User manual

Release 2.2 Digium, Inc. Page 34
Chapter 3: Configuration
Configuring Card Features
Configure Zapata.conf, which is the layer between zaptel and Asterisk, to
configure the essential card features.
Switchtype:
national: National ISDN 2 (default)
dms100: Nortel DMS100
4ess: AT&T 4ESS
5ess: Lucent 5ESS
euroisdn: EuroISDN
ni1: Old National ISDN 1
Echocancel:
Echo Cancellation is enabled in zapata.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)
or
echocancel=256 (this sets 256 taps or 32ms)