Telstra customers across the country are experiencing major disruptions to their services after a fire disrupted services at an exchange in Sydney.
"None of my staff can make landline calls," said the head of a Perth charity, which looks out for at-risk youth.
"We can't get through to Telstra - the line is busy. People have been trying to get hold of me since 9.30am or so. In fact we are having a new internet line put in at one of our sites and the Telstra technician struggled to contact me.
"We can't contact staff or clients ... we have staff out with youth who won't be able to contact anyone or make an emergency call if they need to."
Meanwhile, personal SMS messages of Telstra customers are being received by phone users of other networks across Australia.
Unwitting recipients of the random messages took to Twitter to express their confusion.
The security breach could have huge implications for the country's biggest telco as online services rely on it for such things as sending password reset links.
Earlier, Telstra announced the location of the fire to be Chatswood Exchange, Sydney, via Twitter.
The outage map on the website www.aussieoutages.com indicates all states and territories are affected.
I could have broken this guy's deal wide open lol RT @JustJen64: @Telstra WOW LOTS OF ISSUES THERE TELSTRA ...
— Iggy Busby (@IggyBusby) February 2, 2017
PRIVACY ISSUES FOR ONE.. pic.twitter.com/Uh5v8BG8uL
From unkn number, @Telstra outage causing some curious crossed wires. I hope this person gets the trifle they crave in time for tomorrow... pic.twitter.com/JhRzT7XKg1
— Anna Riddell (@a_r_riddell) February 2, 2017
A fire at one of our exchanges is impacting some mobile and fixed services. We're working to resolve ASAP. Thanks for your patience.
— Telstra (@Telstra) February 2, 2017
Screenshot from outage website aussieoutages.com showing affected areas.