C.2 ISRP example

24.3123GPPAccess Network Discovery and Selection Function (ANDSF) Management Object (MO)Release 17TS

C.2.1 UE and network configuration

The operator’s policy aims at steering the traffic generated by the following applications on the UE:

– SKP is a VoIP mobile app pre-configured to "internet" APN;

– YTB is a video streaming mobile app pre-configured to "internet" APN. User can also access the service via browser at YTB.com (IPv4 address A.B.C.D);

– FBK is a social media mobile app pre-configured to "internet" APN. User can also access the service via browser at FBK.com (IPv4 address W.X.Y.Z);

– VoLTE is an IMS voice mobile app pre-configured to "IMS" APN; and

– all other traffic goes via "internet" APN.

100100 is the PLMN ID of the HPLMN. HPLMN has EPC-routed WiFi with SSID="WiFi_EPC_A".

100101 is the PLMN ID of the roaming VPLMN. VPLMN has EPC-routed WiFi with SSID="WiFi_EPC_B"and non-seamless wireless offload with SSID="WiFi_NSWO_B".

C.2.2 Operator’s policies

HPLMN configures the policy as follows:

Within HPLMN:

– MAPCON rule A1 to route IMS APN to cellular only (WiFi restricted), rule priority = 30;

– MAPCON rule A2 to route internet APN to cellular with higher priority and to EPC-routed WiFi with lower priority, rule priority = 30;

– ISRP rule IFOM_1 to route SKP and YTB traffic to EPC-routed WiFi only (cellular restricted) and any other WiFi with lower priority during peak hours (7AM to 7PM), rule priority = 1;

– ISRP rule IFOM_2 to route SKP and YTB traffic to EPC-routed WiFi with higher priority and to cellular with lower priority during all hours, rule priority = 10;

– ISRP rule IFOM_3 to route FBK traffic to EPC-routed WiFi with higher priority and to cellular with lower priority during peak hours within TAC A and TAC B, rule priority = 1;

– ISRP rule IFOM_4 to route FBK traffic to cellular with higher priority and to EPC-routed WiFi with lower priority in all hours and locations, rule priority = 10; and

– ISRP rule IFOM_5 to route all traffic to EPC-routed WiFi with higher priority and to cellular with lower priority in all hours and locations, rule priority = 20.

When roaming:

– MAPCON rule B1 to route IMS APN to cellular only (WiFi restricted), rule priority = 30; and

– MAPCON rule B2 to route internet APN to EPC-routed WiFi with higher priority and to cellular with lower priority, rule priority = 30.

VPLMN configures the policy as follows:

– MAPCON rule B1 to route IMS APN to cellular only (WiFi restricted), rule priority = 30;

– MAPCON rule B2 to route internet APN to EPC-routed WiFi with higher priority and to cellular with lower priority, rule priority = 30; and

– ISRP rule NSWO_1 to route internet APN to NSWO; rule priority = 20.

C.2.3 ANDSF MO configuration

Figure C.2.3.1 shows the ISRP in the ANDSF MO configured by the H-ANDSF. The ForFlowBased ISRP flow distribution rules are shown in figure C.2.3.2.

Figure C.2.3.1: ISRP configured by H-ANDSF

Figure C.2.3.2: ForFlowBased ISRP configured by H-ANDSF

Figure C.2.3.3 below shows the ISRP in the ANDSF MO configured by the V-ANDSF:

Figure C.2.3.3: ISRP configured by V-ANDSF

C.2.4 Usage scenarios

Scenario 1

UE is in HPLMN. The only valid ISRP rule is ISRP/Home, which is therefore the active rule. The UE routes the traffic according to the policy configured by HPLMN for usage within HPLMN as configured in the ISRP/Home ISRP rule.

Scenario 2

UE is in a V-PLMN. The V-PLMN does not have an ANDSF server or the UE cannot establish connectivity with the V-ANDSF. The ISRP/Home rule is not valid. The only valid ISRP rule is ISRP/Roaming, which is therefore the active rule. The UE routes the traffic according to the policy configured by HPLMN for usage when roaming as configured in the ISRP/Roaming rule.

Scenario 3

UE is in a V-PLMN. The UE successfully establishes connectivity with the V-ANDSF and gets the policy. The ISRP/Home rule is not valid. The valid ISRP rules are ISRP/Roaming and ISRP/Visiting. Since the rules provided by the V-ANDSF take precedence in roaming situations, the active rule is ISRP/Visiting. The UE routes the traffic according to the policy configured by V-PLMN for roaming users as configured in the ISRP/Visiting ISRP rule.