Asterisk log, taken from console :-
Asterisk Ready.
-- Accepting UNAUTHENTICATED call from 213.166.5.129:
> requested format = alaw,
> requested prefs = (ilbc|gsm|alaw|ulaw),
> actual format = ilbc,
> host prefs = (ilbc|gsm|alaw|ulaw),
> priority = mine
-- Executing Answer("IAX2/213.166.5.129:4569-1", "") in new stack
== Auto fallthrough, channel 'IAX2/213.166.5.129:4569-1' status is 'UNKNOWN'
-- Hungup 'IAX2/213.166.5.129:4569-1'
-- Accepting UNAUTHENTICATED call from 213.166.5.129:
> requested format = alaw,
> requested prefs = (ilbc|gsm|alaw|ulaw),
> actual format = ilbc,
> host prefs = (ilbc|gsm|alaw|ulaw),
> priority = mine
-- Executing Answer("IAX2/213.166.5.129:4569-2", "") in new stack
== Auto fallthrough, channel 'IAX2/213.166.5.129:4569-2' status is 'UNKNOWN'
-- Hungup 'IAX2/213.166.5.129:4569-2'
-- Accepting UNAUTHENTICATED call from 213.166.5.129:
> requested format = alaw,
> requested prefs = (ilbc|gsm|alaw|ulaw),
> actual format = ilbc,
> host prefs = (ilbc|gsm|alaw|ulaw),
> priority = mine
-- Executing Answer("IAX2/213.166.5.129:4569-3", "") in new stack
== Auto fallthrough, channel 'IAX2/213.166.5.129:4569-3' status is 'UNKNOWN'
-- Hungup 'IAX2/213.166.5.129:4569-3'
iax.conf section :-
[44numberprovided]
type=user
disallow=all
context=incomingexample
allow=ilbc
allow=gsm
allow=alaw
allow=ulaw
extensions.conf
[incomingexample]
exten => 44numberprovided,1,Dial(Sip/matt)
have also tried the following for extensions.conf
[incomingexample]
exten => 44numberprovided,1,Answer()
exten => 44numberprovided,1,Dial(200)
with the same result