Here is an example configuration where obviously you should replace the 'yournumber' with your actual Kiwi VoIP number (e.g. 099749000) and 'yourpassword' with your Kiwi VoIP line password. NOTE: Kiwi VoIP use the STD code+number format for usernames e.g. 099749000 rather than the E164 version (6499749000) as some providers do.

sip.conf

[general]

registerattempts=0

registertimeout=20

; Register line should be somewhere inside your general section

register => yournumber:yourpassword@sip.kiwivoip.co.nz/yournumber

[Kiwi VoIP]

type=friend
username=yournumber
fromuser=yournumber
secret=yourpassword
host=sip.kiwivoip.co.nz
context=default ; or your own selected context if desired
dtmfmode=rfc2833
disallow=all
allow=ilbc
allow=gsm
allow=alaw
allow=ulaw
;allow=g729 ; only if you have licenses to use it
nat=yes
canreinvite=no
 insecure=very  ; use insecure=invite,port in later versions of Asterisk such as v1.4


extensions.conf

[default]

;receive incoming calls to a connected phone

exten => s,1,Dial(SIP/yournumber)

; outbound calls (outside of your own PBX)

 exten => _X.*,1,Dial(SIP/${EXTEN}@Kiwi VoIP)