IBM has agreed to acquire WebDialogs, a provider of voice, video and web conferencing technology.

Big Blue already offers on-premise conferencing technology. The acquisition allows the firm to expand into on-demand web conferencing, which will be offered through Lotus Sametime.

The collaboration software supports a series of communications technologies, including instant messaging, email and telephony, and lets users route incoming phone calls to a nearby handset or voice mail.

IBM has partnered with Siemens for its unified communications technology, which allows users to keep their existing PBX phone systems while expanding into an IP-based messaging infrastructure.

Although VoIP and IP-based communications services typically offer large cost savings over the long term, many firms shy away from adopting the technology because it forces them to rip out and replace existing infrastructure.