Section: 12.2.5.1 Definition 12.2.5.1.1 General description
Content: Within a message, one or multiple instances of the Load Control Information (LCI) IE may be included by the same GTP-C entity. When providing load control information in a message for the first time or subsequently, the GTP-C entity shall always include the full set of load control information, i.e. all the node level and APN Level applicable instances of the Load Control Information, even if only a subset of the load control information has changed. All the instances of the LCI IE provided by a given GTP-C entity in a message shall contain the same Load-Control-Sequence-Number. The Load Control Sequence Number shall be incremented whenever the load control information is changed (see clause 12.2.5.1.2.1). The receiver shall overwrite any stored load control information of a peer with the newly received load control information (via one or multiple instances) from the same peer node if the new load control information is more recent than the old information as indicated by the Load Control Sequence Number, e.g. if the receiver has stored 'X' instances of the load control information for a peer node, it overwrites those 'X' instances with the new set of 'Y' instances received in a message from the same peer node, where X, Y are any integer number. The receiver shall consider all the parameters received in the same instance of the LCI IE in conjunction while using this information for node selection. When more than one instance of the LCI IE is received, the receiver shall consider the parameters included in each instance independently, when using this information for node selection. The parameters are further defined in clauses 12.2.5.1.2 and 12.2.5.1.3. Load control information may be extended with new parameters in future versions of the specification. Any new parameter will have to be categorized as: - Non-critical optional parameters: the support of these parameters is not critical for the receiver. The receiver can successfully and correctly comprehend the load control information instance, containing one or more of these parameters, by using the other parameters and ignoring the non-critical optional parameter. - Critical optional parameters: the support of these parameters is critical for the receiver to correctly comprehend the instance of the load control information containing one or more of these parameters. The sender may include one or more non-critical optional parameters within any instance of the LCI IE without having the knowledge of the receiver's capability to support the same. However, the sender shall only include one or more critical optional parameter in any instance of the LCI IE towards a receiver if the corresponding receiver is known to support those parameters. The sender may be aware of this either via signalling methods or by configuration; (this will have to be defined when introducing any such new parameter in future). Each instance of the LCI IE shall be associated to the node identity (FQDN or IP address of the GW node received from the HSS or the DNS) of the serving SGW or PGW, i.e. the identity determined during the SGW or PGW selection. NOTE: The Node type is derived based on the instance number of the LCI IE.