Security concerns are holding back the takeup in IP telephony as it is considered another gateway into the corporate network for hackers.

Voice over IP (VoIP) is seen by many as approaching mass market adoption but Bert Whyte, CEO of said it will cost more than expected to install IP telephony as security of the infrastructure has to be taken into account in the final bill.

"I don't see VoIP becoming prevalent in corporate networks as most see it as another vulnerability to be dealt with, and the security concerns will cost money," said Whyte.

Kip McClanahan, CEO of TippingPoint Technologies claimed VoIP is a security threat to current infrastructure and where it is being rolled-out companies are taking extra time by installing it on a region-by-region basis and only progressing when it is judged safe to do so.

"Customers are sometimes surprised about the threat but what they need to do is clean up the network and secure it before rolling out VoIP," said McClanahan.

John McHugh, general manager of HP's Procurve Networking division said the problems faced by VoIP echo those faced by wireless networks four years ago. He said there were so many ports that had to be open to ensure high voice quality and claimed anyone could walk into a building and unplug an IP phone, plug in their own computer and gain access to the internal network.

He argued for more aggressive authentication processes and hardware data modules in phones that identified it to the IP network.