Hi,
Has anyone being able to connect a GSM SIM to 3CX a simple .i.e. Callers that call the GSM number are answered on the PBX and calls to GSM can be routed through the GSM SIM ????
A google search for '3cx gsm gateway' produces several results. The forums have several posts as well. The only 3CX supported device is the Beronet as listed here: https://www.3cx.com/voip-gateways/beronet-berofix-400/
But any SIP standard/compliant device can be made to work with 3CX as long as you understand SIP and how to troubleshoot.