Voice over Internet Protocol (VoIP) enables placing and receiving voice calls over the Internet Protocol (IP) network. The call might or might not traverse the Public Switched Telephone Network (PSTN). VoIP is different from Remote Call Control (RCC). RCC is related to controlling the Private Branch eXchange (PBX) phone from a computer running Office Communicator, whereas in VoIP the audio traffic is carried over the IP network. VoIP has the potential of eliminating the need for a PBX network, which most large organizations must deploy and maintain in addition to their IP network. Managing these two independent networks, each with its own idiosyncrasies, requires administrators with various backgrounds and skills.

VoIP technology promises to deliver many improvements, such as infrastructure and network consolidation, lower management and toll costs, and better interoperability between systems from different vendors. The VoIP functionality of Office Communications Server 2007 R2 can replace PBX functionality in many cases and interoperate with existing PBXs in other cases.

Microsoft’s VoIP offering, Office Communications Server 2007 R2, provides an integrated user experience where voice communication is integrated into the same applications used by information workers to communicate electronically, such as Microsoft Office 2007, Microsoft Office SharePoint 2007, and Exchange 2007 SP1. With Office Communications Server 2007 R2, voice becomes one of many communications modes—e-mail, instant messaging (IM), desktop sharing, Web conferencing, file transfer, video—that are accessible from a single consistent user interface (UI). This ease of use encourages user adoption of more advanced features such as call forwarding, call redirection, and multiparty calls.

Another important advantage is portability. With Office Communicator 2007 R2 installed on their laptops and an Edge Server deployed in their organizations’ peripheral networks, users have access to their work numbers from anywhere in the world where Internet connectivity is available. This is a powerful proposition given a global economy where more and more workers telecommute. Office Communications Server 2007 R2 makes it possible for information workers to free themselves from the constraints of the office or cubicle.

On the Companion Media

Links to information related to the topics in this chapter are provided on the companion media.