FortiController–5902D fast path architecture

The FortiController-5902D NP6 network processors and integrated switch fabric (ISF) provide hardware acceleration by offloading load balancing from the primary FortiController-5902D CPU. Network processors are especially useful for accelerating load balancing of TCP and UDP sessions.

The first packet of every new session is received by the primary FortiController-5902D and the primary FortiController-5902D uses its load balancing schedule to select the worker that will process the new session. This information is passed back to an NP6 network processor and all subsequent packets of the same sessions are offloaded to an NP6 network processor which sends the packet directly to a subordinate unit. Load balancing is effectively offloaded from the primary unit to the NP6 network processors resulting in a faster and more stable active-active cluster.

Traffic accepted by the FortiController-5902D F1 to F4 interfaces is that is processed by the primary FortiController-5902D is also be offloaded to the NP6 processors.

Individual FortiController-5902D interfaces are not mapped to NP6 processors. Instead an Aggregator connects the all fabric interfaces to the ISF and no special mapping is required for fastpath offloading.

Fabric Backplane

F1/2 to  F13

Aggregator

Integrated Switch Fabric

FortiASIC NP6

FortiASIC NP6

System Bus