Telstra's 4G network is back up and running, the telco has confirmed to media.
"Telstra has resolved an issue impacting some 4G voice calls on its national mobile network," a spokesperson said in a statement.
"We are sorry that some customers were unable to make or receive calls as this was occurring.
"The issue was caused by technical changes made ahead of upgrades to mobile traffic control equipment in Telstra's Exhibition Street exchange in Melbourne.
"The issue was progressively resolved by reversing the changes. The issue became known about 1pm and was resolved about 3pm."
Telstra had acknowledged the issue on Twitter[1] earlier on Tuesday afternoon.
"We are investigating an issue with the 4G network and we apologise to customers," Telstra added in a statement to media. "We're working to fix an issue impacting some 4G voice calls. Calls over 3G are unaffected," the telco tweeted.
Australia's incumbent telecommunications provider had similarly suffered a 4G outage in September[2] last year, at the time saying it "very quickly" repaired the issue.
It last year also experienced an outage across fixed-line and mobile services due to a fire at its Chatswood exchange[3], which caused SMS messages to be delivered to the wrong people[4], along with an enterprise voice and data outage caused by faulty hardware[5], which both occurred during February.
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