The Network Address Translation (NAT) feature helps in the translation between internal private IP addresses and external public IP addresses. NAT also hides the original IP address of the host, which adds security. In addition, NAT helps to preserve the public IP addresses of an organization. The purpose of this document is to explain how to configure NAT on the SPA8000 phone adapter.
Step 1. Log into the web configuration utility as an administrator and choose Advanced > Voice > L1-L8. The Line page opens:
Step 2. From the Line Enable drop down list choose yes to enable the line for NAT setting configurations.
Step 3. Choose yes from NAT Mapping Enable drop-down list to make use of externally mapped IP addresses and SIP/RTP ports in SIP messages. The default value is No.
Step 4. Choose yes from NAT Keep Alive Enable drop-down list to save the configured NAT settings keep alive message. The keep alive message is a message delivered from a device that prevents the link between two communicating devices to be broken. The default value is no.
Step 5. In the NAT Keep Alive Msg field, enter the keep alive message that should be sent periodically to maintain the current NAT mapping. If the value for this field is $NOTIFY, a notify message is sent. If the value is $REGISTER, a register message without contact is sent. The default value is $NOTIFY.
Step 6. In the NAT Keep Alive Dest field, enter the destination that should receive the NAT keep alive messages. If the value is $PROXY, then the NAT keep alive messages are sent to the current proxy server or the outbound proxy server. The default value is $PROXY.
Step 7. Click Submit All Changes to save the settings.