Page 366 - Asterisk™: The Future of Telephony

with the tag “(channel).” If you define a channel parameter under the [general] section,
you do not need to define it in each channel; its value becomes the default. Keep in
mind that setting a parameter in the [general] section does not prevent you from setting
it differently for specific channels; it merely makes this setting the default. Also keep
in mind that not defining these parameters may, in some cases, cause a system default
to be used instead.

Here are the parameters that you can configure:
accountcode (channel)
The account code can be defined on a per-user basis. If defined, this account code
will be assigned to a call record whenever no specific user account code is set. The
accountcode name configured will be used as the filename.csv in
the /var/log/asterisk/cdr-csv/ directory to store Call Detail Records (CDRs) for the
user/peer/friend:

accountcode=iax-username
adsi (channel)
Support for ADSI (Analog Display Services Interface) can be enabled if you have
ADSI-compatible CPE equipment:
adsi=yes|no
allow and disallow (channel)
Specific codecs can be allowed or disallowed, limiting codec use to those preferred
by the system designer. allow and disallow can also be defined on a per-channel
basis. Keep in mind that allow statements in the [general] section will carry over
to each of the channels, unless you reset with a disallow=all. Codec negotiation
is attempted in the order in which the codecs are defined. Best practice suggests
that you define disallow=all, followed by explicit allow statements for each codec
you wish to use. If nothing is defined, allow=all is assumed:
disallow=all
allow=ulaw
allow=gsm
allow=ilbc
amaflags (channel)
Automatic Message Accounting (AMA) is defined in the Telcordia Family of Docu-
ments listed under FR-AMA-1. These documents specify standard mechanisms for
generation and transmission of CDRs. You can specify one of four AMA flags to
apply to all IAX connections:
amaflags=default|omit|billing|documentation
authdebug (global)
You can minimize the amount of authorization debugging by disabling it with
authdebug=no. Authorization debugging is enabled by default if not explicitly
disabled:

338 | Appendix A: VoIP Channels