We have a client that's currently set up with 6 pots lines... 4 go into the fxo holes on the Adtran NV 6k and two go to nearby fax machines. They don't want to pay for six lines. They'd like to go down to two lines for just the fax machines and use the fxo ports for outgoing only. Currently the fxo ports are used for outgoing calls when the internet is down and we use a trunk-number/ring-group to forward incoming calls to the secretary phones in their main office.
But what they'd like to do is disable all incoming calls on the fxos and put their fax machine on a Y-splitter.
[fax machine] -----------------------\
[adtran](fxo) --------------------------\----------- {pstn}
So outgoing calls would still use the fxo during failover mode (this part is easy and already works) and have the fax answer the incoming calls. This seems completely impossible because the Adtran seems to pick up incoming calls even if you delete the trunk-number. We experimented with a buttphone and found that the adtran sends a busy tone, though I could hear the installer over the line. The tone lasted some 12 seconds and went away... but clearly the fax won't work like this.
Due to building wiring, there's no obvious way to put the fax machine right inline with the fxo line, which is the only way I can think to get this to work unless there's some setting I'm missing. (Spent a lot of time in the AOS command reference, and I'm not hopeful there's a solution for this.)
