Telstra has again been hit by widespread network outages, infuriating customers just a day after the telecommunications giant's chief committed to improving customer service and boasted of the network's "incredible strength and resilience".

Users vented their frustration at being unable to use their NBN and ADSL voice and data services, with problems appearing to have started at midnight, according to monitoring website aussieoutages.com.

Telstra has been hit by another service outage. Credit:Louie Douvis

Complaints spiked again about 7.30am on Friday, with reports mostly coming from Melbourne, Brisbane, Perth, Sydney, Adelaide and a number of regional centres.