PVDM belongs to the Cisco Interface Cards. SO, what is the PVDM?
Overview of PVDM
A Packet Voice Digital Signal Processor Module (PVDM) is a hardware module that provides digital-signal-processor (DSP) resources to the system. A PVDM module can be populated with one or more DSPs. The DSP resources on a PVDM provide collaboration services including voice sessions, transcoding sessions, conference sessions, and video.
The DSP chip plays a crucial role in the Cisco Unified Communications system. It comes in several form factors, from soldered on to the main board of the Cisco Unified IP phone or gateway, to the modular packet voice DSP module (PVDM). The PVDM can have multiple DSPs on the module.
In other word, DSP and PVDM make Cisco ISRs series connect the IP Phones. That means, we can buy one ISR, one PVDM and one UC license to realize Voice communication.
PVDM2 vs. PVDM3
Now, Cisco routers support PVDM2, PVDM3 and PVDM4 modules but this article only discusses the difference between PVDM2 and PVDM3. The PVDM3 modules provide higher density (up to four times higher) than the PVDM2s.
This chart shows the comparison between PVDM2 and PVDM3.
|
PVDM |
PVDM2 |
PVDM3 |
|
Supported Platform |
Cisco 2800, 3800, 2900, 3900 Series ISRs |
Cisco 2900, 3900 Series ISRs |
|
Models |
PVDM2-8 PVDM2-16 PVDM2-32 PVDM2-48 PVDM2-64* |
PVDM3-16 PVDM3-32 PVDM3-64 PVDM3-128 PVDM3-192 PVDM3-256* |
|
Capabilities |
Voice/fax |
Voice/Video (no Cisco Fax Relay) |
|
Resource Sharing |
Per-module and per-chassis sharing |
DSP resources in motherboard slots shared across the chassis back plane |
|
Coexistence |
Can coexist on the Cisco 2900 and 3900 Series ISR platforms but PVDM2 cannot be installed directly on the motherboard |
|
*Number in the model name identifies the number of supported G.711 channels.
This Table shows us the models of PVDM3 and PVDM2 Modules.
|
Name |
Description |
|
16-channel high-density voice and video DSP module |
|
|
32-channel high-density voice and video DSP module |
|
|
64-channel high-density voice and video DSP module |
|
|
128-channel high-density voice and video DSP module |
|
|
192-channel high-density voice and video DSP module |
|
|
256-channel high-density voice and video DSP module |
|
|
8-channel packet fax/voice DSP module |
|
|
16-channel packet fax/voice DSP module |
|
|
32-channel packet fax/voice DSP module |
|
|
48-channel packet fax/voice DSP module |
|
|
64-channel packet fax/voice DSP module |
How to install the PVDM2 in the Cisco 2900 and 3900 ISRs?
In Cisco 2900 and 3900 series, PVDM3 modules are easy to install without adapter, while the PVDM2 modules need adapter. There is a video about how to install PVDM2 module from Cisco website. We can download the Video here: PVDM_Adapter.swf
It means that PVDM2 can be installed in the 2900 and 3900 ISRs with adapter. The adapter model is the PVDM2-ADPTR, the PVDM2 Adapter for PVDM Slot for 2901, 2911, 2921, 2951, 3925, 3925E, 3945 and 3945E.