The Cisco voice interface cards (VICs) are daughter cards that install into the network modules and provide the interface to the PSTN and to telephony equipment (PBX, key systems, fax machines, phones).
The VIC2-2BRI-NT/TE provides the ability to connect a PBX or PABX configured as user side directly to the router. It also provides phantom power to accommodate equipment that requires it.
for Cisco 2900 and 3900 Series Integrated Services Routers
The Cisco High-Density Packet Voice Digital Signal Processor Module (PVDM3) enables Cisco 2900 and 3900 Series Integrated Services Routers Generation 2 to provide rich-media capabilities such as high-density voice video connectivity, conferencing, transcoding, transrating, and secure voice in Cisco Unified Communications Solutions.
The PVDM3s are supported on all Cisco 2900 and 3900 Series platforms. The PVDM3 provides higher density and more processing power than the PVDM2, making the addition of rich-media applications possible. Enhanced DSP architecture accommodates an original packet-processing engine optimized for rich-media voice and video applications, while concurrently supporting the time-division multiplexing IP (TDM-IP) voice framework used by the PVDM2.