We have run into an interesting situation. We run our core application on an IBM RS6000 F80. We send files thru a Motorola UDS V.3229 modem to a remote vendor. Last week our program (modem?) no longer connects to the phone line. We get a message that the modem is unable to detect a answer tone. We have a backup site where all the same equipment works fine, we transported all the hardware to our main location and experience the same problem using the hardware that works great at the backup site. Our pbx vendor says there are no problems on their system, our phone company says there are not problems on the phone lines. Both vendors say the modem is bad, except it (and all the other hardware involved) works great from the backup site.
I am, of course, supposed to make it work. Not being a genius, I have turned to the site that I most respect for dispensing help.