Optus parent Singtel hit back at claims a routine software update from its internet exchange (IX) unit was the root cause of a massive outage that affected the Australian operator last week.

In a stock market statement, the Singaporean company asserted the upgrade conducted by Singtel Internet Exchange (STiX) had not been behind the issue.

Instead, it deemed “pre-set fail safes” of Optus equipment as the problem.

Earlier this week, Optus pointed to technical issues related to its routers following a software upgrade as the cause of the issue, which has caused a political and media storm in Australia.   

Although the under-fire operator did not name the third party provider behind the update, The Sydney Morning Herald outed Singtel Internet Exchange (STiX) as the supplier. Media headlines in the country largely blamed the software change for sending the network down.   

Responding to media reports, Singtel explained: “During the upgrade, data traffic was routed to other points of presence on the STiX network and back into customers’ networks. The STiX upgrade was completed within 20 minutes and all its customers’ routers that were connected to it, including Optus’, were up and running.”

“We are aware that Optus experienced a network outage after the upgrade when a significant increase in addresses being propagated through their network triggered pre-set fail safes. However, the upgrade was not the root cause.”