air we have to use. 4) Use all channels in 5GHz including 2e/DFS channels. The more channels the better. If you're using a sane RRM product (Cisco does this for sure), RRM will try to avoid stacking 2e channels next to each other. In the event you have a client that doesn't support a channel you're using, this improves the likely hood that they can still function on a further AP. 5) Once you hit a number of APs that matches the number of 5GHz channels you have deployed, be very cautious about channel overlap (this is the same as rule 2, just in 5GHz and further away). 6) Design for RRM and enable RRM (sorry Lee!). If you know how RRM works (there are many and numerous white papers and Cisco Live sessions on the specifics of how AP layout impacts RRM), you can safely run it without shooting yourself in the foot. I can't speak to ARM since there doesn't seem to be a good guide on how it actually works. 99% of the time, RRM works every time. The great thing about Cisco RRM is that you can watch the CLI of the process and it will tell you exactly what it's doing and why it's doing it. Use min and max thresholds if you can't get it to do what you'd like. 7) Use RF Groups to segregate your high density areas from other areas of your campus. This allows you to tweak and tune your HD area without impacting other users. 8) Use RX-SOP only when you've violated rules 2 and 5 and use it sparingly. RX-SOP is like a brick wall. Once you hit it, your clients fall off into never never land. I hope that helps! There is a ton of guidance that can be given for designing cells (using directional antennas, stadium antennas with narrow beams from far away, APs under seats, in walls, etc) but those are covered in great detail elsewhere and all of the above advice can be taken regardless of antenna or location of installation. -Sam On Tue, Jan 12, 2016 at 11:00 PM, Tariq Adnan <t.ad...@unsw.edu.au<mailto:t.ad...@unsw.edu.au>> wrote: Hello everyone, I am working on improving wireless performance in high density areas (lecture theaters, auditoriums etc) and doing research on some features. I would like to know if you people have made below changes and how was your experience with it ? We're using cisco gear (3702i/e APs, WiSM2 controllers, Prime 3.0). 1-set channel and power manually (not use RRM) : reduce power to limit coverage and disable 2.4GHz radios on every 3rd/4th AP. 2-load-balancing 3-band-select 4-RX-SOP (already deployed and happy with it, channel utilization is dropped) 5-optimized roaming 6-please suggest if i am missing something In our setup, same controller is handling APs from HD and non-HD (high density) environments. My concern is if i make change which is controller wide, for instance optimized roaming, it could improve performance in HD areas but what could it do to non-HD areas (APs far away from each other). I am using airmagnet PRO and Prime planning tool for survey and planning purposes. Thanks everyone for your precious time [😊] Cheers, -- Tariq Adnan Network Engineer NSW, Australia ********** 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/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
