Packet fast path requirements

Packets within the session must then also meet packet requirements.

• Incoming packets must not be fragmented.
• Outgoing packets must not require fragmentation to a size less than 385 bytes. Because of this requirement, the configured MTU (Maximum Transmission Unit) for a network processor’s network interfaces must also meet or exceed the network processors’ supported minimum MTU of 385 bytes.

Mixing fast path and non-fast path traffic

If packet requirements are not met, an individual packet will be processed by the FortiGate CPU regardless of whether other packets in the session are offloaded to the NP6.

Also, in some cases, a protocol’s session(s) may receive a mixture of offloaded and non-offloaded processing. For example, VoIP control packets may not be offloaded but VoIP data packets (voice packets) may be offloaded.

NP6 processors and traffic shaping

NP6-offloaded traffic supports traffic shaping just like any other traffic with one exception: configuring in bandwith traffic shaping has no effect on NP6 accelerated traffic. In bandwidth traffic shaping sets the bandwidth limit for incoming traffic for an interface.

Out bandwidth traffic shaping is supported. Out bandwidth traffic shaping sets the bandwidth limit for outgoing traffic for an interface. You can use the following command to configure out bandwidth traffic shaping:

config system interface edit port1

set outbandwidth 2000 end