I have 20 devices collecting data, which use Nova with Hologram SIMs for connectivity. On 24 Dec 2016 there was some kind of disruption event that hit at least 12 of the 20 units. Of these 12, we contacted people who could unplug/reset them, and 10 of them again established connection (we have not yet diagnosed whether the other 2 have hardware issues). Now, today, I notice on the Hologram dashboard that the remaining 18 have no activity since yesterday (I checked at roughly 15:00): this is a concern since I am used to seeing activity reported once every six hours.
I suspect either it is some kind of Internet link problem (which of course is outside our control) or maybe a more local problem with AT&T 3G. Perhaps also our control in the SBC hosting the Nova is not robust enough to automatically recover, though it has served us well most of the time.
My question to users out there, have you experienced this kind of massive disconnect of multiple devices in production?