We have a SIP trunk from a provider coming into a 4331 CUBE. It goes SIP to CUCM. Then we have VG204s off CUCM via SCCP. There is a fax machine on the VG204. All faxes fail. The disconnect cause is 16 - Normal. However the fax reports an error in transmission. Originally we had the CUBE set for T.38 version 3. I have backed it down to T.38 version since the client advised they only require G3. Still does not work. Here is the CUBE config:
voice service voip
mode border-element
allow-connections sip to sip
redirect ip2ip
fax protocol t38 version 0 ls-redundancy 0 hs-redundancy 0 fallback none
h323
sip
bind control source-interface GigabitEthernet0/0/0
bind media source-interface GigabitEthernet0/0/0
header-passing
error-passthru
registrar server expires max 600 min 60
asserted-id pai
no update-callerid
midcall-signaling passthru
privacy-policy passthru
g729 annexb-all
no call service stop
We are requiring MTP resources on all calls for the trunk so I have MTP resources registered off the CUBE.
Any thoughts as to what could be wrong?