Dsp Resources; Codecs; Restrictions For Transcoding And Mtp For The Cisco Vgd 1T3 Voice Gateway; Information About Transcoding And Mtp For The Cisco Vgd 1T3 Voice Gateway - Cisco VGD-1T3 Software Configuration Manual

Restrictions for Transcoding and MTP for the Cisco VGD 1T3 Voice Gateway

DSP Resources

The Cisco VGD 1T3 voice gateway uses PVDM2 modules to provide DSP resources for transcoding and
hardware MTP services. Use Cisco Unified Communications Manager 5.0 (formerly known as
Cisco CallManager 5.0) or later for transcoding and for MTP. You must have Cisco IOS
Release 12.4(20)YA or later.

Codecs

End-user devices must be equipped with one of the following codecs:
Codec
G.711 a-law, G.711 mu-law
G.729, G.729A, G.729B, G.729AB
Restrictions for Transcoding and MTP for the Cisco VGD 1T3
Voice Gateway
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Information About Transcoding and MTP for the Cisco VGD 1T3
Voice Gateway
To configure transcoding, you should understand the following concepts:
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Cisco VGD 1T3 Voice Gateway Software Configuration Guide
152
Using Cisco Unified Communications Manager to Configure Transcoding and Media Termination Point
DSP farm services communicate with Cisco Unified Communications Manager using Skinny Client
Control Protocol (SCCP); other protocols are not supported.
DSP farm services are not supported for Cisco Survivable Remote Site Telephony (SRST) or
Cisco Unified Communications Manager Express.
Hardware MTPs support only G.711 a-law and G.711 u-law. If you configure a profile as a hardware
MTP, and you want to change the codec to other than G.711, you must first remove the hardware
MTP by using the no maximum sessions hardware command.
Only one codec is supported for each MTP profile. To support multiple codecs, you must define a
separate MTP profile for each codec.
If an MTP call is received but MTP is not configured, transcoding is used if resources are available.
Dynamic conference and transcoding resource allocation is not supported.
Fax is not supported for transcoding.
DSP Farms, page 153
DSP Farm Profiles, page 153
Transcoding and MTP, page 153
Media Termination Point, page 154
Allocation of DSP Resources, page 154
Transcoding Session Capacities, page 155
Packetization Periods for Transcoding (ms)
10, 20, or 30
10, 20, 30, 40, 50, or 60