To be phased in over the next two years, the new network, covering 43 offices across Australia, will save A$40,000 in data communication costs alone.

With credit union offices located on remote Defence bases, ADCU head of technology Mark Favretti said the goal was to find a feature-rich solution that didn't break the bank.

"At the same time we wanted to use the upgraded network to carry voice traffic, doing away with our existing separate PSTN service, and take advantage of the many benefits offered by IP telephony," he said.

ADCU's last network upgrade was in 1997 and Favretti said it had certainly reached the end of its shelf life.

He said the co-operative selected Nortel for the project because security was an important factor and the vendor also has a relationship with ADCU's other service providers TransAction Solutions and Telstra.