Optus is facing millions of dollar in fines over a network outage which impacted triple-zero calls. (Erik Anderson/AAP PHOTOS)Optus is facing millions of dollar in fines over a network outage which impacted triple-zero calls. (Erik Anderson/AAP PHOTOS) Credit: AAPAustralia's second-largest telco is facing legal action over a major network failure that caused a widespread triple-zero outage. The watchdog has previously taken action against the telco following another triple-zero outage in November 2023. The action resulted in Singtel Optus subsidiaries, including Optus Mobile, paying more than $12 million in infringement notice penalties for breaches relating to emergency calls.