For clarity the ‘real’ (not DIY, but DIY generally do also) alarms have battery backup and communicate with the central station (for perimeter intrusions and fire) by the GPRS wireless (eg mobile) service since NBN VOIP does not support the old school diallers (NBN official position).
Some alarms can be equipped to use internet reporting (in lieu of GPRS or diallers). Video usually requires internet for remote viewing. GPRS has apparently become the new gold standard for reliability (unless you have a single SIM system and Telstra/Optus are doing unannounced maintenance when it fails miserably - been there, experienced that on a routine handshake failure). Those so worried can buy dual SIM (1 Telstra and 1 Optus) that would be as reliable as it gets, at extra monitoring cost.
Because of police response protocols (differ in each state I believe), a reason to have video in Victoria is that it is illegal for a Central Station to ring the police without verifying an intrusion or fire - hence video or sending a guard if they could not reach you. OTOH a mere citizen can ring straight away.
It depends what @White57 needs and wants.
