Unable to send receive FAX

[Amit Mestri]

Hi All,

I have a problem in sending and receiving the fax. we are using CUCM version 10.5, whenever I try to send a fax it fails with no errors, no logs for the event in CUCM, if I make a call to the FAX number I can hear the fax tone and can see SIP invites.

Please Help to resolve this issue.

Thanks 

Amit

[hartgravesc1]

What are you using? An ATA or a VG?

[Amit Mestri]

We are using VG

[R0g22]

Add the complete call flow and the fax protocol in use. Do you have any logs ?

[Amit Mestri]

Hi Nipun,

thanks for taking time to look into this. below are the details and logs i extracted.

Just for your info, when I make calls to the fax number I can see hear the fax tone and the SIP invites for the call, however when sending a test fax I don't see any logs. 

Call Flow : PSTN --> voice Gateway ISR4331/K9 --> 4 fax port ---> printer/fax

voice service voip
no ip address trusted authenticate
fax protocol t38 version 0 ls-redundancy 0 hs-redundancy 0 fallback none
sip
bind control source-interface GigabitEthernet0/0/0
bind media source-interface GigabitEthernet0/0/0
options-ping 60

dial-peer voice 8751 pots
destination-pattern 8751
port 0/2/1
forward-digits all
!
dial-peer voice 8761 pots
destination-pattern 8761
port 0/2/2
forward-digits all
!
dial-peer voice 8741 pots
destination-pattern 8741
port 0/2/0
forward-digits all

[R0g22]

Which log file is for the fax ? Have your confirmed that your ITSP supports T.38 ?

[Amit Mestri]

Hi Nipun,

it was working before. so I am sure that our service provider support t.38

could you please let me know what all logs you need. I will get it.

Thanks,

[R0g22]

Enable the following -

debug ccsip message
debug ccsip error
debug voice ccapi inout
debug voip vtsp all
debug vpm signal
debug fax relay t30 all-level-1