Qos Configuration; Per Port Priority; Vlan Tag Priority - Black Box 12-Port 1000BASE-TX L2 Managed PoE Switch User Manual

4.7 QoS (Quality of Service) Configuration
The switch offers powerful 5 kinds of QoS functions. There are Per Port Priority that you can assign each port
to different precedence, VLAN Tag priority that can make precedence of 8 priorities, IP TOS Classification, IP
TCP/UDP Port Classification and IP DiffServe Classification.
In Quality of Service (QoS) Configuration, there is one option named Default Class. As you had selected one
of the five QoS functions, then some packets that did not belong to this QoS setting would be viewed as Default
Class. For instance, if you set QoS function as VLAN Tag Priority mode, and then choose Default Class as High,
finally, the priority of the packets with no tag will be considered as High priority precedence. The initial value
of the Default Class is High.
4.7.1 P P P
ER ORT RIORITY
We can assign QoS Priority, including High and Low for each port. For example, if we transmit IP packets from
Port 2 and Port 3 at the speed of 1 Gbps to Port 1, and set the Class of Port 2 as High and Port 3 as Low, then
the packets of Port 3 will be dropped when the congestion happens because Port 2 owns higher precedence of
transmitting packets.
Parameter
Port No
Class
4.7.2 V T P
LAN AG RIORITY
In vlan tag, there are 3 bits belonging to priority. According to these 3 bits, we could arrange 8 traffics –0 0 0, 0
0 1, 0 1 0, 0 1 1, 1 0 0, 1 0 1, 1 1 0, 1 1 1. We can set High priority or Low priority for each traffic class. For
instance, if we let VLAN-tagged priority 0 0 0 be high priority and VLAN-tagged priority 0 0 1 be Low Priority,
and then make port 1, 2, 3 be in the vlan 2. We sent the packets that have the value 0 0 0 in vlan-tagged field
and VID equals 2 from the port 2 and the packets that have the value 0 0 1 in vlan-tagged field and VID equals 2
from the port 3 into the switch. We let the two kinds of packets be transmitted for port 1 until the port results
in congestion. The result is that the packets will be dropped partially from the port 3 because the packets that
belong to Low Priority. For the use of VLAN Tag Priority function, please press Configure button at the right
section for setting in advance.
Table 4-18. Per Port Priority screen options.
Description
User can choose the port (1~12) respectively with Priority Class on
Per Port Priority function.
User can set up High Priority or Low Priority for each port
respectively.
CHAPTER 4: Web-Based Management
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