The Cisco Packet Voice Digital Signal Processor Modules (PVDMs) enable Cisco 4000 Series Integrated Services Routers (ISRs) to provide rich-media capabilities such as high-density voice connectivity, conferencing, transcoding, media optimization, transrating, and secure voice for Cisco Unified Communications solutions. These modules support unprecedented scale while allowing for a smaller solution footprint than ever before.
T1/E1 voice
One of the primary uses of PVDMs is to packetize digital voice into IP packets to enable time-division multiplexing (TDM) digital voice applications.
Conferencing
PVDM modules support ad hoc and meet-me conferencing with various codecs in conjunction with Cisco Unified Communications Manager and Cisco Unified Communications Manager Express.
Transrating
The PVDMs support transrating, in which the same codec is repacketized in order to connect dissimilar networks that have different codec packetization periods.
Voice-quality management
The PVDMs perform compression, voice-activity detection, jitter management, and echo cancellation. The echo cancellation offered in the PVDMs has a tail length of 128 milliseconds and complies with ITU-T G.168.
