I believe it's recommended that you upgrade floor by floor, and building by building.
If you don't have that capability, I would suggest upgrading the hardware, but not enable the VHT capabilities until all hardware has been upgraded. I'm not totally sure of .11ac's protection mechanisms, but doing this would also avoid any unforeseen issues of an mixing VHT clients/APs with non-VHT clients/APs. Damien Cameron Network Engineer Norfolk State University Office of Information Technology Marie v. McDemmond Center for applied Research Room 401 555 Park Avenue Norfolk, VA 23504 O: (757) 823-9123 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[email protected]] On Behalf Of Jeff Kell Sent: Sunday, March 16, 2014 1:05 AM To: [email protected] Subject: Re: [WIRELESS-LAN] 11ac migration question Have seen similar results with Dell laptop locking onto 802.11n at a distance and ignoring "same room" a/b/g. We are trying to avoid mixed deployments, and sounds like the same concerns extend to 11ac as well. Jeff On 3/15/2014 11:12 PM, Alok Vimawala wrote: Hi Frank, We just had an interesting incident in one of our buildings where half of the ac radios stopped working. The building has Cisco 3602i APs with the add-on 802.11ac Wave-1 module. So, the building turned into a mixed 802.11n and 802.11ac deployment on the 5GHz spectrum. What we saw in that building was that new Apple MacBook Pros with the 802.11ac capable chipsets were preferring to associated with a bad 802.11ac signal rather than connecting to a great (AP right above the laptop) 802.11n signal. Clients seem to prefer protocols with highest theoretical throughput regardless of signal strength and that behavior hasn't really changed since the days when 802.11n was first introduced. My recommendation would be to avoid mixed 5GHz 802.11n and 802.11ac environments. Thanks, Alok Vimawala University of Michigan On Sat, Mar 15, 2014 at 9:54 PM, Frank Sweetser <[email protected]<mailto:[email protected]>> wrote: Hello all, we're beginning plans to upgrade our wireless infrastructure from 11n to 11ac, and I'm hoping that someone can chime in on their experience with mixed capability buildings. When we first went from 11a/b/g to 11n, we found that clients in buildings with mixed capability APs had some odd roaming issues - and by "odd", I mean utterly braindead. A fair number of clients would aggressively latch onto an 11n AP at -80, while ignoring an a/b/g AP in the same room at -50, with predictably poor results. In the end, we had to ensure that buildings were upgraded in full, rather than incrementally, to fix the complaints. My question is, has anyone seen similar issues in buildings with a mix of 11ac and 11n APs? -- Frank Sweetser fs at wpi.edu<http://wpi.edu> | For every problem, there is a solution that Manager of Network Operations | is simple, elegant, and wrong. Worcester Polytechnic Institute | - HL Mencken ********** 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/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
