Hello Tony,
At least with the RUT 950 and every Teltonika device that doesn't have 2 modems, this is not possible, because you can't use both SIMs at the same time. What the router does is switch between SIMs and only use one at a time and in case one SIM gets disconnected the router changes to the backup one or in case you have configured a rule based on a data limit it would change to the other SIM.
