Release includes Office Communications Server 2007, VoIP software, and Office Communicator 2007 and marks Microsoft's entry into enterprise telephony Microsoft will open up beta versions of its unified communications server and client software to the public for download on Monday, a senior company executive said Wednesday.The release includes Office Communications Server 2007, its VoIP server software, and Office Communicator 2007, an application for mobile devices, said Gurdeep Singh Pall, corporate vice president for Microsoft’s real-time collaboration product group.The server is Microsoft’s entry into the enterprise Internet telephony business, where it hopes to replace traditional PBX systems as well as displace IP PBX systems from vendors like Cisco and Avaya. Microsoft has made its software compatible with a range of hardware an enterprise may already be using, such as gateways, phones, and other servers, Pall said.Microsoft has tightly integrated the server with its Office 2007 productivity suite and Active Directory, enabling click-to-call features based on a person’s name in applications like Outlook e-mail. Also wrapped into Office Communications Server, as well as Office Communicator 2007, are instant-messaging and video conferencing functions.Pall said Microsoft is trying to drive down the per-user cost of telephony, which can range between $100 to $200 per user per year for maintenance alone for PBX systems, he said. About 60 percent of enterprises are still using PBX systems and haven’t changed to VoIP systems, Pall said. Technology Industry