Managing the SIP Proxy

Note: If a client is using the proxy when the transparent proxy is turned on, the existing users might fail to use the transparent proxy until the Smoothwall Firewall is rebooted. This is due to the in-built connection tracking of the Smoothwall Firewall’s NAT.


  1. On the SERVICES menu, under the Proxies submenu, click SIP.
  2. To turn on the SIP proxy service, select the Enabled option.
  3. From the SIP client internal address and SIP client external address lists, choose the interface to listen for internal and external connections on.
  4. Choose the Logging level and the Maximum number of clients that can use the proxy.
  5. From the Diffserv mark for RTP packets list, choose the Diffserv mark to apply to SIP RTP packets.
  6. If you don't want to use the SIP proxy as a registrar but want to allow internal SIP devices to communicate properly with an external registrar, select the Transparent option.
  7. If you want to log individual calls, select the Log calls option.
  8. To implement the SIP proxy, click Save.