Work with a Proxy Firewall 99SIPxNano IP-PBX Getting Started Guide B • Firewalls and NATWork with a Proxy FirewallFor phones to work in an environment with a proxy-based firewall, the firewall must have a SIP-specific proxyimplemented. Refer to the documentation provided by your firewall vendor for instructions on how to config-ure its SIP features.Configuring phones for a SIP firewall proxyFor phones to work with a SIP firewall proxy, you are likely to need to set the SIP_PROXY_SERVER parameterRoute all outbound SIP messages through proxy to the internal IP address of your SIP firewall proxy.Depending on the requirements of the SIP firewall proxy that you use, you may also need to configure yourphones by setting one or more of the following:• HTTP proxy host name and HTTP proxy port numberPHONESET_HTTP_PROXY_HOST and PHONESET_HTTP_PROXY_PORT• Host address outside NAT firewallPHONESET_EXTERNAL_IP_ADDRESS• Port for inbound SIP TCP messages and Port for inbound SIP UDP messagesSIP_TCP_PORT and SIP_UDP_PORT• Starting port for RTP/RTCP packetsPHONESET_RTP_PORT_STARTUsing HTTP proxy settingsPhones use the HTTP protocol to download software upgrades and application .jar files. If these HTTP trans-actions have destinations on a remote server and must go through a proxied firewall, you may need to set valuesfor the HTTP proxy host name and HTTP proxy port number to allow the phones to originate the HTTPtransactions. Examples for these parameters follow.PHONESET_HTTP_PROXY_HOST: HTTP proxy host name: httpproxy.Patton.comPHONESET_HTTP_PROXY_PORT: HTTP proxy port number: 8080
