George, I do not know the why either. Yes, ePMP delays the time of the on-board GPS to match the CMM4 and if both on-board GPS and CMM3 are present we follow the on-board GPS so that the CMM3 sector can be 1PPS synced with other sectors using CMM4 and on-board.
Dan From: Af [mailto:af-boun...@afmug.com] On Behalf Of George Skorup Sent: Tuesday, June 09, 2015 5:46 PM To: af@afmug.com Subject: Re: [AFMUG] ePMP sync differences CMM3 vs CMM4. So you shift the on-board pulse based on what you see on the power port? That's pretty cool. Walk over and tell the Canopy guys to do that. Stupid question.. why the hell is there a difference between the CMM3 and 4? On 6/9/2015 5:10 PM, Dan Sullivan wrote: Hi Forrest, For ePMP if you are using a CMM3 timing source and you also have the on-board GPS enabled for that ePMP, then this will produce the same timing of the on-board GPS alone or the CMM4 alone (or the CMM4 and the on-board GPS enabled). Hopefully, this will provide you the flexibility you need. Daniel Sullivan ePMP Software Manager Cambium Networks Cambium Networks Community Forum<http://community.cambiumnetworks.com/> From: Af [mailto:af-boun...@afmug.com] On Behalf Of Brandon Yuchasz Sent: Wednesday, June 03, 2015 10:44 PM To: af@afmug.com<mailto:af@afmug.com> Subject: Re: [AFMUG] ePMP sync differences CMM3 vs CMM4. Forrest, What’s the down size of making the change for you? Best regards, Brandon Yuchasz GogebicRange.net www.gogebicrange.net<http://www.gogebicrange.net/> From: Af [mailto:af-boun...@afmug.com] On Behalf Of Forrest Christian (List Account) Sent: Wednesday, June 03, 2015 3:22 PM To: af Subject: Re: [AFMUG] ePMP sync differences CMM3 vs CMM4. I agree...buy lots of packetflux gear instead. ;) I guess my implied question was more: "Since the ePMP seems to treat the internal GPS and CMM4 timing identically, and the syncinjectors produce CMM3 timing which creates additional complications in mixed internal GPS/Syncinjector network, is there value in me bothering with a switch to switch between CMM3 and CMM4 timing in the syncinjectors?". The situation I see is where you have a network with syncinjectors, and for whatever reason the sync source fails on one of the injectors. You go into the ePMP and tell it to use the built-in GPS. Now you're in the situation that you have to go and mess with front and back settings to match the recommendation in the manual since the AP's you just switched are now on the opposite timing. If the syncinjector could be set to CMM4 timing, this wouldn't be necessary - swap the sync source, and you're still good to go. -forrest On Wed, Jun 3, 2015 at 2:13 PM, Josh Luthman <j...@imaginenetworksllc.com<mailto:j...@imaginenetworksllc.com>> wrote: >Thoughts? Don't buy a CMM4. 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 On Wed, Jun 3, 2015 at 4:07 PM, Forrest Christian (List Account) <li...@packetflux.com<mailto:li...@packetflux.com>> wrote: On the cambium ask the synchronization experts thing I'm doing someone pointed out the section in the ePMP manual talking about frequency reuse. I had to go look since I had somehow missed that section. In case you haven't seen it, there's a deep discussion about the proper settings when you have a "mixed" network of internal GPS, CMM3 and CMM4. (See Page 94 in the current release). I admit my ignorance and I hadn't seen this yet, but..... All I have to say is this: WTF Cambium? Ok, I know the dirty little secret that the CMM3 and CMM4 produce different timing pulses. Obviously different enough that it matters in the ePMP world. But the difference is easy enough to fix... add a fixed amount of delay which varies based on the timing source. They already have to delay the GPS timing signal to match the CMM4. Why not delay the two sources which are 'early' to match the 'late' source? Or even better, fix the CMM4 so it matches every other sync source on the planet - I'm shocked this hasn't already been done. Ok, I get it, it might be a hardware limitation which prevents one or both of the solutions. But come on, really? For the record the syncinjectors currently produce "CMM3" timing, not "CMM4". Since it's obvious that the difference matters now, I'm considering adding a software witch which allows this to be configured so you don't have to deal with a 'mixed' timing source since it seems like a CMM4 and internal GPS are identical. This should permit better operation when you have to switch between an internal GPS and a SyncInjector. Thoughts? -- Forrest Christian CEO, PacketFlux Technologies, Inc. Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 forre...@imach.com<mailto:forre...@imach.com> | http://www.packetflux.com<http://www.packetflux.com/> [https://s3.amazonaws.com/images.wisestamp.com/icons/linkedin.png]<http://www.linkedin.com/in/fwchristian> [https://s3.amazonaws.com/images.wisestamp.com/icons/facebook.png] <http://facebook.com/packetflux> [https://s3.amazonaws.com/images.wisestamp.com/icons/twitter.png] <http://twitter.com/@packetflux> -- Forrest Christian CEO, PacketFlux Technologies, Inc. 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