Design

Software architecture

Fast Path QoS Advanced uses computer cores dedicated to scheduling. All usual fast path processing (packet receive, routing, filtering, encapsulation, IPsec, QoS classification…) is processed by worker cores, following a run-to-completion model.

Then, if a packet needs to be sent out a physical interface with QoS enabled, it is enqueued in intercore packet queues, one per QoS class, after an optional per-interface and per-class metering stage.

The QoS class queues are polled by the scheduler cores, and packets are send on the physical network interface according to a scheduling algorithm.