Systems and methods by which voice/data communications may occur in multiple modes/protocols are disclosed. In particular, systems and methods are provided for multiple native mode/protocol voice and data transmissions and receptions with a computing system having a multi-bus structure, including, for example, a TDM bus and a packet bus, and multi-protocol framing engines. Such systems preferably include subsystem functions such as PBX, voice mail and other telephony functions, LAN hub and data router or switch functions. In preferred embodiments, a TDM bus and a packet bus are intelligently bridged and managed, thereby enabling such multiple mode/protocol voice and data transmissions to be intelligently managed and controlled with a single, integrated system. In particular, systems and methods for generating required telephony voltages directly on station cards, rather than on the basis of a large, central ringing or other power supply that supply such telephony voltages to each of the station cards, are disclosed. In accordance with the present invention, a plurality of station cards are provided in the telephony or communications system. One or more DC power supplies provide a source of DC voltage, such as 12 volts, to each of the station cards. The station cards are coupled to a processor of the system. The station cards may support a plurality of analog and/or digital telephony devices, such as telephones facsimile, voice mail, recording, speakerphone, conferencing or other type telephony devices.