Cannot send faxes

[Vince Cannizzaro]

Hi,

I've been investigatiing an issue where users in a department are only able to send faxes 10% of the time.  The fax machine on the receiving party's end will answer but after sending 1 page the call disconnects and the machine tries to resend.  Eventually the fax transmission fails.

The setup is via an ATA 186 configured in CUCM 6.1.5.  I tried scaling the speed down to 14,400 and even 9600 on the fax/printer and configured the switchport as an access port.  I also connected the ATA to a different switchport on another switch.

Next, I tried another printer on the same floor and the same thing happened ruling our the machine.  I changed the ATA and it made no difference.  I also brought the original ATA back to my office and it faxed out to the same numbers without issue.

The T1 channels aren't filling up either and receiving faxes is no problem

Another test I did was plug the printer/fax into a dedicated phone line used for SRST purposes.  The printer faxed without any problems.  This leads me to wonder if it could be the router?  That seems to be the last common denominator.  It's configured with MGCP.

Has anyone had similar issues in the past?

Thank you for your time and help,

Vince

[Craig Cooper]

Hi Vince,

I'd suggest lowering the input gain on the voice port for the PRI, maybe to -3dB, and re-testing (requires a shut/no shut, so would have to be done after hours).   Another possibility is that there's a packet being dropped somewhere, in which case I'd first try turning off ECT, or disabling Super G3, on the fax... if that's even possible.

Kind regards,

Craig

[Christopher Graham]

check for slips/errors on the PRI (show controllers t1).  If you see slips, verify that you have the following command:

network-clock-select 1 t1 x/x/x <--controller for the PRI

[Vince Cannizzaro]

Thank you Craig and Christopher for replying back, I appreciate it.  I will give these a try and

see where it leads.

Thank you for the suggestions,

Vince