Large companies are starting to turn towards managed services for IP telephony because many believe they don't have the skills or knowledge to do IP convergence themselves, according to an IDC study.

Around 15 percent of the enterprises questioned use managed services today, but 40 percent are considering it, said Pim Bilderbeek, IDC's consulting VP. "The way people buy is changing," he said. "There is a knowledge gap in what enterprises know about convergence. More than a third of them think they don't know enough about it."

He added that a third of large European enterprises have already converged their voice and data networks, and predicted that three-quarters will have it done by 2008. However, he said that most are still using cost savings as the main justification for convergence, rather than increased productivity or efficiency,

"Many have dated comms infrastructures from multiple sources," he said. "IP networks give the possibility for someone else to take that on, and it can reduce costs because you're not doing things you don't understand or do well.

"Cost savings are a very important aspect, along with mundane drivers such as today's equipment reaching end of life and needing to be replaced."

The report was sponsored by BT and Cisco, and involved 440 large organisations in nine European countries. Aaron McCormack, BT's VP of network platforms and propositions, said that its oddest finding was the number arguing against VoIP.

"Five percent of respondents think they will never move to IP telephony," he said. "Well, I don't know who they think they'll be buying boxes off in 2010, because no-one's making TDM switches now."