Another technique to locate the interconnect FXO and FXS ports in close proximity to each other is to put a mixed-configuration (has both FXO and FXS ports) interconnect media gateway across the data network (thick gray line) in the "other" office, remote from its FacetPhone server.  The FacetPhone server must use a VPN tunnel to communicate with its remote media gateway. This configuration is functionally equivalent to the one in the previous diagram (page 5) where each office has a remote FXS interconnect media gateway located in the "other" office.