Relationship to Symmetric Latching

The current forced HNT symmetric latching feature lets the Oracle® Enterprise Session Border Controller assume devices are behind NATs, regardless of their signaled IP/SIP/SDP layer addresses. The Oracle® Enterprise Session Border Controller latches on any received RTP destined for the specific IP address/port of the Oracle® Enterprise Session Border Controller for the call, and uses the latched source address/port for the reverse flow destination information.

If both restricted latching and symmetric latching are enabled, the Oracle® Enterprise Session Border Controller only latches if the source matches the restriction, and the reverse flow will only go to the address/port latched to, and thus the reverse flow will only go to an address of the same restriction.

• Symmetric latching is enabled.

  If symmetric latching is enabled, the Oracle® Enterprise Session Border Controller sends the media in the opposite direction to the same IP and port, after it latches to the source address of the media packet.

• Symmetric latching is disabled.

  If symmetric latching is disabled, the Oracle® Enterprise Session Border Controller only latches the incoming source. The destination of the media in the reverse direction is controlled by the SDP address.