Document ID: 10762
Contents
Introduction
Prerequisites
Requirements
Components Used
Conventions
CVM Support
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Related Information
Introduction
This document explains functional differences that exist between Models A, B, and C of the Channelized Voice Module (CVM) on an IGX switch.
Note: The functionality of CVM Models A, B, and C is controlled by firmware.
Prerequisites
Requirements
There are no specific requirements for this document.
Components Used
This document is not restricted to specific software and hardware versions.
Conventions
For more information on document conventions, refer to the Cisco Technical Tips Conventions.
CVM Support
CVM Model A supports Digital Signal level 0 (DS-0), DS-0A (sub-rate < 56 kbps), and super-rate (up to 8x64) connections, as well as Pulse Code Modulation (PCM) and Adaptive Differential PCM (ADPCM) voice type connections. Model A has an echo canceller option. The product number is IGX-CVM-DS0A.
CVM Model B supports DS-0 and super-rate (up to 8x64) connections in addition to PCM and ADPCM voice type connections. It does not support DS-0A (sub-rate < 56 kbps) connections. Model B has an echo canceller option. The product number is IGX-CVM.
CVM Model C supports DS-0 Time Division Multiplex (TDM) transport connections at Nx64 up to T1 or E1 bandwidth. This provides for transparent circuit emulation. For T1, full bandwidth can be utilized by adding connections in 8x64 bundles. For E1, time slot 0 is reserved for frame alignment, national, and international signaling bits. To utilize the remaining 31 time slots of E1 bandwidth, connections must be added in 8x64 bundles. Model C does not support DS-0A (sub-rate) or PCM and ADPCM voice type connections. It does not have an echo canceller option. The product number is IGX-CVM-TT.
This table provides a summary of the differences in functionality between CVM Models A, B, and C:
|
Feature |
CVM Model A (IGX-CVM-DS0A) |
CVM Model B (IGX-CVM) |
CVM Model C (IGX-CVM-TT) |
|---|---|---|---|
|
DS0 |
Yes |
Yes |
No |
|
DS0A |
Yes |
No |
No |
|
Super-rate |
Yes |
Yes |
No |
|
DS0 TDM |
No |
No |
Yes |
|
PCM |
Yes |
Yes |
No |
|
ADPCM |
Yes |
Yes |
No |
|
Echo Canceller Option |
Yes |
Yes |
No |
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| Network Infrastructure: WAN Routing and Switching |
Related Information
- Cisco WAN Switching Solutions - Cisco Documentation
- Guide to New Names and Colors for WAN Switching Products
- Software Center - WAN Switching Software
- Technical Support - Cisco Systems
| Updated: Apr 17, 2009 | Document ID: 10762 |