Bigpond's NSW users were unable to get online and had trouble getting through to its general enquiry line or technical support.
A Bigpond spokesman told CRN users were back online by 3:40 pm.
But Telstra didn't know what caused the outage.
"At this time we are trying to work out what the problem is," a Telstra spokesman said.
"We have been focused on getting customers back online."
Issue: 303 | May
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