Hi -

It sounds like you have fax modems connected to SLC ports.

On my system, we had problems connecting modems to SLC-16 ports.

We were instructed to add a 150 ohm resister on each side of the cable pair.

For us there was an issue with both the SLC card and the modem tring to control the current on the circuit.

The extra resistance solved the issue.

Good Luck,
Russ