The telco's general manager of network and technology, David Yuille, told iTnews the upgrade capped an 18-month redesign of the network prompted by its acquisition of Powertel.
That acquisition left AAPT with two separate networks, each at different points in their lifecycles.
The response was to discontinue both and build a brand new IP core network.
"It's an engineer's dream to sit down and design a network from scratch," Yuille said.
"It's a brand new network - we didn't incorporate any of the legacy network. There's virtually no equipment re-use."
Yuille said the IP core network upgrade will enable AAPT to guarantee the performance of symmetric mid-band Ethernet services. These provide uplink and downlink speeds up to 40Mbps.
The telco has provided mid-band Ethernet for up to three years, using equipment from Hatteras Networks.
"Before [the upgrade], Ethernet performance and bandwidth was good but not guaranteed," he said.
Mid-Band Ethernet services allows carriers to deliver the metro Ethernet services over copper. They are seen as a mid-point between ADSL2+ and fibre Ethernet services.
ISPs such as Internode are backing SHDSL technology as an alternative to addressing the business market beyond ADSL2+.
Yuille said he believed mid-band Ethernet was the right path for AAPT because it did not introduce the translation challenges at the network layer that SHDSL does.
Separately, AAPT also unveiled a 10Gb Ethernet offering yesterday.
"We're seeing this massive shift to carrier-grade Ethernet and this new network is designed to enable [us to facilitate that for customers]," he said.
"10GbE [10Gb Ethernet] is just the first product out of the gate. A Layer 2/3 VPN service is due out in the July timeframe and we also plan to build on the coverage of our mid-band Ethernet service."
The core IP network equipment for the upgrade was supplied by Cisco, while the edge upgrade used equipment from Alcatel-Lucent.
Yuille said the edge upgrades would enable AAPT to streamline provisioning and fault resolution processes for customers.
"We've got a focus on shortening provisioning times and resolving faults in a quicker fashion," he said.
"The technology from Alcatel-Lucent lends itself to that well."
AAPT's new Ethernet suite will be available to Wholesale customers mid-May and for businesses mid-July.
The network completion and product launch is part of an "aggressive" customer acquisition strategy targeting medium to large corporates, AAPT chief Paul Broad said.
"We're poised to roll out a new suite of unique Ethernet products, providing customers with scalable data solutions at very competitive prices - in some cases, up to 50 per cent less than other providers," he said.