Cisco WRP400-G1 Administration Guide - Page 25

Configuring Your System for ITSP Interoperability Configuring NAT Mapping 2 STEP 6 Click Save Settings. NOTE You also need to configure the firewall settings on your router to allow SIP traffic. See "Firewalls and SIP," on page 26. Configuring NAT Mapping with STUN This option is considered a practice of last resort and should be used only if the other methods are unavailable. This option can be used if the following requirements are met: • You have a dynamically assigned external (public) IP address from your ISP. • You must have a computer running STUN server software. • The edge device uses an asymmetric NAT mechanism. If the WRP400 is the edge device, this requirement is not met. For more information, see "Determining Whether the Router Uses Symmetric or Asymmetric NAT," on page 25. • If the WRP400 is connected to an Ethernet switch, the switch must be configured to enable Spanning Tree Protocol and Port Fast on the port to which the WRP400 is connected. NOTE Use NAT mapping only if the ITSP network does not provide a Session Border Controller functionality. STEP 1 Start Internet Explorer, connect to the Configuration Utility, choose Voice > Admin Login. If prompted, enter the administrative login provided by the Service Provider. (The default username and password are both admin.) STEP 2 Under the Voice menu, click SIP. STEP 3 In the NAT Support Parameters section, enter the following settings: • Handle VIA received: yes • Handle VIA rport: yes Cisco Small Business WRP400 Administration Guide 23