When the H.

The MG reports availability and restarts to the MGC using H.248 ServiceChange with Method=Restart. The Reason code distinguishes the type of restart. In Huawei implementations aligned with H.248 semantics, Reason=[901] corresponds to a warm/warmboard restart scenario rather than a full cold start.

Board restart triggers a warm restart of the voice board/MG, producing ServiceChange { Method=Restart, Reason=901 }.

Reset coldstart performs a cold start, which would use a different reason code (cold start), not 901.

Reboot system generally implies a broader device reboot similar to cold start semantics, not 901.

ONT re-register affects ONU registration and does not cause the MG to announce a ServiceChange restart to the MGC.