Transmit queues are logical partitions of an Ethernet port¡¯s egress bandwidth. Data streams are assigned to queues based on their traffic class, then sent as scheduled by port and transmit settings. Sand platform switches have eight queues, 0 through 7, and all queues are exposed through the CLI. However, queue 7 is not user-configurable. Queue 7 is always mapped to traffic class 7, which is reserved for control plane traffic. This feature allows tx-queue 7 to be configurable. As of 4.33.0F, a limited set of features are configurable on tx-queue 7.

Latency and drop information help determine if there is a loss in a particular flow and where the loss occurred. A Service Node action configured as a DMF-managed service that, given two separate taps or spans in the production network, can measure the latency of a flow traversing through these two points. It can also detect packet drops between two points in the network if the packet only appears on one point within a specified time frame, currently set to 100ms.

The low latency tx-queue scheduler profile feature aims to provide an alternative operating mode for the queue that is fine-tuned for reduced latency. This involves a tradeoff between achieving lower latency and being able to sustain full throughput over a large number of flows.

This feature allows setting the desired maximum VOQ latency. Drop probabilities are adjusted in hardware to meet this limit.