[Customer_End_Trunk]
type=endpoint
transport=transport-udp
context=outbound
tone_zone=au
dtmf_mode=auto
disallow=all
allow=alaw
allow=ulaw
allow=g729
t38_udptl=yes
t38_udptl_ec=fec
t38_udptl_maxdatagram=400
set_var=FAXOPT(gateway)=yes,20
send_rpid=no
trust_id_inbound=yes
rtp_timeout=60
rtp_timeout_hold=120
timers=no
aors=Customer_End_Trunk
force_rport=yes    ;It's a good idea to read the configuration help for each
direct_media=no    ;of these options.
identify_by=ip

[Customer_End_Trunk]
type=aor
contact=sip:x.x.x.x:5060
qualify_frequency=5

[Customer_End_Trunk]
type=identify
endpoint=Customer_End_Trunk
match=x.x.x.x

[Supplier_End_Trunk]
type=endpoint
transport=transport-udp
context=inbound
tone_zone=au
disallow=all
allow=alaw
allow=ulaw
allow=g729
aors=Supplier_End_Trunk
send_pai=yes
dtmf_mode=auto
force_rport=yes    ;It's a good idea to read the configuration help for each
direct_media=no    ;of these options.
rtp_timeout=60
rtp_timeout_hold=120
timers=no
identify_by=ip
trust_id_outbound=yes ; This will set Privacy and PAI header appropriately

[Supplier_End_Trunk]
type=aor
contact=sip:y.y.y.y:5060
qualify_frequency=5


[Supplier_End_Trunk]
type=identify
endpoint=Supplier_End_Trunk
match=y.y.y.y