OBi 110 and analog fax / modem passthrough

[chumley]

I have an OBi 110 running the latest firmware. Google Voice setup as SP1, and is used as my primary voice line. My house phones lines are connected to the Phone port. I also have a POTS line connected to the Line port. Pretty standard stuff so far.

I also have an analog modem and fax machine that are connected to the house phone lines. I need to be able to make outgoing calls with these devices via the POTS line. I tried dialing the **8 prefix to tell the OBi to route outgoing modem calls to the POTS line. This does cause the calls to go out via the POTS line, and the receiving modem does answer, but the modems cannot connect. If I force the baud rate to 300 then they can connect, but all higher baud rates fail. If I bypass the OBi by physically disconnecting the cords from the Phone and Line ports and coupling them directly together, then the modem can connect at 33,600 bps. This proves that the OBi is interfering with the outbound modem calls.

I contacted support and they told me that the OBi digitizes all outgoing calls, even when routing them to the Line port. I don't know why that would be necessary, but it would explain my experience as described above. Their only advice was to run a separate wire from the fax/modem device to the OBi, install a splitter on the OBi Line port, and connect the new wire to that splitter so that the fax/modem device is connected directly to the POTS line.

Running a new wire from my fax/modem location to the OBi location would be a hassle, so I'm hoping that there is some other solution. Any advice or info would be appreciated. Thanks!

[QBZappy]

Welcome,

Try prefixing with "#" instead of "**8". This is supposed to bypass the OBI.

[chumley]

Thanks, but unfortunately the prefix "#" does not work either. It does cause the call to be routed to the POTS line, but the modems still cannot connect. The only difference that I could see is that if I dial # and pause for 1-2 sec, then I get a dial tone. If I dial **8, I do not get a dial tone.

[Shale]

The telephone line running around your house may have two pairs. If so, perhaps you can connect the currently unused pair to both your incoming POTS line and your fax machine. Be careful to continue to keep the Phone port on your OBi110 isolated from the incoming POTS line (Line port on your OBi).

I was wondering if some audio gain settings or capacitance settings would improve things. Those are doubtful. Making the analog connection is going to be best for you, I think.