Asterisk’s sip.conf file, in /etc/asterisk, contains entries for each SIP endpoint or trunk that can communicate with the Asterisk SIP server agent. Each entry can have multiple allow and disallow keywords, which indicate what codecs are to be used for each peer. The following configuration sets up a group of LAN phones and a group of remote, WAN-connected phones:
[general]
disallow=all
allow=ulaw
allow=g279
allow=speex
[601]
; phone on same LAN as
callerid="Jegee" <601>
context=Cleveland
host=dynamic
type=friend
username=601
secret=browns
[502]
; phone in remote location, connected by WAN
disallow=all
allow=g729
callerid="Maddie" <502>
context=Maui
host=dynamic
type=friend
username=502
secret=aloha
