The equipment onboard provides both GSM and WIFI service, (so good old SMS works but no calls) as well as WiFi service

The cabin manager/senior is responsible for the equipment which is in the same cabinet as the IFE, (nice big guarded toggle switch). During the early days many years ago there were 2 aircraft in the fleet with different wiring (assuming this was EI-LAX and EI-DUO) and the system fleet wide was left off until it was resolved