I am installing up new Tel & VM systems for small companies, doctor's offices, etc. A small system like a 4x4 configuration and a fax is a the size I am referring to.
The customers don't want to go to the expense of adding a dedicated line for remote access for maintenance, and neither do I (I'm just a little company, too).
I want to use a solution I have seen before- using an analog fax linein combination with a multi-selector switch (A-B-C) connected to the line. A would go to the fax, B would go to the phone system modem, and C to the voicemail system modem. Of course, a customer would have to turn the switch when access is needed, and turn it back to A when work is completed.
Is this a good solution? Is there a better solution, automatic or manual?

I have used that kind of set up for at least 10 years, it works fine. Just remember to tell the customer to throw the switch back where they want it when your done. They always forget.
mark

Sounds like money is the object here.

I would stick with the old standard toggle switch. Cheap and it works. I always mount mine at the backboard and Lable it according to where it goes. Then I always make sure I walk the customer through what it does and how it works.

Another way if I have an external modem, I hook it up to the line first and come out of it to the phone system. Then I just have them turn it on when I need to dial in, It will kill the connection to the system as soon as it answers.

Good luck!

Does that mean 2 external modems-one for the phone system and one for the voicemail system?

The easiest, but not the cheapest, solution would be a Stick or other line share device. You would just add ,#3#3 in your modem dialout string. Nothing for the customer to forget to turn on or off.

Plus, if they don't pay their bill, you can always disable their phones.

The Stick sounds like a good deal. Have you used these? I am wondering about reliability.

Yes, very reliable.

Command Communications makes some very good line share devices. Also, LSDI out of Canada has some good stuff. I have used both and with no problems.

These all sound like good prospects. I'll look into them. Thanks!