"Don't buy IP just for dial tone and remember to include an IP audit before even commencing," he said.

Pattas cited Telstra's investment in CDMA as an example of a technology investment that became redundant in only three years.

"What I'm saying is don't put all your eggs in one basket; maybe you just need to install an IP-enabled switch," he added.

Not surprisingly, Ericsson is betting its future on mobility and the convergence of the laptop and mobile phone.

The company is currently in talks with all the major carriers to partner on the One Phone Solution it plans to launch in Australia next year. Rather than investing in infrastructure, the solution enables PABX access via the mobile phone.