Josh, Good question from yesterday as it started an internal discussion. Let me give some more details as my “No” answer is not as black and white as I indicated.
When running TDD mode based MAC interfaces (e.g. 5 msec, Flexible, and now 2.5 msec), the AP defines the content and timing of each frame which includes when each SM in the UL can transmit. Therefore, as long as the SM does what it is told, this provides a great deal of compatibility between releases. For 2.5 msec frames from a 2.5 AP, a 2.4.3 SM will work in 75/25 and 50/50 modes, but not with the same performance as a 2.5 SM. A 2.4.3 SM will work in 30/70 mode as long as at least one 2.4.3 SM does network entry right when the AP first comes up, but the 2.4.3 SM will not work if it does network entry later and there were no 2.4.3 SMs that did network entry when the AP first came up. The 2.4.3 SM will be at a performance deficit compared to a 2.5 SM. There was no QA testing done between the 2.5 AP in 2.5 msec mode <-> 2.4.3 SM. It was done with 2.5 AP in 2.5 msec mode <-> 2.5 SM. Therefore, there is a greater chance that something could not work in the 2.5 AP in 2.5 msec mode <-> 2.4.3 SM. My recommendation is similar, upgrade your SMs to the 2.5 release first and then set the AP to 2.5 msec mode. And yes, there was some intentionality to the 2.5 release containing the 2.5 msec feature ☺ Dan From: Af [mailto:[email protected]] On Behalf Of Josh Luthman Sent: Wednesday, September 09, 2015 5:14 PM To: [email protected] Subject: Re: [AFMUG] ePMP AP running 2.5 ms - station firmware requirement Thanks guys!!! Josh Luthman Office: 937-552-2340 Direct: 937-552-2343 1100 Wayne St Suite 1337 Troy, OH 45373 On Wed, Sep 9, 2015 at 6:13 PM, Dan Sullivan <[email protected]<mailto:[email protected]>> wrote: Josh, No. 2.4.3 stations cannot support 2.5 msec frames. You will need to upgrade your stations to the 2.5 release and then they will be able to listen to an AP configured to 2.5 msec frames. Daniel Sullivan ePMP Software Manager From: Af [mailto:[email protected]<mailto:[email protected]>] On Behalf Of Josh Luthman Sent: Wednesday, September 09, 2015 5:08 PM To: [email protected]<mailto:[email protected]> Subject: [AFMUG] ePMP AP running 2.5 ms - station firmware requirement I'm wondering if my stations at 2.4.3 can talk to an AP doing 2.5ms frames. Does anyone know? Josh Luthman Office: 937-552-2340<tel:937-552-2340> Direct: 937-552-2343<tel:937-552-2343> 1100 Wayne St Suite 1337 Troy, OH 45373
