0 PDU session Identity value 2 PDU session Identity value 3 PDU session Identity value 4 PDU session Identity value 5 000011O PDU session Identity value 6 PDU session Identity value 7 PDU session Identity value 8 PDU session Identity value 9 PDU session Identity value 10 PDU session Identity value 11 PDU session Identity value 12 PDU session Identity value 13 PDU session Identity value 14 PDU session Identity value 15 All other values are reserved (see NOTE). NOTE: Values 64 up to and Including 95 are used by the core network as specified in TS 29.571 [37] and are unavailable for future usage in NAS. PDU session Identity octet 1 Figure 2.17 - PDU session ID The PDU session can be of the IPv4, IPv6, IPv4v6, unstructured, or Ethernet type. End-to-End Architecture Components, Concepts, Security, and Transport 5G QoS To understand the 5G QoS better, it is best to start with the terminologies used to describe it: Parameter Description QoS flow identification, used to identify a flow within PDU session. A scalar that is used as a reference to 5G QoS characteristcs; access node- specific parameters that control QoS forwarding treatment for the QoS flow Includes the priority level, pre-emption capability, and the pre-emption vulnerability Flow bit rate Guaranteed Flow Bit Rate (GFBR) - UL and DL Maximum Flow Bit Rate (MFBR) - UL and DL Aggregate bit rate Per-Session Aggregate Maximum Bit Rate (Session AMBR) - SMF gets it from UDM Per UE Aggregate Maximum Bit Rate (UE-AMBR) - the AMF gets it from UDM then passes to RAN Maximum Packet Maximum rate for lost packets for the QoS flow that can be tolerated in Loss Rate the uplink and downlink (GFBR only) Table 2.1 - QoS parameter description Every PDU session in the 5GS has one or more QoS flows and each of these flows is identified by its QFI. The SMF allocates the QFI based on the QoS needed for the particular user traffic. On the radio interface, on the other hand, multiple QoS flows can be sent into one Dedicated Resource Bearer (DRB). Only one GTPU tunnel is formed betwee