This is not a vendor invite to "educate" me. Please, no vendor calls.
As we play with a couple of the major players' 11n stuff (and a couple of consumer grade units for giggles)- am seeing a definite trend. Wondering if others have seen the same. I know of the many variables of wireless in general, and specifically with 11n, but despite all of that I'm still a bit surprised over these. The quick setup: - wide channels only - 5 GHz only, 2.4 radios disabled - Channels are not interfering between hardware sets - Where it can be toggled in hardware, SGI is in use - All clients tested close to each AP, and with a wall or two between - 2 X 3 and 3 X 3 in use - Variety of clients- XP/Mac/Vista on WPA2/EAS/PEAP-MSCHAPv2- no-NAC connections - In-house speed test utilities and FTP transfers used in early testing What seems strange, in general: - The wild inconsistency of data rates. On the new Mac versions you can see data rate, channel, associated AP by doing "alt- click on radar icon". If you do this repeatedly from several different Macs, they all show data rates that fluctuate between 300 Mbps and very low rates- like 6 Mbps. Doesn't matter of you have straight on LOS or walls and multipath, and regardless of what hardware set you're using, this fluctuation can be shown at will - Actual throughput in the 11a/11g world is typically slightly under half of the stated date rate in conversation and function. I'm seeing 11n is more like 1/3 (or less)- if client data rate is stated as 300 Mbps, throughput is at best around 110 (or 100, or 90) on interference free channels- regardless of hardware set - From the same spot, download/upload speeds can very wildly- test after test might be different (stated data rate of 300, typical throughputs of 60 Mbps up/90 down, 110/ 80, 70/75, 113/90, 60/65, 100,58, etc) from same client, and all clients tested act the same way- wildly variable I don't consider any of this "controlled" testing yet, and am just now starting to get ready to do for-real testing as we slowly advance toward 11n. But wanted to float these observations and see if others have found similar variability and have drawn conclusions about it. -Lee Lee H. Badman Wireless/Network Engineer Information Technology and Services Syracuse University 315 443-3003 ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
