Derrick, we have a POTS line dedicated to this modem in addition to a DID number. I already expected that we might have issues with the DID number (and we did) when the customer switched service providers to a SIP-type PRI service. The dedicated POTS line is a real copper one, on a 5ESS that has worked fine for years. We don't have web access to this system yet. We are getting clean disconnect signalling, etc. on this line, so I really doubt this is due to an external issue. Normally in the past, a hard reboot would resolve this issue, and it still does for one programming session. The next and subsequent attempts definitely receive fax tones, which is a new condition. There's no audible handshaking going on prior to the call dropping.

We may end up connecting an external modem to the COM port since this system is very active and has many programming requests weekly. Another option we're looking into is attaching a de-commissioned PC to the system with remote access into it. That would be the best idea since we wouldn't need to drag a laptop in during service visits, not to mention being able to do local backups, etc.

Ed Vaughn, MBSWWYPBX