SIP Transport Selection

With this feature enabled, when the Oracle® Enterprise Session Border Controller forwards a message larger than the value specified in the maximum UDP length parameter, it attempts to open on outgoing TCP connection to do so. This connection might fail for a number of reasons; for example, an endpoint might not support UDP, or it might be behind a firewall. The UDP fallback option addresses this condition. If it is configured in SIP interfaces associated with an outgoing message and a TCP session cannot be established, the Oracle® Enterprise Session Border Controller falls back to UDP and transmits the message. When the option is not present, the Oracle® Enterprise Session Border Controller’s default behavior is to return the SIP status message 513 Message too Large.