Enhanced SIP Port Mapping
This section explains how to configure SIP port mapping feature to support:
- Anonymous requests from endpoints
- Cases where endpoints dynamically change transport protocols between UDP and TCP
Anonymous Requests
If a SIP endpoint sends an INVITE message with a From header that is anonymous, the Oracle Communications Session Border Controller can find the registration cache entry by using the Contact and Via headers. In cases such as instant messaging (IM), where there is no Contact header, the Oracle Communications Session Border Controller can use the Via header.
The Oracle Communications Session Border Controller’s checks whether the reg-via-key option is configured for the access-side SIP interface where a REGISTER is received. If the option is enabled, the Oracle Communications Session Border Controller makes the via-key by adding the IP address from the Via header to the firewall address (if there is a firewall present between the Oracle Communications Session Border Controller and the endpoint).
When an INVITE arrives at a SIP interface where this option is enabled, the Oracle Communications Session Border Controller determines whether the From header is anonymous or not. If it is anonymous, then the Oracle Communications Session Border Controlleruses the Via-key to find the registration entry.