AppendicesInstallation Manual 151A5.3 FirewallsIt is generally preferable that a IP Gateway network installation be connected with the IPnetwork outside of any existing firewall installation. When for practical or policy reasons, aninstallation must be routed through a firewall some performance degradation may occur.In the above example, the KX-TDA0480 is routed through a firewall. The Router IP addressno longer serves as the KX-TDA0480’s Default Gateway IP address. Instead, the internal IPaddress of firewall becomes the Default Gateway IP address to be associated with the KX-TDA0480.Also, when installing the IP Gateway network within a firewall, voice and fax packets must berouted through specified firewall ports using the information in the following table.Item No. Type ofCommunicationPort No. TCP /UDPPriority ControlAssignment(Recommended)1 Q.931 1720 TCP Priority2 H.245 1721, 1722, 1723,1724TCP Priority3 RAS 1718, 1719 UDP Priority4 RTP / RTCP 5004 - 5011 UDP Top Priority5 Telnet, FTP 21, 23 TCP Normal6 ISDN Service 5003 UDP PriorityInternal IP addressnnn.nnn.nnn.nnnExternal IP addressnnn.nnn.nnn.nnnSwitch/HUBEthernetIP PBXRouterFire WallIP NetworkWorkgroup