Alloy Computer Products GSM-8T16SFP - Manual (Page 49)

GSM Series User Manual
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Fig. 3-20
Function Name:
VLAN Tag Priority
Function Description:
The GSM Series switches allow the administrator to configure priority levels based on a
priority field found inside the VLAN Tag. This priority field contains 3 bits which allow a
total of 8 priority levels to be configured: 000, 001, 010, 011, 100, 101, 110 and 111.
We can then set a High or Low priority level for each of these 8 traffic classes. For
instance, if we set 000 as a High priority and 001 as a Low priority and then configure
ports 1, 2 and 3 to belong to VLAN group 2, traffic that is sent from port 1 with a class
field of 000 and a VID of 2 and traffic that is sent from port 2 with a class field of 001 and
a VID of 2 at 1Gb, and congestion occurs, packets will be dropped from port 2 because
of the lower priority.
Parameter Description:
Port:
Select the port you wish to configure your priority levels for, if you wish to
configure all ports at the same time, select all from the drop down box.
Bit 0, Bit 1, Bit 2:
According to the IEEE 802.1p standard the VLAN Tagged priority can be set into
8 types of traffic classifications, including 000, 001, 010, 011, 100, 101, 110 and
111.
Class:
You can now assign a High or Low priority level to each of the 8 traffic classes.