Digium, Inc.
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Chapter 3: Configuration
channel = 3-4
Users of Digium's hardware echo cancellation module, the VPMADT032,
should set the echocancel option to "yes." The module will automatically
configure itself to run at full capacity, 1024 taps (128ms), on each
channel.
Users without the VPMADT032 using open source echo cancelers
included with DAHDI should configure echocancel to the values 128
(16ms) or 256 (32ms). Setting "yes" will default the option to 128 (16ms).
Users who have not purchased an Analog 410 Series card with the
hardware echo cancellation module are encouraged to take advantage of
Digium's High Performance Echo Canceler software. This commercially
licensed software, which is made available at no charge to in-warranty
Digium analog interface card customers, provide toll quality echo
cancellation, performed on the host CPU, at up to 1024 taps (128ms) per
channel. For further details about HPEC, please refer to the Digium
website here:
http://www.digium.com/en/products/software/hpec.php
When HPEC is enabled, users may set the value of the echocancel
parameter to any of the following values:
128 - 16ms
256 - 32ms
512 - 64ms
1024 - 128ms
Note: Higher values will result in dramatically increased CPU
consumption. In order to optimize system performance, users are
