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Influence Traffic Routing

  • The SMF may control the data path of a PDU Session so that the PDU Session may simultaneously correspond to multiple N6 interfaces.
  • We have provided some smaple scripts under the free5gc-compose, you can test the content in this note with
    sudo docker run --rm --network <free5gc-nw-name> \
    -v "$(pwd):/mnt" -w /mnt curlimages/curl <script.sh>

Influence traffic routing by UDR

  • Traffic routing can be triggered by storing/updating/removing the information in UDR.

Example usage of traffic influence

  • In the free5gc-compose, we have a compose file for ulcl, with two default UPFs: I-UPF and PSA-UPF.

  • Suppose that we want to let mec traffic go through the I-UPF, others go through the PSA-UPF.

    Others (Default) MEC (after TI)

  • We could put the influence data to UDR, triggering traffic influence process and influence the traffic routing.

    • Sample traffic influence data: ti_data.json
      {
    "dnn": "internet",
    "snssai": {
        "sst": 1,
        "sd": "010203"
    },
    "interGroupId": "AnyUE",
    "trafficFilters": [
    {
        "flowId": 1,
        "flowDescriptions": [
            "permit out ip from <server-cidr> to 10.60.0.0/16"
        ]
    }
    ],
    "trafficRoutes": [
        {
            "dnai": "mec"
        }
    ]
}
    • Use curl to put the data to the UDR.
      curl -X PUT -H "Content-Type: application/json" --data @./ti_data.json \
    http://<udr-interface>:8000/nudr-dr/v1/application-data/influenceData/1
    • To check the created influence data, use the following command.
      curl -X GET -H "Content-Type: application/json" \
    http://<udr-interface>:8000/nudr-dr/v1/application-data/influenceData?dnns=internet
    • You can also remove the traffic influence data by the following command.
      curl -X DELETE -H "Content-Type: application/json" \
    http://<udr-interface>:8000/nudr-dr/v1/application-data/influenceData/1

Screenshots

  • We use this sample topology to show the example usage of traffic influence
  • Traffic routing before influence
    • ping 1.1.1.1 (UERANSIM <-> I-UPF <-> PSA-UPF <-> Server)
      ping-1111
    • ping remote server (UERANSIM <-> I-UPF <-> PSA-UPF <-> Server)
      ping-server
  • Traffic routing after influence
    • ping 1.1.1.1 (UERANSIM <-> I-UPF <-> PSA-UPF <-> Server)
      ping-1111-tied
    • ping remote server (UERANSIM <-> I-UPF <-> Server)
      ping-server-tied

Influence traffic routing by NEF

  • An Application Function (AF) may send requests to influence SMF routeing decisions for User Plane traffic of PDU Sessions.
  • The AF requests may influence UPF (re)selection and allow routing of user traffic to a local access (identified by a DNAI) to a Data Network.

AF requests targeting a group of UE

23502-figure-43621

TS 23.502 figure 4.3.6.2-1 Processing AF requests to influence traffic routing for Sessions not identified by an an UE address

  • Example usage in free5GC
    • AF send JSON data to NEF, e.g. af_ti_anyUE.json
      {
    "afServiceId": "Service1",
    "dnn": "internet",
    "snssai": {
        "sst": 1,
        "sd": "010203"
    },
    "anyUeInd": true,
    "notificationDestination": "http://af:8000/test123",
    "trafficFilters": [{
        "flowId": 1,
        "flowDescriptions": [
            "permit out ip from <server-cidr> to 10.60.0.0/16"
        ]
    }],
    "trafficRoutes": [
        {
            "dnai": "mec"
        }
    ]
}
    • Use curl to POST the data to NEF.
      curl -X POST -H "Content-Type: application/json" --data @./af_ti_anyUE.json \
    http://<nef-interface>:8000/3gpp-traffic-influence/v1/af001/subscriptions

AF requests targeting an individual UE

23502-figure-43641

TS 23.502 figure 4.3.6.4-1 Handling an AF request targeting an individual UE address to the relevant PCF

  • Example usage in free5GC

    • Provide PFDs in uerouting.yaml before SMF start up

      //...
pfdDataForApp: # PFDs for an Application
    - applicationId: app1 # Application identifier
        pfds: # PFDs for the Application
          - pfdID: pfd1 # PFD identifier
            flowDescriptions: 
              - permit out ip from <server-cidr> to 10.60.0.0/16

      • Packet Flow Description (PFD): A set of information enabling the detection of application traffic provided by a 3rd party service provider.

    • AF send JSON data to NEF, e.g. af_ti_singleUE.json

      {
    "afServiceId": "Service1",
    "AfAppId": "app1",
    "dnn": "internet",
    "snssai": {
        "sst": 1,
        "sd": "010203"
    },
    "ipv4Addr": "10.60.0.1",
    "notificationDestination": "http://af:8000/test123",
    "trafficRoutes": [{
        "dnai": "mec"
    }],
    "suppFeat": "01"
}

    • Use curl to POST the data to NEF.
      curl -X POST -H "Content-Type: application/json" --data @./af_ti_singleUE.json \
    http://<nef-interface>:8000/3gpp-traffic-influence/v1/af001/subscriptions