The subway office telephone system uses the MDS6800 multimedia dispatch communication system based on soft - switching technology. It supports virtualization and cloud deployment, and provides basic communication units, dedicated service units, network management service units, billing service units, as well as trunk gateways and integrated access gateways. It realizes internal calls within the rail transit operation, management, and maintenance departments, local and domestic and international long - distance calls, multi - party conference calls, special services, billing, and computer - based operator functions. The system uses a primary - standby redundant cluster working mode. Each functional unit can be deployed with primary - standby disaster - tolerance and cluster redundancy, and a fault - switching mechanism to ensure normal service operation.

The Jiaxun Feihong office telephone system can be built as an independent system, or it can be combined with the subway dedicated telephone system using the same system for both public and dedicated purposes.