The RCC scenario is a lightweight telephone integration scenario that provides Office Communicator 2007 R2 users the ability to integrate their PBX phone with the ease of use of their other business applications, such as Outlook. It is not necessary to migrate the existing PBX system to a VoIP-based IP telephony solution to enable these scenarios. This chapter provides information on the functionalities of RCC, background information on how the scenario works, the infrastructure that must be set up, and what must be configured on Office Communications Server 2007 R2 to implement the RCC scenario.