Fax not being received, but receiving delivery confirmation

[MMstre]

I have a customer using fax over a SIP trunk, across CUBE.  Faxing are not being received and i believe its related to the fax machine, but need additional information.  The problem is intermittent, some faxes are received.  I tested a few faxes and my fax server reports success, but the customer end is not receiving them.

Topology is

SIP (PSTN) -> CUBE -> SIP -> CUCM8.5 -> STCAPP -> FXO on CUBE

Dial-peers are matching, g711u is being used, no transcoding.

calls complete to the fax.

Some SIP debugs are returning cause code 486 (busy).  this may actually be the case, during the debugs i did see other calls coming to this number.  But even after a few retries, my fax succeeds.

Any help or insight would be greatly appreciated.

Thanks,

Mike

[yuanwu]

Hi, Mike

Your issue sounds a bit complicated, and need more information to diagnose, please open a TAC ticket, thanks.

Rgds/Randy

[MMstre]

Strangely, rebooting the router seemed to help.

I am not sure why, but the customer tells me that after rebooting the router, a bunch of faxes spewed out of the fax machine, as if they were being queued, but the router does not queue faxes, and i am not sure why the machine would queue them and release them after rebooting the router...

This sounds as if it is a problem with the machine, not the router, but i am confused on what would cause this...

[yuanwu]

Hi, Michael

nice to hear the issue was fixed.

if you want to know the root cause, we have to collect the debug from GW when the issue can be recreated  and isolate the issue to the particular device where the problem existed.

Rgds/Randy