OTTAWA — At least three Canadian military bases, including the navy's main West Coast operations hub, were hit with serious communications failures as Telus Corp. struggled to switch the Defence Department telecom network to their service, The Canadian Press has learned.

In fact, defence officials acknowledge there were two outages at Canadian Forces Base Esquimalt on the same day in July 2008, service interruptions that forced shore-based commanders to fall back on satellite phones to communicate with ships at sea.

The other outages that summer, which occurred within a few weeks of each other, took place at CFS Aldergrove, B.C., and CFB Winnipeg, the home of Canada's 1st Air Division command.

The Defence Department had previously acknowledged those service interruptions, but only recently confirmed what defence sources describe as the far more serious incident at Esquimalt.

The outage was important enough for the then-commander of Canada's Pacific fleet to write a letter of complaint to the officer in charge of the Global Defence Network Services contract in Ottawa, a defence source said.

A spokeswoman for National Defence downplayed July 16, 2008, incidents.

"Part of the communication at the base was lost, but ship-to-shore would have worked via SATCOM," said Louise Marin in an email.

The Defence Department denied interview requests about the problems, but responded with a serious of bullet-point questions and answers.

Marin said officials blamed the Esquimalt outage on a Telus technician's "human error," which caused a build-up and overload of information, something that eventually crashed the system.

She said additional measures were taken and the problem has not repeated itself.

A spokesman for Telus declined comment and referred questions to National Defence.

The $213-million contract to manage telephone, wireless, data, video and IP (Internet Protocol) services for the Defence Department has been glitch-plagued and controversial almost from the moment it was signed in 2007.

One aspect of the deal is currently before the federal cabinet, which has been asked to referee a dispute between Telus and Bell Canada (TSX: BCE), the company that previously provided the service.

Sources in the defence community said there have been other significant problems, including concern that Telus technicians who responded to service calls did not have the proper security clearance.

National Defence acknowledged security issues have caused some disruptions and delays, but said if a contract employee showed up without clearance they were turned away.

"During the transition from Bell to Telus, some technicians showed up who did not have the right clearance and could not be allowed on the premises without an escort, which caused some delays," Marin wrote.

"All technicians working on the secret network had the appropriate clearance, otherwise the work was postponed."

When the five-year contract was signed in June, 2007, Telus agreed to complete the transition from Bell within a year. But Marin acknowledged that some systems still remain on the old network, including alarm circuits.

"The Global Defence Network Services (GDNS) contract is in its fourth year of a five-year contract," Marin wrote.

"Migration of the telecom circuits (approximately 4,000 services) was completed in November 2009, with only the remaining alarm circuits (approximately 500 circuits) to be migrated. This migration (411 circuits done already) is proceeding according to plan and should be completed by December 2010."

Alarm circuits are the dedicated lines used to monitor intruder detection systems in places such as ammunition depots and weapons storage bays, according to defence insiders. They're similar to home security alarms.

"Where does DND get off justifying this?" asked Liberal defence critic Ujjal Dosanjh.

"It's an over-$200-million contract. It's a mess, the work has not been completed and there have been possible security lapses in the sense that people were not properly cleared ahead of time. This needs to be looked at."

Dosanjh wrote to Auditor General Sheila Fraser on Tuesday to ask for an investigation.

New Democrat defence critic Jack Harris called the incidents disturbing.

"The government doesn't seem to have a handle on this," he said. "It was up to the government to take action in the face of a series of failures to meet the contract deadline. Why didn't they do it?"

As a result of the delay, Telus has been required to pay Bell to maintain critical circuits that haven't migrated. But the two telecom giants have been locked in a bitter dispute over the rate -- something the federal cabinet is being asked to arbitrate.