Garry, It's world-mode (config 802.11a world-mode) and not DTPC (config 802.11a dtpc) that influenced the Mac client power bug on 5G, but the point is correct that the latest 5.2 (which has a controller setting now for world-mode) and 6.0 (does not have the setting) seem to have resolved the issue so the need to disable world-mode is no longer needed.
The Mac initially prefers the 2.4G radio over 5G (given same SSID) unless the RSSI is compelling enough for it to do otherwise, and this is unlikely if the source of the two are from the same AP. I have however noticed that our Macs in the residential halls will transition from 2.4G to 5G if they've been stationary for a certain amount of time, and may suggest that there is some logic behind the scenes. That said, if "remember networks" is enabled, and say a Mac Laptop was last on a 5G radio when put to sleep, it does seem to attempt a connection to 5G when awaken. You can influence the Mac's behavior by modifying the pref's file, and removing all 2.4G references and including just 5G information. Unfortunately, once it connects to 5G and scans again, it will insert the 2.4G information it finds back into the prefs file. If you want the Macs to stick with 5G, then you'll need to create a different SSID from the 2.4G e.g. main-a, main-g so that it will always be on 5G. Jeff >>> Garry Peirce <[email protected]> 11/2/2009 8:47 AM >>> To follow up on a previous posting, I'd heard back from Cisco re: world-mode/DTPC. The SE had inquired with the system engineering group. They reported that they had not experienced any issues with MAC clients since they upgraded to the latest release of 5.2. They have therefore left DTPC at default. Which is how I have left it although I run 6.0.182. In that thread, there was also talk of an Apple/Broadcom driver bug. Reviewing that, it looks to me like there may still be an issue in selecting an available 5G radio. I have a Mac running 10.5.7 using a Broadcom based card w/driver 50.10.38.35. If I disable my 5G radio on a Cisco LW AP (1142 running 6.0.182), the client immediately re-associates to the 2.4G radio. When I re-enable the 5G radio, the Mac remains connected to the 2.4G service. I have to disable/re-enable the Mac's Airport card to regain connectivity to it where it will then immediately connect (bonding channels 64/63 and using the 800ns SGI). The plist file does appear to record the 2.4G channel used but not 5G channels. Does anyone know if this is an intended behavior or if the Mac should prefer the 5G over 2.4G radio? -- > -----Original Message----- > From: The EDUCAUSE Wireless Issues Constituent Group Listserv > [mailto:[email protected]] On Behalf Of Garry Peirce > Sent: Thursday, October 15, 2009 5:11 PM > To: [email protected] > Subject: Re: [WIRELESS-LAN] Self-assigned IP on Macs > > Perhaps I was erroneous in equating the two through a Cisco doc > referencing > DTPC to world-mode. > 'When you enable Dynamic Transmit Power Control (DTPC), access points > add > channel and transmit power information to beacons. (On access points > that > run Cisco IOS software, this feature is called world mode.)' > > DTPC does appear to be CCX related, so it is likely irrelevant with > regard > to the mentioned Apple/Broadcom bug. > > Running 6.0.182, > 'config 802.11a world-mode' is not an available option. > 'config 802.11a dtpc' is. > 'show 802.11a' will show the status of DTPC. > > I'll inquire w/Cisco. > > > -- > > > > > > -----Original Message----- > > From: The EDUCAUSE Wireless Issues Constituent Group Listserv > > [mailto:[email protected]] On Behalf Of Matt Grover > > Sent: Thursday, October 15, 2009 2:51 PM > > To: [email protected] > > Subject: Re: [WIRELESS-LAN] Self-assigned IP on Macs > > > > It's under: > > > > show 802.11a(or b) > > > > -Matt > > > > Bob Richman wrote: > > > So, how about the show command that displays the current setting? > > > > > > -----Original Message----- > > > From: The EDUCAUSE Wireless Issues Constituent Group Listserv > > [mailto:[email protected]] On Behalf Of Matt Grover > > > Sent: Thursday, October 15, 2009 1:21 PM > > > To: [email protected] > > > Subject: Re: [WIRELESS-LAN] Self-assigned IP on Macs > > > > > > Actually, if you are talking about specifically "world-mode" it's > > under: > > > > > > CLI: config 802.11a world-mode > > > or config 802.11b world-mode > > > > > > -Matt > > > > > > > > > -- > > ------------------------------------------------------------ > > Matt Grover === University of Florida > > Sr. Network Engineer === http://net-services.ufl.edu > > [email protected] === Florida Lambda Rail > > (352)273-1061 === http://www.flrnet.org/ > > ------------------------------------------------------------ > > > > ********** > > 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/.
