atcomsystems.ca/forum Forums TDM Business Telephone Systems Avaya - Lucent Telephones & Systems Merlin 410 phones

I looked at the one I have briefly and it appears that there is a separate line cord connection for the fax and the BIS34D phone part. I think if they are connected with separate wiring, the phone and fax can be used simultaneously. There was a BTMI in the box with the system, so maybe that's how they had it connected.