Mark Barrett, a network engineer with the organisation's information services division told a Sydney conference today his group would bring the solution provided by vendor Avaya to another 10-12 sites before the end of the year.
The AFP was applying a "cookie cutter" approach to the project, with each site receiving a standardised large or small install depending on its size, he said.
The number of staff covered by the rollout was not disclosed, but the migration is believed to be one of the nation's largest.
According to Barrett, the project wasn't just about reducing the cost of telephone calls, a commonly touted benefit of moving from a traditional analogue system to all-digital IP telephony.
"What was important was what we could do in terms of new functionality," he said, pointing out the organisation already had a comprehensive analogue telephony system in place.
Four key benefits would be realised from the project, he said.
Firstly, utilising the AFP's extensive data network for voice meant telephony services could be provided in previously problematic areas.
For example, Barrett said, the local families of overseas AFP operatives in between 30 and 40 countries could now call their loved ones over the network for the cost of a local call.
Secondly, the ability for staff to gain access to their personal phone system through any given handset had proven a boon as certain AFP employees frequently moved between projects.
Staff could now log themselves into any phone, eliminating the need to call a helpdesk to get their calls re-routed to a new location.
Thirdly, Barrett said, the AFP had started to link its PC standard operating environment to the IP telephony system, with "easy wins" including the ability for staff to dial phone numbers straight from their Outlook contacts.
Lastly, the AFP has started to deploy additional functionality into the handsets such as the ability to access the organisation's corporate directory.
While Barrett praised the Avaya technology generally, he said he found the vendor's implementation of the Simple Network Management Protocol used to monitor network-attached devices not as robust as he would have liked.
"It's a little problematic ... sometimes it times out and that sort of stuff," he said, noting the AFP had generated a customised workaround for the problem.
Barrett's team also has other matters on its hands than just the ongoing telephony rollout.
The AFP is trialling the integration of video conferencing into the new system, building on the strengths of an existing, but less flexible, solution in use for the past several years.
The organisation also wants to build more applications into the Avaya handsets and simplify its database structure for keeping track of employee's extension numbers.