Despite building a working IP telephony system based on the open source Asterisk PABX, a Sydney marketing company recommends staying clear of the 'immature' technology for at least another year.

While planning a move into new offices, Clear Blue Day (CBD) investigated the costs for a new phone system and concluded VoIP was an option.

Managing director Peter Bray said he couldn't justify the cost of a Commander system which would have resulted in "paying for expensive handsets rather than functionality".

"The reason Commanders are so expensive is because of technology, but you can get that in software for free these days," Bray said. "Surely someone has something approaching commercial grade."

The company first evaluated Axon's software PABX, including a paid support contract.

"Even with a technical background it was still difficult to set-up," Bray said. "We paid for support, but e-mail requests were taking over a week and the responses weren't up to scratch. And you could not transfer an external call internally [so] what's the point of a PABX?"

Bray said the only other option was Asterisk, which can transfer calls, but the company's telephony woes were far from being resolved.

"We knew where we were going to move, so we called Telstra and People Telecom for line activation and we thought we had it organized well," he said. "When we moved in for some reason the phone lines weren't connected properly and we didn't have data or Internet connection."

Bray said "eventually" the company got the phone line connected via two DSL links for dedicated data and VoIP.

CBD's first experience with Asterisk was "really, really poor" quality of service, which was "worse than mobile".

This was hardly surprising given Asterisk was running on a notebook, but even after it was migrated to a dual Pentium server there was a latency problem.

"There were improvements but there was this lag issue where it would take 3 to 4 seconds for the other person to hear it," Bray said. "When we purchased the better G.729 codec we didn't have as many issues."

On the client, CBD is using the iBeam softphone from Counterpath giving the company end-to-end software telephony.

"It's good to put names to numbers and just double click someone and incoming calls match address book," Bray said, adding while the company has wireless to improve the voice quality it is not used.

Another stumbling block was number portability as Telstra would not port CBD's old number to VoIP service provider Engin directly.

"We need to keep our old phone number [so] we are forwarding our old phone number to Engin," he said. "The main problem is we couldn't port the phone number and the extra hop affects the quality."

On top of that, Bray said Engin drops out on average once a week, as does People Telecom's DSL connection.

Bray recommends waiting 12 months to deploy software-based VoIP until there are more consultants in the market and the price is "more realistic".

"VoIP is unbelievable and as soon as it matures land lines are gone," he said. "We have an in-house CRM and want to go end-to-end as much as possible."