2.1.7 Quality of Service
There are 4 class priorities that can be set for each port: Low, Normal, Medium and High. Because there are 8
priority levels (0 ~ 7) for each port, so 8 priorities map into 4 classes must be done in this QoS control.
There are 3 QoS Mode can be chosen: Port-based, 802.1P and DSCP. The frames send not only per priority
setting but also per Queue Mode setting.
Strict Mode
means highest priority setting gets first service to send
frames, the lower priority frames must wait until all other higher priority frames are sent (serviced), and then it
gets service.
WRR Mode
means different priorities are with different weighting to get service, that is, within a
time period. The service times (chance) are a ratio among these 4 classes, user may choose one of preset
setting from the manual. A default diagram with Strict Queue Mode is shown below
.
Choose the port-based priority level for each port you want to set, and then ports will get priority service as
setting. For example, under Strict Mode, Port 5,6,7,8 are set as “ low ”, port 1,2,3,4 are set as high, medium,
normal and low. Then, after “Apply”, usually port 1 will get service at most of time and even all of the time.
When users choose the 802.1P priority, this means frames are with VLAN Tag inside the switch. The
priority in the Tagged frame (4 bytes Tag in total) must be set by application program, or set by user in
Default Priority Table if the device connected to that port is legacy device which does not support Tag. That
is, user must set Priority for legacy device at each legacy port. 8 priority levels map into 4 classes also
must be done the same as explained in previous paragraph.
AirLive Ether-GSHTW v2 / 8TW+v2 User’s Manual
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