This article provides the information about "How does Express Path Process the Traffic?"
When the first packet arrives at an interface, the network processor forwards it to the central point (CP). The central point in turn forwards the packet to the SPU. The SPU then creates a session on the network processor and verifies if the traffic qualifies for the Express Path session or a normal session.
If the traffic qualifies for Express Path processing, an Express Path session for the traffic is created in the SPU. The Express Path session processes the fast-path packets in the network processor, and the packets exit from the network processor.
If the traffic doesn't qualify for Express Path processing, the SPU creates a normal session. The normal session forwards packets from the network processor to the SPU for fast-path processing.