Feature Description
The following are the details for the load control and the overload control features.
Load Control
The load control enables a GTPC entity, such as SGW or PGW, to send its load information to a GTPC peer, such as MME, ePDG, and TWAN. This information is used to balance the session load across all the nodes supporting the same function, such as SGW cluster, as per their effective loads. The load information reflects the operational status of the GTPC entity resources.
cnSGW-C load control behavior is as follows:
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Activate or deactivate the load control support in cnSGW-C, using the CLI.
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When the load control feature is activated, cnSGW-C signals its load control information to the MME for the following reasons:
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Optimum GW selection procedures
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Enhanced load balancing across cnSGW-C in the network
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The calculation of the load control information is based on the deployment scenarios.
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The applicable GTPC request or the response message contains piggybacked load control information.
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cnSGW-C includes only the single instance of LCI (Load Control Information) IE as per the SGW load control information. cnSGW-C sends the LCI IE received from the PGW to the MME, along with its LCI information.
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The frequency of load control information inclusion at SGW is based on the deployment scenario. The SGW ensures the propagation of the new or the updated load control information to the target receivers is within the acceptable delay. This acceptable delay helps in achieving the effective load balancing act in the network.
Overload Control
The overload control enables a GTPC entity to reduce gracefully its own incoming signaling load by instructing its GTPC peers to send the reduced traffic. The GTPC entity reaches overload, when it operates above the signaling capacity. This overload results in a diminished performance, resulting in to impacts on the incoming and the outgoing traffic handling. The GTPC node uses the load information to reduce, or throttle, or reduce and throttle, the amount of GTPC signaling traffic between these nodes.
cnSGW-C overload control behavior is as follows:
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Activate or deactivate overload control support in cnSGW-C using the CLI.
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When the overload control feature is activated, cnSGW-C signals its overload control information to the MME or the PGW. This helps in controlling the GTPC signaling traffic towards itself.
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SGW supports the handling of the overload control information in all the applicable messages.
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The applicable GTPC request or the response message contains piggybacked overload control information.
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cnSGW-C includes only the single instance of OCI (Overload Control Information) IE as per the SGW overload control information. cnSGW-C sends the OCI IE received from the PGW to the MME, along with its OCI information.
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The calculation of the overload control information is based on the deployment scenario.
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cnSGW-C rejects with the cause as GTPC entity congestion, when the SGW is in self-protection mode.
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SGW doesn't store the MME or the PGW overload control information.
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SGW doesn't perform throttling towards the MME and the PGW.
Note | The load control and the overload control are optional features. |
For more information, see GTPv2 Load/Overload Support chapter in the UCC 5G cnSGWc Configuration and Administration Guide.