It looks like you are the paging / sound guy and not the phone system installer?

I know i have heard in the past that a separate server was needed in order to page from a Cisco system ... that is why many locations with new Cisco systems still have the old phones sitting on the desk ... just so they can page.

If i were in your shoes i would throw it back on the installer of the phone system and let them figure it out.

You could always call Valcom or Bogen .. their support is very good .. there aren't many Cisco people here.