Traffic Readdressing or Redirecting
Traffic Redirection is the process of redirecting uplink application traffic to a redirect destination. For example, redirect some HTTP flows to service provisioning page. The redirect destination is provided by the PCF or it is preconfigured in the SMF or in the UPF.
The traffic redirection enforcement is applicable for the SMF or in the UPF if the traffic that the UPF supports subjects to traffic redirection. The UPF reports to the SMF whether it supports traffic redirection enforcement in the UPF through the "UP-Function Features" IE.
To enforce the traffic redirection in the UPF, the SMF takes the following actions:
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Creates the necessary PDRs, if it does not exist, to represent the traffic redirection.
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Creates a FAR with:
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The "Redirect Information" IE, that includes the redirect destination, if the traffic needs redirection toward a redirect destination that is provided by the SMF. The redirect destination from the SMF prevails over a redirect destination that is preconfigured in the UPF.
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For HTTP traffic redirection, the Redirection Address Type is set to "URL" and the SMF sets the "Destination Interface" IE in the FAR to "Access" (to forward the HTTP Response message with a status-code indicating redirect). For other types of traffic redirection, the "Destination Interface" IE in the FAR is set to "Core".
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Associates the FAR to the above PDRs of the PFCP session.