Industrial Ethernet Switch User Manual
3onedata proprietary and confidential
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Copyright © 3onedata Co., Ltd.
6
QoS
6.1 QoS Classification
QoS provides four internal queues, each queue supports four different levels of traffic,
shorter persistence time of high-priority data packets in the switch, supports lower
latency for certain delay-sensitive traffic. According to port ID, MAC address, 802.1p
priority tags, DiONetServ and IP TOS, equipment can be abale to put the packets to
an appropriate level.
Users can select the QOS priority queue mechanism, the queue mechanism in two
ways: weighted Fair mode and strict mode.
Weighted Fair refers to this port sends message according to queue priority High,
Medium, Normal and low in proportion of 8:4:2:1 when some ports traffic is heavy. If
sending speed is less than bandwidth, the message of each priority queues can send
normally; if the port keeps sending in full speed, then the rest of the message of each
priority queues will be discarded.
Strict priority: it refers to QoS deals with the message from high priority to low priority.
If the low priority queues is full but the me
ssage of high priority queues don’t finish, the
message of low priority queues will be discarded; but if the speed of high priority
queue does not reach the port’s wire speed, then message of lower priority can send
one by one, and the data may be lost because of shortage of bandwidth. The ports
always finish all messages of high priority queues first then allow the message of
lower priority queues
Default priority is based on port priority, default priority is different from COS and TOS,
it did not have re
lationship with data package, it had relationship with switch port’s
priority. If the port’s priority is higher, the data packet will be transferred at first.
