Allocation Of Dsp Resources Within The Dsp Farm; Transcoding Session Capacities - Cisco VGD-1T3 Software Configuration Manual

Using Cisco Unified Communications Manager to Configure Transcoding and Media Termination Point
If you previously allocated DSP resources to voice termination and you now try to configure a DSP farm,
you might find that insufficient DSP resources are available. Conversely, if you previously allocated DSP
resources to a DSP farm and you now try to configure a trunk group, you might find that insufficient DSP
resources are available.
If your requested configuration is rejected, you have two options:
•
•

Allocation of DSP Resources Within the DSP Farm

You should know the following about your system:
•
•
DSP resources can reside in packet-voice DSP modules (PVDM2s) installed in voice network modules
or directly in the network module. Cisco VGD 1T3 voice gateway routers have onboard DSP resources
located on PVDM2s installed directly on the motherboard. Your router supports up to six voice network
modules.

Transcoding Session Capacities

Each DSP is individually configurable to support transcoding and standard voice termination. The total
number of transcoding and voice termination sessions is limited by the capacity of the entire system,
which includes the DSPs, hardware platform, physical voice interface, and Cisco Unified
Communications Manager.
Table 1
can handle, in theory. Actual capacity may be less based on the total system design.
Table 1 DSP Theoretical Session Capacities
Application
Transcoding
G.711 a-law/u-law <->
G.729a/G.729ab
G.711 a-law/u-law <->
G.729/G.729b
Voice Termination
G.711 a-law/u-law
G.726, G.729a, G.729ab
G.729, G.729b, G.723.1, G.728
Insert more DSPs on the voice network module (NM-HDV or NM-HDV2)
Allocate a different voice network module for either the DSP farm or the trunk group
Number of DSPs required to handle your anticipated number of conference calls and transcoding
sessions
Number of DSPs that your system can support
and Table 2 list the maximum number of conference calls and transcoding sessions that DSPs
2 PVDM2-64
64 sessions
48 sessions
128 sessions
64 sessions
48 sessions
Information About Transcoding and MTP for the Cisco VGD 1T3 Voice Gateway
3 PVDM2-64
96 sessions
72 sessions
192 sessions
96 sessions
72 sessions
Cisco VGD 1T3 Voice Gateway Software Configuration Guide
4 PVDM2-64
128 sessions
96 sessions
256 sessions
128 sessions
96 sessions
155