16 CHAPTER 1: P RE-I NSTALLATION GUIDELINESConfigurationOverviewThe VCX IP Telephony Solution (referred to in this guide as the VCXsystem) merges telephony with networking by delivering businesstelephone service over a data network.VCX servers run the VCX operating system and host softwarecomponents such as the Call Processor, VCX applications (such as IPMessaging), and configuration databases. SIP-enabled endpoints includeVCX telephones and gateways which provide user access to the PublicSwitched Telephone Network (PSTN)VCX system components can be installed in different configurationsaccording to the features required and the number of subscribers thatmust be supported. The system configuration determines the tasks youmust perform to enable communication between components.Software Configurations describes the VCX software components.Hardware Configurations, describes the two basic VCX configurations,single-site and multi-site systems.