SIP Registration Event Package Support

Certain endpoints subscribe to the Registration Event Package, RFC 3680, which defines how SIP user agents can request and obtain notifications about registration events. Previously, the Oracle® Enterprise Session Border Controller passed the Subscribe and Notify messages of this package transparently, without modifying the XML bodies of either. However, in many cases the XML body can contain IP addresses, contact URIs, and expires times that the Oracle® Enterprise Session Border Controller needs to modify for proper operation. This new feature enables the Oracle® Enterprise Session Border Controller to modify correctly the XML body for the Registration Event Package.

In addition to resolving this type of issue, enabling registration event package support on your system provides the functions described below:

The Oracle® Enterprise Session Border Controller performs NAT on all contacts in the reginfo, regardless of their state.
The Oracle® Enterprise Session Border Controller performs NAT on the address of record (AoR) attribute of the Registration element when it matches an existing cache entry. When either the Contact-URI or the AoR does not match a cache entry and the host part of the URI is an IP address, the Oracle® Enterprise Session Border Controller will NAT the host part using the applicable SIP NAT configuration
Contacts are found in the XML URI element for the contact. But if there is no URI element, then the Oracle® Enterprise Session Border Controller uses the Contact element information for the contact.
If the expires attribute in the Contact element is a value other than zero, the Oracle® Enterprise Session Border Controller uses (inserts) the expires values from the registration cache.
This feature also introduces delayed deletion from the registry cache. When a 200 OK comes back in response to a REGISTER message and the 200 OK does not include all previously registered contacts, the missing contacts are deleted. If the global SIP configuration option contact_cache_linger=XX (where XX is the number of seconds to wait before deleting), then the contacts to be deleted remain for the specified number of seconds before they in fact are deleted.