-- extensions.conf ---
[globals]
[general]
[default]
exten => 3171444444,1,Goto(extensions,3171444444,1)

[extensions]
exten => 3171444444,1,Dial(SIP/1002)

[internal]
exten => _XXXX,1,Dial(SIP/${EXTEN});

[toll-access]
include => extensions
exten => _X.,1,Dial(SIP/${EXTEN}@3171444444)

[incoming]
exten => s,1,Dial(SIP/1002)


-- sip.conf ---

[general]
context=default
bindport=5060
bindaddr=0.0.0.0
svrloookup=yes


register => 3171444444@budgetphone.nl:xxxxx:3171444444@sip.budgetphone.nl/3171444444

[3171444444]
nat=no
type=friend
context=incoming
host=budgetphone.nl
fromuser=3171444444
fromdomain=budgetphone.nl
username=3171444444
insecure=very
;insecure=invite,port
secret=xxxxx
qualify=no
port=5060

[1000]
type=friend
context=toll-access
host=dynamic
callerid="First Extension" <1000>
canreinvite=no
disallow=all
allow=gsm
allow=ulaw
allow=alaw
qualify=no

[1002]
type=friend
context=toll-access
host=dynamic
callerid="Second Extension" <1002>
canreinvite=no
disallow=all
allow=gsm
allow=ulaw
allow=alaw
qualify=no



    -- Executing [0715211111@toll-access:1] Dial("SIP/1002-08768000", "SIP/0715211111@317171444444") in new stack
    -- Called 0715211111@317171444444
    -- Got SIP response 482 "Loop Detected" back from 172.19.3.1
    -- Now forwarding SIP/1002-08768000 to 'Local/0715211111@incoming' (thanks to SIP/317171444444-0876d000)
[Oct 23 20:36:39] NOTICE[8185]: chan_local.c:570 local_alloc: No such extension/context 0715211111@incoming creating local channel
[Oct 23 20:36:39] NOTICE[8185]: app_dial.c:503 wait_for_answer: Unable to create local channel for call forward to 'Local/0715211111@incoming' (cause = 0)
  == Everyone is busy/congested at this time (1:0/0/1)
  == Auto fallthrough, channel 'SIP/1002-08768000' status is 'CHANUNAVAIL'
[Oct 23 20:36:55] NOTICE[8185]: chan_sip.c:14706 handle_request_subscribe: Received SIP subscribe for peer without mailbox: 1002
[Oct 23 20:39:55] NOTICE[8185]: chan_sip.c:14706 handle_request_subscribe: Received SIP subscribe for peer without mailbox: 1002