Funny how they do not know. BTW, I did a install with the PAGING over lan valcom install once. One unit, hooked to the key or pbx is the master. The other one at the other side is the slave. I also had trouble, but mostly with obtaining the paging signal on from the nortel pbx to the valcom master. You have to look into the software and configure it there. Do you have the ability to allow one of us techs to remote into both units?