sip.conf

[general]
directmedia=no
directrtpsetup=no
dtmfmode=rfc2833
context=my-context
allowsubscribe=yes
qualify=no
subscribecontext=BLF
disallow=all
allow=ulaw
allow=alaw
allow=gsm
localnet=192.168.0.0/255.255.255.0
localnet=192.168.1.0/255.255.255.0

[123]
secret=mypassword
host=dynamic
type=friend