Specifications

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Cisco IGX 8400 Series Provisioning Guide, Release 9.3.3 and Later Releases
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Chapter 7 Cisco IGX 8400 Series Voice Service
Voice Service Provisioning
Idle-Code Suppression
Idle-code suppression (ICS) detects the idle (on-hook) state of a video call, which uses an nx64 kbps
data connection, and suppresses packet transmission during an idle condition. The UVM or CVM
identifies the idle condition by detecting the repetition of idle codes. IGX switch software enables or
disables the ICS feature dynamically.
Tip To enable ICS on a data channel, enter the switch software cnfdch command.
Channel Pass-Through
Channel pass-through allows two locally-connected voice card sets to support the maximum number of
channels on a T1, E1, or J1 line.
For example, only 16 channels can use G.728 (LDCELP) or G.729 CSACELP compression, but the total
number of channels allowable on a line may be greater than 16. With channel pass-through, the
remaining channels available on the line are passed from the first (or primary) voice card set to the
secondary card set for processing.
Channel pass-through is not necessary for G.729A CSACELP, and does not apply to channels that use
PCM, or ADPCM.
Tip To enable channel pass-through on a line, enter the switch software cnflnpass command.
Time-Division Multiplexing Transport
Time-division multiplexing (TDM) transport is only supported on Model C CVM cards.
TDM transport allows you to bundle time slots to form a single, transparent connection through the
network. TDM transport supports the following features:
• Bundling of 1–31 time slots for rates ranging from 64 kbps to 1984 kbps
• 8/8 line coding
• Preservation of time slot alignment within frames
• Supports data channel bundling only
Voice Service Provisioning
This section provides information on how to provision voice services on an IGX node. Information in
this section applies to the UVM and CVM. For information on how to provision voice services using the
URM card, refer to Cisco IOS documentation supporting your Cisco IOS release (also see the
“Accessing User Documentation” section on page xii).
For more information on the UVM, CVM, and URM card sets, see the “Universal Voice Module” section
on page 2-36, the “Channelized Voice Module” section on page 2-44, and the “Universal Router
Module” section on page 2-84.