Page 1446 - 5G Basics - Core Network Aspects

3 Signalling aspects

8.5 Signalling for user traffic scheduling among BNGs

To realize fault protection and load balancing, the controller is recommended to forward the corresponding
user session information to the target BNG and inform the BNG to enable the user session information in its
forwarding plane, thus the BNG can take over the corresponding user traffic.

The controller collects the load information of each BNG of the BNG pool in the running phase as depicted in
Figure 8-1. It assigns the BNG with lower load to serve the new access users. This make the load of each BNG
in the BNG pool balanced.
The figure below illustrates the load balancing procedure of the BNG pool.

BNG 1 BNG 2 Controller

Collect load

Real-time load

Collect load
Real-time load
Select BNG to serve a group of
users according real-time load
Assign the serving BNG
Serving access users

Figure 8-3 – The load balancing procedure

Each BNG in the BNG pool periodically collects and reports the load information to the controller. The
controller gets and figures out load status of every member in BNG pool, decides which BNG to serve the
new coming users, and then configures it. In this way, each BNG serves a part of the overall users to realize
the traffic load balancing among all the members of the BNG pool. The controller is responsible for traffic
allocation among all BNGs in the BNG pool to realize load balancing.
When the controller receives a fault report as described in Section 8.3, it knows a fault occurred in one BNG,
and will select a normal operation BNG device from the BNG pool to take over the fault one.
The figure below illustrates the fault protection procedure of the BNG pool.

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