Hello,

Actually, when you buy PVDMs for a router, you will have a part number like this "PVDM2-16", this PVDM contains 1 DSP 16 channels each DSP (16x1= 16 Channels), this happens with PVDM2s because each DSP on those models contains 16 Channels (exception, the PVDM2-8 contains 1 DSP of 8 Channels).

Here is the Table:

PVDM2-8 8-Channel 1 DSP (TNETV2505GGW) Module

PVDM2-16 16-Channel 1 DSP (TNETV2510GGW) Module

PVDM2-32 32-Channel 2 DSP (TNETV2510GGW) Module

PVDM2-48 48-Channel 3 DSP (TNETV2510GGW) Module

PVDM2-64 64-Channel 4 DSP (TNETV2510GGW) Module

We have PVDM2-8, -16, -32, -48 & -64; you just need to do the math in order to know the amount of channels per DSP.

Packet Fax or Voice DSP Modules: http://cisco.com/en/US/partner/products/hw/modules/ps2797/products_installation_guide_chapter09186a008007c8ea.html#wp1033936

High-Density Packet Voice Digital Signal Processor Modules: http://cisco.com/en/US/partner/products/hw/modules/ps3115/products_data_sheet0900aecd8016e845.html

In regards to normal PVDMs:

PVDM-4 = 1DSP x 4CH/ DSP = 4 CH

PVDM-8 = 2DSP x 4CH/ DSP = 8 CH

PVDM-12 = 3DSP x 4CH/ DSP = 12 CH

PVDM-16 = 4DSP x 4CH/ DSP = 16 CH

PVDM-20= 5DSP x 4CH/ DSP = 20 CH

It is exactly the same math, but you have half the amount of channels per DSP.

By the way, the router allocates the DSP resources at boot up and if I remember properly, on PVDM2s, it won't allow you to add more Conf/Xcode sessions that the ones that are available.

You can issue the "show voice dsp" command in order to see the channels that are being used per DSP on PVDM2s, and check this link for DSP troubleshooting/information commands:

http://cisco.com/en/US/partner/products/hw/modules/ps2617/products_tech_note09186a008039c316.shtml