Page 387 - Asterisk™: The Future of Telephony

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 (both)
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
(default, omit, billing, or documentation) to apply to all SIP connections:
amaflags=documentation
callerid (both)
You can set a suggested Caller ID string for a user or peer with callerid. If you
define a Caller ID field for a user, any calls that come in on that channel will have
that Caller ID assigned to them, regardless of what the far end sends to you. If
Caller ID is defined for a peer, you are requesting that the far end use that to identify
you (keep in mind, however, that you have no way to ensure that it will do so). If
you want incoming callers to be able to define their own Caller IDs (i.e., for guests),
make sure you do not set the callerid field:
callerid=John Smith <(800) 555-1234>
callgroup and pickupgroup (both)
You can use the callgroup parameter to assign a channel definition to one or more
groups, and you can use the pickupgroup option in conjunction with this parameter
to allow a ringing phone to be answered from another extension. The
pickupgroup option is used to control which callgroups a channel may pick up—a
channel is given authority to answer another ringing channel if it is assigned to the
same pickupgroup as the ringing channel’s callgroup. By default, remote ringing
extensions can be answered with *8 (this is configurable in the features.conf file):
callgroup=1,3-5
pickupgroup=1,3-5
callingpres (both)
Sets Caller ID presentation for this user/peer. This setting takes one of the following
options:
allowed_not_screened
Presentation allowed, not screened
allowed_passed_screen
Presentation allowed, passed screen

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