Many US businesses are not adequately securing their VoIP systems, industry analysts warn.

In-Stat said that, as businesses extend IP telephony deployments beyond the local area network, many are not taking VoIP infrastructure security seriously enough.

"An In-Stat survey of US businesses found that no mechanisms for securing VoIP had more than 50 per cent penetration across all sizes of business," said In-Stat analyst Victoria Fodale.

"Proactive measures, including periodic security audits and pre-deployment assessments, had low percentages of penetration too, even among the larger organisations."

Recent research by In-Stat found that over 80 per cent of survey respondents have deployed some type of VoIP technology.

The analyst firm estimates that 168 million IP PBX lines will be shipped into business premises between 2007 and 2010.

Use of collaboration and conferencing products that use VoIP is increasing, according to the research.