Packet Flow

When an Ethernet packet enters Chimera, it is assigned to a flow. Impairments are configured independently for every flow. Every Rx port has a default flow. Additional flows can be added to the Rx port by configuring a corresponding flow filter. A maximum of 7 flow filters can be configured on every Rx port. Packets which match the flow filter, will be mapped to the corresponding flow. The flow filters are prioritized so packets are first matched against the filter of flow #7, subsequently flow filter #6 and finally filter #1.

Packets which do not match any flow filter, will be assigned to the port default flow (= flow #0).

This results in a total of maximum 8 flows for every port independent of port speed.

The Chimera flows as seen in XenaManager are illustrated in Fig. 159.

Fig. 159 Chimera flow filters in XenaManager

Once the packet is mapped to a flow, it will pass through the associated impairment pipeline (see Overview).

At the output of the impairment pipeline, packets from different flows will be merged into a common packet flow, which is transmitted to the output port. This is illustrated in Fig. 160.

Fig. 160 Chimera packet flow and impairments.