5.4 Data traffic routing of IP flows

24.3023GPPAccess to the 3GPP Evolved Packet Core (EPC) via non-3GPP access networksRelease 17Stage 3TS

5.4.1 General

In regards to the routing of IP flows, 3GPP TS 23.402 [6] defines the following UE capabilities: IFOM capability, inter-APN routing capability, NSWO capability and MAPCON capability. Any of these capabilities can be enabled and disabled via UE configuration means outside of the scope of this document. A capability that exists and has not been disabled is considered as supported. A capability that does not exist or the existing capability that has been disabled is considered as not supported.

A UE can have several sets of information about access technologies or access networks or both to assist in determining the data traffic routing of IP flows. These sets of information are:

– the Inter-APN Routing policies. The IARP can be statically provisioned in the UE. Additionally, the IARP can be provided by the H-ANDSF. The UE shall ignore the IARP received from the V-ANDSF;

– the Inter-System Routing policies. The ISRP can be statically provisioned in the UE or it can be provided by the H-ANDSF or the V-ANDSF or both;

– the Local Operating Environment Information. The Local Operating Environment Information can be optionally generated by the UE locally and the contents of Local Operating Environment Information is implementation dependant;

– user preference settings;

– the RAN assistance information (including OPI);

– the measurements corresponding to the thresholds in the RAN assistance information; and

– indications received from access stratum as described in clause 6.10.4.

This clause describes the relationship amongst these information sets and how they are used in order to route data traffic of IP flows. The Local Operating Environment Information does not apply to MAPCON rules in this version of the specification.

5.4.2 Access technology or access network selection

5.4.2.1 ANDSF rules control the WLAN access selection and traffic routing

This clause applies if the ANDSF rules control the WLAN access selection and traffic routing as described in clause 6.10.2.

When selecting the access technologies or access networks or both to route the data traffic of IP flows:

1) if a UE supporting IFOM or non-seamless WLAN offload is provided with user preferences and has IARP rule for NSWO, ISRP or Local Operating Environment Information or any combination of them, the user preference settings shall take precedence over IARP rule for NSWO (if present), ISRP (if present) and Local Operating Environment Information (if present).

2) if a UE supporting IFOM or non-seamless WLAN offload hasIARP rule for NSWO, ISRP and Local Operating Environment Information and no user preference settings and if based on the content of Local Operating Environment the UE decides that an access technology or access network or both do not meet implementation specific criteria for routing data traffic of a specific IP flow, the UE may exclude that access technology or access network or both when deciding on the routing of the data traffic for those IP flows.

3) if a UE supporting IFOM or non-seamless WLAN offload having Local Operating Environment Information but no available ISRP, IARP rule for NSWO and no user preference settings, the UE may evaluate the available access technologies or access networks against the Local Operating Environment Information.

When a UE supporting MAPCON selects the access technologies or access networks or both, to route the data traffic of a specific APN, the user preference settings shall take precedence over ISRP (if present) and IARP rule (if present).

The user preference settings shall take precedence over IARP (if present).

5.4.2.2 RAN rules control the WLAN access selection and traffic routing

Access technology or access network selection procedures in clause 6.10.4 apply if the RAN rules control the WLAN access selection and traffic routing as described in clause 6.10.2.