Delayed Media Update Enabled

When you enable the SIP delayed media update feature, the Oracle® Enterprise Session Border Controller:

• Delays changing the active media flow CAM entry for a new offer if a previous offer and answer have been received for the same media flows; it encodes new SDP information in an outgoing offer, but does not change the CAM entry until the answer is received
• Delays changing the active media flow CAM entry even when the new offer is for a new session
• Supports media release when performing delayed media update changes
• Offers per-realm configuration

This section describes how the delayed media update feature works for hairpinned call flows and for an SDP offer arriving for installed flows.

• Hairpinned call flows—In this type of call flow, the application server (AS) sends an INVITE back to the Oracle® Enterprise Session Border Controller and that INVITE needs to be forwarded to another user (user B). When it receives the offer in this INVITE and delayed media update is disabled, the Oracle® Enterprise Session Border Controller determines that the call is hairpinned and deletes the CAM entry for the flow for user A, who has sent the initial INVITE. The Oracle® Enterprise Session Border Controller deletes the CAM entry for the flow from the AS to user A.

  With delayed media update enabled, the CAM entry for the flow from the AS to user A is not deleted. Instead, the Oracle® Enterprise Session Border Controller waits until it has an answer from user B, and then performs the necessary updates and deletions.

• SDP offer for installed media flows—With delayed media update enabled, if it has received an offer and answer and a new offer arrives for the same flow, the Oracle® Enterprise Session Border Controller delays updating the CAM entries until an answer is received for the new offer.