Cisco PVDM4-128= 128-Channel DSP Voice Network Module - Black

 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.

Universal transcoding

 In conjunction with Cisco IOS Software, the PVDMs support universal transcoding, which allows conversion from any supported codec to any other supported codec.

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.

Energy savings

 The motherboard PVDMs (PVDM4s) offer multiple power-saving modes, including a power-saver mode when the module is not in use. In power-saver mode, each PVDM4 can save up to 5 watts of power.