5.32.5.1a Address of PMF messages

As described in clause 5.32.5.2, 5.32.5.2a and 5.32.5.3, a UE and UPF may exchange PMF messages to measure access performance and report access availability/unavailability. When the UE and UPF exchanges PMF message, source and destination address of the PMF messages shall be assigned as follows:

1. In the case of a MA PDU Session of IP type:

• If access performance measurements are performed only over the QoS Flow associated with the default QoS rule, the PMF in the UE sends PMF messages to the PMF in the UPF over UDP/IP. The destination IP address is the IP address contained in the Measurement Assistance Information and the destination UDP port is one of the two UDP ports contained in the Measurement Assistance Information. One UDP port is used for sending PMF messages to UPF over 3GPP access and the other UDP port is used for sending PMF messages to UPF over non-3GPP access. The source IP address is the IP address assigned to UE for the MA PDU Session and the source UDP port is a UDP port that is dynamically allocated by the UE for PMF communication. This source UDP port in the UE remains the same for the entire lifetime of the MA PDU Session.

If access performance measurements per QoS Flow is performed, the Measurement Assistance Information contains UDP ports, one for each QoS Flow and access combination. When the UE sends PMF message over a QoS Flow of an access, the UE shall set the destination UDP port as the UDP port for the QoS Flow and the access in Measurement Assistance information.

• If access performance measurements are performed only over the QoS Flow associated with the default QoS rule, the PMF in the UPF sends PMF messages to the PMF in the UE over UDP/IP. The source IP address is the same IP address as the one provided in the Measurement Assistance Information and the source UDP port is one of the two UDP ports as provided in the Measurement Assistance Information. One UDP port is used for sending PMF messages to UE over 3GPP access and the other UDP port is used for sending PMF messages to UE over the non-3GPP access. The destination IPv4 address is the IPv4 address assigned to UE for the MA PDU Session (if any) and the destination IPv6 address is an IPv6 address selected by the UE from the IPv6 prefix assigned for the MA PDU Session (if any). The destination UDP port is the dynamically allocated UDP port in the UE, which is contained in all PMF messages received from the UE.

If access performance measurements per QoS Flow is performed, when the UPF sends PMF message over a QoS Flow of an access, the UPF shall set the source UDP port with the UDP port for the QoS Flow and the access as the one for the QoS Flow and the access provided in Measurement Assistance information.

• If the UE receives Measurement Assistance Information, the UE shall inform the network via the user plane about the UE's dynamically allocated UDP port and the IPv6 address if IPv6 is used for PMF messages, so that it is possible for the UPF to know the UE's IPv6 address (if applicable) and dynamically allocated UDP port as soon as the MA PDU Session has been established.

NOTE 1: Regardless of whether access performance measurements per QoS Flow is applied or not, the UE only allocates a single UDP port for PMF messages.

2. In the case of a MA PDU Session of Ethernet type:

• The PMF in the UE sends PMF messages to the PMF in the UPF over Ethernet. The Ethertype is the Ethertype contained in the Measurement Assistance Information. If access performance measurements are performed only over the QoS Flow associated with the default QoS rule, the destination MAC address is one of the two MAC addresses contained in the Measurement Assistance Information. One MAC address is used for sending PMF messages to UPF over 3GPP access and the other MAC address is used for sending PMF messages to UPF over non-3GPP access. The source MAC address is a MAC address of the UE, which remains the same for the entire lifetime of the MA PDU Session.

If access performance measurements per QoS Flow is performed, Measurement Assistance Information contains MAC addresses for each QoS Flow and each access. When the UE sends PMF message over a QoS Flow of an access, the UE shall set the destination MAC address as the MAC address for the QoS Flow and the access in Measurement Assistance information.

• The PMF in the UPF sends PMF messages to the PMF in the UE over Ethernet. The Ethertype is the same Ethertype as the one provided in the Measurement Assistance Information. If access performance measurements are performed only over the QoS Flow associated with the default QoS rule, the source MAC address is one of the two MAC addresses as provided in the Measurement Assistance Information. One MAC address is used for sending PMF messages to UE over 3GPP access and the other MAC address is used for sending PMF messages to UE over non-3GPP access. The destination MAC address is the MAC address of the UE, which is contained in all PMF messages received from the UE.

If access performance measurements per QoS Flow is performed, when the UPF sends PMF message over a QoS Flow of an access, the UPF shall set the source MAC address with the MAC address for the QoS Flow and the access as the one for the QoS Flow and the access provided in Measurement Assistance information.

• If the UE receives Measurement Assistance Information, the UE shall inform the network via the user plane about the UE's MAC address so that it is possible for the UPF to know the UE's MAC address as soon as the MA PDU Session has been established.

NOTE 2: Regardless of whether access performance measurements per QoS Flow is applied or not, the UE only use a single MAC address.