Specifications

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Cisco IGX 8400 Series Provisioning Guide, Release 9.3.3 and Later Releases
OL-1166-04
Chapter 2 Cisco IGX 8400 Series Cards
Channelized Voice Module
• Accommodation for some signaling conversions through setting, inversion, and clearing of AB or
ABAB bits (T1) or ABCD bits (E1and T1 through ESF).
• Support for high-speed modem and fax circuits.
• Support for CAS through transport of signaling transitions across the network
For more information on voice technology specifications, see the “Voice Circuit Support” section on
page A-15.
Note The CVM does not support LDCELP or CSACELP compression and cannot terminate a connection from
a UVM if the connection uses LDCELP or CSACELP.
Voice frequency compression ratios can be determined through selection of a kbps rate for the voice
channel. For example, a 64 kbps voice channel does not compress voice traffic. A 32 kbps voice channel
compresses voice traffic at 2:1. See Table 2-30, “Cisco IGX 8400 Series Voice Service” (Chapter 7),
and the Cisco WAN Switching Command Reference for more information.
Table 2-29 Connections Supported on the CVM
Connection Type
Switch Software
Parameter Voice Coding Type Description
Voice p PCM Carries 64 kbps PCM voice with support for A-law or
mu-law encoding and conversion, gain adjustment, and
signaling.
Voice v PCM Carries voice with VAD.
Data t — Carries 64 kbps clear channel data traffic.
Vo i ce a 16 z
c16z
ADPCM Carries 16 kbps ADPCM voice. The “z” in the connection’s
switch software parameter directs the node to avoid routing
a16z and c16z connections across ZCS-configured trunks.
Note These connections do not ensure ones-density.
Vo i ce a 16
c16
ADPCM Carries 16 kbps ADPCM voice. These connections can be
routed over ZCS-configured trunks, and ensure ones-density.
A loss in voice quality results from ensuring ones-density.
Note These connections use a nonstandard form of voice
compression.
Voice+data a32d
c32d
Carries compressed fax. The c32d connection type provides
compression with VAD.
Note The c32d connection type only provides bandwidth
savings from VAD when the line is being used for
voice traffic.
Voice, data,
voice+data
a32
a24
ADPCM Carries 32 or 24 kbps ADPCM voice or data traffic.
Vo i ce c 32
c24
ADPCM with
VA D
Carries 32 or 24 kbps ADPCM voice traffic with VAD.