Section: 12.2.4 APN level load control 12.2.4.1 General
Content: APN level load control refers to advertising of the load information at APN level granularity and selection of the target node based on this information. It helps to achieve an evenly load balanced network at APN granularity by the use of the dynamic load information provided within the Load Control Information with the APN scope. Only a PGW may advertise APN level load information. APN level load control is an optional feature that may be supported when the following pre-condition is applicable. Pre-Condition: In the given network, when the ratio of the configured APN resource to the overall capacity of the PGW is not the same across all the PGWs in the network. NOTE: In other cases, e.g. when all the resources of the PGW are available for all the APNs served by that PGW, the node level load information is exactly the same as APN level load information, for each of its APNs, and hence performing node load control is sufficient. If APN load control is supported and activated at the PGW, the PGW should advertise the APN load information. If the APN level load control feature is supported at the node performing the PGW selection, i.e. an MME, S4-SGSN, ePDG, TWAN, the node shall utilize this information when selecting the PGW.