A Friday morning outage is quickly turning into a full day outage, with some Optus customers left without mobile or fixed connectivity.
"Optus is aware of an outage that may be impacting Optus services. We are aiming to restore these services as a priority," the telco tweeted at 11:04am AEST on Friday
"We thank customers for their patience and will provide an update as soon as possible."
Over three hours later, Optus customers are still waiting for more information.
A spokesperson for the company said the outage began at 10:30am AEST, and it was looking into the cause.
At the time of writing, the Optus service status page did not return outages at tested addresses, but did report outages across Sydney on mobile.
"Sorry, a number of Optus mobile towers in this area are not working," its notice stated.
"Our network team is working to resolve a transmission issue on the Optus mobile network in this area."
By 4:34pm, Optus said it had restored 4G and 5G services, but 3G was still experiencing issues. On Saturday, the company said everything was restored.
On Thursday, Optus claimed to have the fastest 5G upload speeds in Australia when it used millimetre wave (mmWave) spectrum to hit 300Mbps. Combining with Nokia, the test utilised both 4G 2100MHz and 5G mmWave spectrum and Casa Systems premises equipment. "Let's say you have a 500MB video file; on current 4G networks that may take around 1 min 30 seconds to upload which is already fast, but with upload speeds in the vicinity of 300Mbps the same task can be completed in less than 20 seconds," Optus managing director of Networks Lambo Kanagaratnam said.
"For us it's important that we are connecting customers with technology that improves their lives and increased upload speeds on mmWave 5G is really going to save time for both businesses and consumers as it's rolled out over the coming months."
The company has six sites using millimetre wave, and 1,300 sites on its 5G network. Update at 4:42pm AEST, July 2: Added Optus update. Update at 11:00am AEST, July 4: Further Optus update.