Louisa Voice recently replaced a 9-phone Avaya Partner ACS PBX along with a commercial firewall . The left hand side of the picture shows the legacy Avaya PBX and commercial firewall. The right side illustrates the Louisa Voice integrated firewall and open source telephony server. The Louisa Voice server has a similar footprint to the commercial firewall and is much smaller than the Avaya PBX. The Louisa Voice solution can support ~25 VoIP phones. Hardware packaging has improved significantly in the last ~30 years when the Partner PBX first appeared in the marketplace!