AAPT has seen revenues from dial-up internet services more than double in the last financial year, growing from $19 to $39 million.
But voice revenues fell $62 million to $282 million over the same period, which contributed heavily to a reduction in inter-carrier costs of $87 million.
"Revenue is coming off in voice which means we buy less off Telstra," AAPT chief Paul Broad said.
"That obviously [impacts our negotiation position with carriers] and obviously Telstra would like us to grow our business with them."
AAPT recently inked a new wholesale agreement with Telstra. It spends about $500 million a year on Telstra services.
But Broad was not too hung up on the voice reduction. "You can get lost in consumer but it's the wholesale and business divisions where we make all our money and where we're good at," he said.
There were signs the consumer business revenues were growing on the back of AAPT's unlimited products.
These included an ADSL2+ service with unlimited off-peak downloads between 2am and 8am.
The telco had previously indicated the off-peak hours could be extended due to the success of the product.
Broad said the unlimited plans had broadened AAPT's customer demographics, attracting more "younger people" in their 20s to sign-up.
AAPT recorded a 10 percent increase in earnings before interest, taxes, depreciation and amortization (EBITDA) of $22 million for the fourth quarter.
Full year figures were slightly less than the previous one, down four percent to $72 million.
The telco had managed to claw back operating expenses in part by outsourcing to a call centre in Manila, "significant data storage cost reductions, IT support contract renegotiation and bringing network maintenance in-house".