The gateway and coordinator for all communication between system components. The IVRS includes an E1 interface which provides the system with PSTN connectivity. The call management features of the IVRS include allowing calls initiated from intercoms and help phones to be flexibly registered to operators and escalated to alternate routes when operators are unavailable.

An additional IVRS can be added to the system to provide a fault tolerant redundant configuration to ensure high availability. Other optional features included Audio Recording and support for call escalation to public telephony numbers.