DSCP Markings for 4G Collapsed Datapath Calls
For collapsed Datapath calls:
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On Sxa leg, DSCP marking is sent in FAR from SGWC/Cn-SGWC.
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On N4 leg, DSCP marking is sent in FAR from SMF.
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For uplink packets, UPF applies the DSCP marking as per SMF configuration.
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For downlink packets, UPF applies the DSCP marking as per SGWC/Cn-SGWC configuration in GTPU header.
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For inner packet, DSCP marking is as per SMF configuration.
The SMF configuration/logic of sending the DSCP marking is similar as PGW-C. In case of the DSCP marking for the ECS charging action, priority is given to the charging action configuration for inner packet DSCP marking.