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Implementing Echo Cancel on a Tandem Call with Positive Voice Detection
Introduction
The following procedure details the steps for attaching an Echo Canceller to a conference leg, and then recording the output.
Prerequisites
You must have a DSP chip configured with the Echo Cancel function. See Configuring Echo Cancel.
Guidelines
• The Echo Cancel function must be on the same DSP chip as the channel(s) to which you are connecting it.
• You must attach the Echo Canceller to the channel before you connect the channel to any other DSP receiver.
Procedure
1. Connect Channels using the Connect 0x0000 message.
2. Attach Echo Cancel receiver using the Resource Connect 0x0127 message.
AIBs
A: Span/Channel (channel to attach Echo Cancel function)
B: Slot (of DSP card).
If using an additional DSP receiver, it must be on the same card that has Echo Cancel. Otherwise, enter a wild card and the best available card will be used based on resources available.
Mandatory TLV
Resource Type = Echo Cancel (0x0108)
Optional TLVs (to override default card parameters)
0x0677 Echo Cancel G.176 Modem Answer Detection