How It Works

As part of the new DP chunk allocation to UPF, the following mechanism must be followed:

  1. Allocate a free DP chunk to the UPF.

  2. Clear the subscribers from the node manager to CDL to free subscriber sessions matching the following criteria:

    • Newly allocated DP chunk (ipv4-startrange / ipv6-startrange as the non-unique keys for freeing the sessions).

    • Sessions created before the current system time.

  3. Trigger N4 Association update with Route Deletion Request to all other UPFs serving the specific DNN, except for the UPF selected as part of the new chunk allocation.

    Note

    All these steps must be triggered in-parallel.

  4. During clear subscriber trigger, use the new correlation Id as CorrelationIdDpChunkAuditLocal (0xFF0D), which must be used as part of the metrics during session deletion.

  5. The DNN can be Resource Manager DNN /Incoming DNN.

Note

In a sunny day scenario, clear subscriber from the node manager to CDL should not match any sessions in CDL. Also, the N4 Association update with the Route Deletion request should not have any effect on the UPFs as they are not using this chunk or route.