RuggedCom RS400 manual Forwarding Phase, Determining The CoS Of a Received Frame

Classes of Service

Received

Frame MAC Address in

Static MAC Address

Table?

Y

Use CoS

Configured for

the MAC address

No	Frame	No		No	Use Port Default	To CoS
			IP Frame ?			Queues of
	tagged ?				CoS
						Egress Ports
	Y		Y
			Use TOS	No
			DSCP ?
			Y
			Use DSCP-to-
			CoS Mapping
	Use Priority-to-
	CoS Mapping

Figure 124: Determining The CoS Of A Received Frame

After inspection, the frame is the forwarded to the egress port for transmission.

7.1.2 Forwarding Phase

The inspection phase results in the CoS of individual frames being determined. When these frames are forwarded to the egress port they are collected into one of the priority queues according to the CoS assigned to each frame.

CoS weighting selects the degree of preferential treatment that is attached to different priority queues. The ratio of the number of higher CoS to lower CoS frames transmitted can be programmed. If desired, the user can program that lower CoS frames are transmitted only after all higher CoS frames have been serviced.

ROS™ v3.5 186 RS400