[general]
context=internal                ; Default context for incoming calls
allowoverlap=no                ; Disable overlap dialing support. (Default is yes)
udpbindaddr=0.0.0.0            ; IP address to bind UDP listen socket to (0.0.0.0 binds to all)
bindport=5060
bindaddr=0.0.0.0
tcpenable=yes                  ; Enable server for incoming TCP connections (default is no)
tcpbindaddr=0.0.0.0            ; IP address for TCP server to bind to (0.0.0.0 binds to all interfaces)
srvlookup=yes                  ; Enable DNS SRV lookups on outbound calls
notifyhold = yes               ; Notify subscriptions on HOLD state (default: no)
localnet=10.0.0.0/255.255.255.0
externip=xx.xxx.xxx.xxx
nat=yes

[1555]                         ; A locally attached SIP extension
type=friend
callerid=1555
canreinvite=no
dtmfmode=rfc2833
mailbox=1555
disallow=all
allow=ulaw
transport=udp
secret=1555
host=dynamic
context=internal

[Lync_Trunk]                   ; Our Lync trunk
type=friend
port=5068                      ; This is the default Lync Server TCP listening port
host=xx.xxx.xxx             ; This should be the IP address of your Lync Server
dtmfmode=rfc2833
context=from-lync
qualify=yes
transport=tcp,udp

[general]
static=yes
writeprotect=no

[globals]

[default]

[internal]
;dialling other extensions starting with 1 followed by three digits
exten=>_1XXX,1,Dial(SIP/${EXTEN},20)
exten=>_1XXX,n,hangup()

;dialling other extensions starting with 2 followed by three digits
exten=>_2XXX,1,Dial(SIP/Lync_Trunk/${EXTEN},20)
exten=>_2XXX,n,hangup()

[from-lync]

;dialling other extensions starting with 1 followed by three digits
exten=>_1XXX,1,Dial(SIP/${EXTEN},20)
exten=>_1XXX,n,hangup()