Widespread problems with Telstra's ADSL (asymmetric digital subscriber line) network recently disrupted the service over a 15-hour period.
All ADSL sessions in New South Wales, South Australia, Australian Capital Territory, Western Australia and Tasmania were disconnected and new users were blocked from logging on.
Problems persisted for more than three hours, although many customers who made repeated attempts to log on might have been able to reconnect, a Telstra spokesperson said.
Telstra believed it had rectified the situation, however the same problem surfaced intermittently the next day.
The fault was traced to an interface board and suppliers worked through the weekend to prevent further interruptions, the spokesperson said.
Telstra was concerned the initial problem had recurred on equipment with built-in reset intelligence, she said.
The outage comes at a particularly embarrassing time for the carrier, which is in the midst of a major national advertising campaign promoting its broadband offerings.
Sources close to the situation blamed the lapse on interface problems between equipment from different suppliers.
Specifically, they sheeted it home to an interface glitch between a service management centre product sourced from Alcatel SA and a Shasta Networks server.
The Shasta system, manufactured by a Nortel subsidiary, has been a constant source of irritation for network technicians, the sources claimed.
A recorded message on Telstra's help line ascribed the outage to "network complexities".
It is not the first time the carrier has had technical difficulties with its ADSL network, with subscribers suffering longer outages earlier in March this year after a router dysfunction in Melbourne. Pete Young is a journalist at ARN's sister publication, The Industry Standard.