Floodwaters hampered the repair of an inter-capital link that broke south of Sydney yesterday, causing congestion problems for customers of iiNet and Internode.
Services were restored just before 2:35am AEST this morning.
The fibre optic link, which appeared to be owned by Vocus, was cut between Wollongong and Penrose, between the Illawarra and Southern Highlands regions of NSW.
The cut was identified at 4pm AEST on Sunday, although Vocus indicated in advisories that it had been experiencing core network link failures since about midday.
Vocus said fibre technicians had reached the site but initially "could not access the cable because of flood water”.
Much of the east coast of Australia has been battered by rain and storms over the past week, and the weather pattern is set to continue into this week.
A Vocus spokesperson was contacted for comment.
The route issue affected customers of ISPs iiNet and Internode nationally.
Internode said its customers experienced "higher than usual latency and packet loss” and slow browsing speeds, while iiNet said the domestic link failure “between Sydney and Adelaide [had] caused redundant network links to operate at capacity”.
Both iiNet and Internode came in for similar criticism last year when they were left short of redundant capacity by a planned outage of the Basslink fibre cable.