If anybody can help with this, it will be appreciated. Until last weekend, we were receiving inbound faxes on our UCM6202 IP PBX without issue - they would forward off to the correct e-mail, no problem. Now, however, they suddenly stopped working and fax machines are not able to establish succesful connections and transmit. I have called our fax number and receive a fax tone. I can see inbound faxes are being correctly sent to our T.38 Fax extension, but the calls are always exactly 23 seconds long (I’m assuming this is where the timeout puts it), and the sender receives an error that the fax couldn’t be sent. I have tried restarting the UCM, and creating a new fax extension, but neither of those things helped.
Everything is coming in over a SIP trunk and was working fine for over a year before this.
Anybody have any insight, or the ability to point me to where I might be able to find more detailed logs of the inbound fax process?