Cisco voice DSP info
- DSP resources available for transcoding and not used for voice termination are referred to as a DSP farm.
Conferencing and Transcoding Services Link to Cisco
Note: Different-generation PVDM types can exist on different voice cards within the same router, but not on the same voice card
With PVDM2, Cisco Integrated Services Routers and voice network modules provide both digital and analog voice connections and conferencing and transcoding services. In conjunction with host software, PVDM2 supports universal transcoding when needed. Universal transcoding allows transcoding from any supported codec to any other supported codec. As a general rule, the number of sessions needed for a universal transcoding channel is the sum of the session requirements for two separate voice channels, one running each of the configured codecs. For example, a channel running universal transcoding from a G.729a codec to iLBC would need the session capacity for a voice channel running the G.729a codec and MIPS (million instructions per second) for a voice channel running the iLBC codec.
- Table 1. Channel Density of Each PVDM2 Module
Name |
Max G.711 |
Max High-Complex Codecs |
Max Medium-Complex Codecs |
PVDM2-8 |
8 |
4 |
4 |
PVDM2-16 |
16 |
6 |
8 |
PVDM2-32 |
32 |
12 |
16 |
PVDM2-48 |
48 |
18 |
24 |
PVDM2-64 |
64 |
24 |
32 |
- The number of channels in PVDM2 product numbers and descriptions is the maximum channel density with the G.711 codec.
- Table 2. Codec Support on the PVDM2 Module
Name |
High-Complexity Codecs |
Medium-Complexity Codecs |
PVDM2 Module |
G.723.1, G.728, G.729, G.729b, iLBC, and Modem Relay |
G.7112, g.729a, G.729ab, G.726, G.722, and Fax Relay |
Table 5-1 PVDM3 Support
Router |
Motherboard |
Number of Supported PVDM3 |
Cisco 2921, 2951 |
Default |
2 |
Cisco 2921, 2951 |
Default |
3 |
Cisco 3925 |
SPE 100 |
4 |
Cisco 3945 |
SPE 150 |
4 |
Cisco 3925E |
SPE 200 |
3 |
Cisco 3945E |
SPE 250 |
3 |