"We wanted to eliminate call charges between our stores, and reduce long-distance call charges irrespective of the call location, and IP telephony was ultimately the best way to do that," Hore said.

"Should the data network go down for any reason, the phones switch back to the PSTN network, which gives us that extra layer of service resiliency."

Hore expects a 100 percent uptake of IP from the franchisees which currently lease telephone systems at a premium price.

He described the project as a massive undertaking, but said the only glitch so far was losing the rubber feet off some handsets.

Nortel Australia/New Zealand enterprise networks general manager Nick Avakian said the migration will be completed this month with the rollout to franchisees to start in the first week of June.