The P-DRA function mainly uses databases. Subscribers are dynamically assigned to a PCRF. This assignment is called a binding. The binding exists as long as the subscriber has at least one policy Diameter session.
A high-level view of SBR Binding and Session databases consists of several pieces:
- There is one instance of the Binding database in the entire P-DRA network.
- There is one instance of the Session database per Policy DRA Mated Sites Place Association.
- Each binding record is associated with at least one Diameter session record. Binding records contain one Session Reference for each Diameter session that is associated with that binding.
- When a binding exists, there is at least one IMSI Anchor Key, Session, and Session Reference record.
- The IPv4, MISISDN, and IPv6 Alternate Keys are optional. They represent alternate ways, other than the IMSI, to identify a subscriber.
