The overnight issues on Wednesday affected some international internet, streaming or gaming services, a spokesperson said.
"Access to those platforms and websites remains stable. However, we encourage customers to contact us if they have other issues they require assistance with," the spokesperson said, adding that regular updates would be provided in the event of any further issues.
UPDATE @ 8:00PM AEST: Access and performance of websites and applications continue to remain stable. We appreciate your patience as our tech teams continue to test and monitor. Next update tomorrow at 10:00am AEST.— Optus (@Optus) May 23, 2019
A spokesperson from Aussie Broadband told iTWire, meanwhile, that the failure of a piece of hardware in Melbourne belonging to Vocus Communications appeared to be at the root of the Internet issues dogging a number of providers on Thursday.
Contacted for comment, a Vocus spokesperson said the provider had no live incident notifications at the moment.
Many providers appear to have been forced to use back-up links, leading to very slow ping times.
The spokesperson for Aussie Broadband told iTWire: "[The] latest update is that the team think they've narrowed it down to a piece of hardware with Vocus in Melbourne (which may explain why other ISPs seem to be having some issues as well).
"We've re-routed traffic which means most services are now back up and running, but the fault is ongoing in the background and we're going to try a software upgrade shortly to see if that will provide a permanent fix."
Around afternoon the issues that appeared to be dogging the loading of sites hosted in the US or using peering arrangements with US providers seemed to settle down.