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.