The output of the show pools network-egress command provides a snapshot of the buffer usage for each forwarding class (FC) queue on a specific network port. The Total-Shared column is critical; it shows the number of packets currently held in the shared portion of the buffer pool. A queue only uses the shared buffer when its dedicated Committed Buffer Size (CBS) is exhausted due to congestion.

For FCs "be" and "l2", the Total-Shared values are 100 and 50, respectively. This non-zero value confirms that these queues have exceeded their CBS and are actively queuing packets in the shared buffer. For FC "ef", the Total-Shared value is 0, indicating that it is not currently using the shared buffer, and therefore, its traffic is not experiencing congestion-related queuing delays.

A. The existence of this detailed output, showing multiple forwarding classes with specific buffer allocations (CBS/MBS), is direct evidence that a Quality of Service (QoS) policy is configured and active.

D. The Oper MBS (Operational Maximum Burst Size) of 100 for FC "l1" indicates it is permitted to use the shared buffer pool. The current usage is zero, but this does not mean it can never use it.

E. The Out-Of-Profile column shows the number of out-of-profile packets currently buffered, not dropped. This output provides no information on whether any packets are being dropped.

1. Nokia 7450 ESS, 7750 SR, 7950 XRS, and VSR Quality of Service Guide, Release 21.10.R1, Section: "Monitoring Queue and Pool Statistics".

This guide explains that the show pools command is used to view the buffer pool statistics for queues. It details that when a queue's CBS is depleted, it contends for resources from the shared part of the buffer pool, up to its MBS. A non-zero value in the shared usage columns (like Total-Shared) indicates active queuing beyond the committed portion, which directly supports the correctness of answers B and C.

2. Nokia 7750 SR OS System Management Guide, Release 21.10.R1, Section: "show pools".

The command reference for show pools defines the output fields. The Total-Shared field is described as "The current number of buffers in use from the shared part of the pool." This confirms that values of 100 and 50 for "be" and "l2" mean they are actively using shared buffers (queuing), while a value of 0 for "ef" means it is not. The Oper MBS field is defined as the operational percentage of the shared buffer a queue can use, which refutes option D.