Asterisk Sip Trunks settings

Peer Context: withtel
host=sip.withtel.com.au
directmedia=no
type=peer
username= <username>
fromuser= <username>
secret= <your-password>
qualify=5000
nat=yes
disallow=all
allow=gsm
allow=alaw
allow=ulaw
dtmfmode=rfc2833
sendrpid=pai

USER Context: <username>
type=user
host=dynamic
secret= <your-password>
dtmfmode=rfc2833
disallow=all
allow=gsm
allow=alaw
allow=ulaw
context=from-trunk
directmedia=no
nat=yes
qualify=no
directmedia=no
trustrpid=yes
insecure=port

CREDITS
John Roberts john.roberts@withtel.com.au - Marketing Director.
David Freeman david.freeman@withtel.com.au - Programing