Telecom XT's 12-hour service failure, which affected about 100,000 customers south of Taupo yesterday, raises serious issues about the design of the network, a telecommunications watchdog says.
The XT service began having problems about 5am yesterday, which caused a loss of mobile service including voice, SMS and mobile broadband.
The service was not fully restored until 5pm.
Telecom spokesman Mark Watts said a technology fault, affecting a network component, occurred in a Christchurch-based "node" which controlled the Taupo-south part of the network.
Whether or not that was adequate for a $600 million service which promoted 97% coverage around New Zealand, he declined to debate.
"It's complex. I'm not going to debate network infrastructure with you tonight."
Telecom had made a substantial investment in the XT network and the "right level of investment" had been made in it.
"Networks from time-to-time experience problems."
Telecommunications Users Association of New Zealand chairman Chris O'Connell said the failure raised issues about its design and whether it was a one-off problem.
Normally, networks were designed with back-ups and alternative pathways for such situations.
But yesterday's failure made people question whether that was in place, he said.
The failure sounded like it was the result of an attempt to rectify an outage about three weeks ago, Mr O'Connell said.
Mr Watts said the company would be doing "110%" to ensure its XT mobile customers did not face another outage.
"We'll be keeping a close watch . . . to ensure it stays working," he said last night.
"We'll be reflecting very carefully and will be doing 110%, our damnedest to ensure it doesn't [happen again]."
Yesterday, customers were urged to use landlines if they needed to call emergency services, because not all XT devices were "smart phones" which automatically roamed to find another network in those instances, he said.
Telecom retail chief executive Alan Gourdie said services were progressively restored throughout the afternoon.
"We apologise and deeply regret any inconvenience to our customers."
Telecom did not expect customers to pay for services they had not received, Mr Gourdie said.
He said customers would receive "some form of appropriate compensation", NZPA reported.
Otago Chamber of Commerce chief executive John Christie said the network failure was inconvenient.
Many people relied on the network for everyday business.
The financial impact on businesses varied, but the main impact was the inability to communicate quickly and reliably.
