Digium, Inc.
Page 41
Chapter 3: Configuration
Configuring Card Features
You will need to modify the chan_dahdi.conf file which is located in the
/etc/asterisk directory in order to configure the essential features of your
card. This file is the configuration layer between DAHDI and Asterisk.
Switchtype:
national:
National ISDN 2 (default)
dms100:
Nortel DMS100
4ess: AT&T
4ESS
5ess:
Lucent 5ESS
euroisdn: EuroISDN
ni1:
Old National ISDN 1
qsig:
Q.SIG
Echocancel:
Echo Cancellation is enabled in chan_dahdi.conf by preceding the
channel variable with a variable called echocancel and its length in taps (#
of milliseconds multiplied by 8); for example:
echocancel = yes
channel => 1-23
By default, and when setting to "yes," echo cancellation is enabled and set
to 16 ms (128 taps). Echo cancellation is explicitly disabled by setting:
echocancel = no
Digium does not recommend that users set echo cancellation to "no."
Users of open source Asterisk-based echo cancelers also have the
following options:
echocancel = 128 (this sets 128 taps or 16ms)
