This document provides a sample configuration for the second-generation 1- and 2-port T1/E1 multiflex trunk (MFT)
voice/WAN interface cards (multiflex VWICs), which support data and voice applications in Cisco multiservice
routers. The multiflex VWIC combines WAN interface card (WIC) and voice interface card (VIC) functionality to
provide the following improvements:

Support for both T1 and E1--T1/E1 MFT VWIC2 cards provide additional flexibility in configuring the MFT
VWIC2 cards by supporting T1, fractional T1, E1, and fractional E1 for both voice and WAN applications.
Drop and insert capability on all versions--All MFT VWIC2 modules now include the drop and insert
multiplexing capability, which eliminates external third party CSU/DSUs and drop and insert multiplexers.
Enhanced clocking capabilities--The 2-port MFT VWIC2s can enable each port to be clocked from
independent clock sources for data applications. This independent clocking capability is not supported for
voice applications and not supported with the AIM-ATM-VOICE-30 module.
Dedicated echo cancellation option--MFT VWIC2s have an onboard slot for a multiflex trunk dedicated echo
cancellation module (EC-MFT-32 and EC-MFT-64), offering an enhanced echo cancellation capability for
demanding network conditions. For more information about this feature, refer to the “

Configuring Hardware

Echo Cancellation

” chapter in the

Voice Port Configuration Guide

Prerequisites

Requirements

Before attempting this configuration, please ensure that you meet the following prerequisites:

Cisco IOS Image -- To run these features on T1/E1 interfaces, you must install an IP Plus or IP Voice
image (minimum) of Cisco IOS Release 12.3(14)T or a later release.
VWIC Support -- The multiflex VWIC cards are supported on Cisco 2600XM series, Cisco 2691, Cisco 2800
series, Cisco 3700 series, and Cisco 3800 series routers when installed on the network modules listed in

Components Used

. The multiflex VWIC cards can also be installed in any VIC slot on the router.

Independent Clocking Mode -- The independent clocking mode is supported only on these modules:

VWIC2-1MFT-G703
VWIC2-2MFT-G703
VWIC2-2MFT-T1/E1
VWIC2-1MFT-T1/E1

To enable independent clocking mode, use the keyword

independent in the clock source command. The

independent keyword expands on the clock source internal and clock source line commands to

specify that the port can operate on an independent clocking domain. Prior to the addition of the

independentkeyword, port 0 was the default primary clock source, and port 1 was the default secondary clock

source and is loop-timed. With independent clocking enabled, this dependency no longer exists, so the

independent keyword means that both ports can be independently clocked.

When independent clocking is configured, the controller will support only one channel group and no voice applications. If more than one
channel group is configured, the following error message occurs:

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