Question: In a 5G network, how is the Average DL GTP packets delay in I-UPF (User Plane Function) calculated for performance measurements?
Option 1: By summing the transmission times of all DL GTP PDUs between the gNB-CU-UP and the UE, then dividing by the total number of UEs connected.
Option 2: Through periodic polling of the gNB-CU-UP's buffer size to estimate delay based on queue length and packet arrival rate.
Option 3: By sampling DL GTP PDUs, calculating the time difference between ingress and egress at the I-UPF for each sampled PDU, and then averaging these differences.
Option 4: Based on the S-NSSAI (Single Network Slice Selection Assistance Information) change frequency and associated 5QI (5G QoS Indicator) settings.
Explanation: This is correct because the calculation involves sampling DL GTP PDUs, determining the time difference for each sampled PDU between its arrival at the I-UPF's ingress and its sending from the egress, and then averaging these time differences, providing a direct measurement of the delay experienced by downlink traffic within the I-UPF.