PTT quota exhaust Limited Pass

Quota Exhausted Limited pass is proposed as an alternative to the Quota Exhausted Buffer due to the practical issues of the latter in the high-speed network. Buffering requires packet buffering for large number of packets at the gateway. The large number of packets can result in risking to run out of memory affecting the bandwidth speed. So, Limited Pass is an alternate to the Buffer option. Limited Pass allows the traffic to pass through until the configured limit on the Quota-Exhaust scenarios.

Use the following CLI command to enable the feature:

configure 
   active-charging service service_name 
      credit-control 
         pending-traffic-treatment quota-exhausted limited-pass volumevolume 
         end 
Note

The above CLI is only applicable for the 5G UPF architecture.

After the Limited-Pass volume exhausts, the further packets drop until the quota allocation comes.

Limited Pass allows the traffic until the Limited-Pass volume exhausts. The Limited Pass counts and adjusts the usage in the respective charging-bucket against the "Quota" granted. If the "Quota" allocation is less than the actual usage, there’s immediate reporting toward OCS with the usage-report and asking for more quota allocation.

If the limited pass volume doesn’t exhaust before the OCS responds with denial of quota, there’s traffic blockage after the OCS response. Gateway reports the usage in SX_SESSION_REPORT_REQUEST.

If the limited pass volume exhausts before the OCS responds, then further incoming packets for the session drop until grant quota from OCS.

The default pending-traffic-treatment for quota-exhausted is drop. The default pending-traffic-treatment quota-exhausted command removes any Limited Pass Volume size configured.