Question: In the context of 5G performance measurements, what triggers the calculation of IP Latency in Downlink (DL) within the gNB-DU for a specific RLC SDU packet?
Option 1: Arrival of any new IP packet at the gNB-DU for transmission to a UE.
Option 2: Arrival of an IP packet at the RLC ingress F1-U termination when there is no other prior data to be transmitted to the same UE in the gNB-DU.
Option 3: Completion of transmission of all pending packets to a UE, ensuring the buffer is clear before measuring latency for new packets.
Option 4: Receipt of a specific QoS level or S-NSSAI request that necessitates immediate latency measurement.
Explanation: The correct answer highlights the specific condition under which IP Latency in DL is measured within the gNB-DU, ensuring the latency reflects network performance when there are no pending transmissions to the same UE, crucial for accurate 5G performance assurance and optimization.