Mobian 'HotSpot"

[TRS-80]

As someone who played cat and mouse with telcos for many years not wanting to be gouged extra for a feature which was built into the OS ("hotspot/tethering") I can tell you it doesn't need to be anything fancy like DPI.  I recall one case where (T-Mobile I think?) were just looking at the TTL hop count on the packets coming on to their network, one less hop and they assumed the packets to be coming from a tethered device.  So the workaround in that case was to simply set TTL to +1 on your devices.   

I do tether a lot recently and it works mostly but the data connection keeps dropping out.  I am not on Bookworm yet though, my hope is that continued software development of the modem stack will improve reliability.