Page 1447 - 5G Basics - Core Network Aspects

Signalling aspects 3

BNG 1 BNG 2 Controller

Fault occur

Fault report

Retrieve the backup BNG

User session activation inform
Enable user sessions

Advertises routes

Figure 8-4 – The fault protection procedure

Each BNG in the BNG pool monitors its status and detects its faults. It reports the fault information to the
controller as soon as possible when a fault occurs. The controller receives the fault report and retrieves the
backup BNG. It then informs the backup BNG to enable the user session information in the forwarding plane.
The backup BNG starts to work for these affected users, and advertises corresponding routes based on the
IP address section that allocated by the controller as described in Section 8.1

The fault BNG will synchronize its user session to the backup BNG. The synchronization is performed in a real-
time manner so it assures that the fault protection does not break the service of online users. More details
of the synchronization is described in Section 8.4.

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