what caused the optus outage

The Optus outage that occurred on November 8, 2023, was caused by a routine software upgrade that resulted in changes to routing information, which propagated through multiple layers in the network and exceeded the capacity of several routers. As a result, these routers disconnected from the Optus IP Core network to protect themselves, causing the outage. The restoration required a large-scale effort of the team and in some cases required Optus to dispatch people across a number of sites in Australia. The outage affected about 10 million customers Australia-wide for more than 12 hours