Experts and advocates have demanded changes to how telecommunication companies are regulated and held accountable for outages after Telstra became the latest telco to suffer a large-scale network failure.Telecommunications industry expert and RMIT University associate professor Mark Gregory said recent high-profile outages proved Australia's "fragile" telco networks were not up to the job of always providing reliable phone and internet services.Dr Gregory said national outages should not happen and questioned whether Telstra had done enough to ensure its network was resilient."An outage that takes down a national network is something that should not occur in this day and age," he said."We should have resiliency and reliability From time to time, issues do occur."He was asked again about this at a second press conference on Tuesday evening where he said Telstra had failed the public but should still be trusted.In a statement, Telstra said its network was built "with multiple layers of resilience, including redundant core network systems, geographic diversity across key network elements, backup power systems, diverse routing and 24/7 operational monitoring"."Our network is designed to minimise the risk of single points of failure and to restore services as quickly as possible when disruptions occur."