I have a Huawei E3372h-153 attached on a RB2011UiAS-2Hnd in HiLink mode. The router gets an IP address from interface lte1.
Problem is that the lte1 link goes up and down repeatedly. The lte1 interface also disappears. I placed an old USB 1.1 hub between and the lte1 link stays up. Can it be a USB power problem?
Update: also tested with a USB 2.0 hub, lte1 interface stays up. But with downloading files the connection drops. Only way to get E3372 working again is USB power reset. I think the E3372 needs more power then the Mikrotik can deliver?
If those two USB hubs you’re mentioning are powered hubs, then your experience indeed indicates USB power problem. Or, to be exact, insufficient power over RB’s USB port.
My experience is that many (if not all) USB modems draw more power than specified by USB (1.1. or 2.0) standard (0.5A at 5V is merely 2.5W … even if peak power draw of a device exceeds that, it might overload USB port). A decade (or two) ago, such USB sticks came standard with a special Y-cable which would connect data lines to single USB connector while power lines were connected to two USB connectors and would thus draw power from two USB ports.
Both USB hub where non-powered. I ordered a USB powered hub, will let you know if it works.
Update: The E3372 works with a USB 2.0 powered hub, no problems with losing connections