Table 4-19. VLAN Tag Priority screen options.
Parameter Description
Quality of Service (QoS) Vlan
Tag Configuration
Used for setting up the QoS belongs to Vlan operation.
Port
User can set up the port (1~12) respectively to let Vlan Tag QoS
function work on them. If you would like to set up all ports at a time,
user is also allowed to choose “All” in the selection list to simplify
the procedure of configuration.
Bit 0, Bit 1, Bit 2
According to the arrangement of VLAN-tagged priority, it can form
8 kinds of traffics, including 0 0 0, 0 0 1, 0 1 0, 0 1 1, 1 0 0, 1 0 1, 1
1 0 and 1 1 1.
Class
8 kinds of traffic as mentioned above, user can set up High Priority
or Low Priority for each port respectively.
4.7.3 I
P
T
OS
C
LASSIFICATION
Another QoS function is the application of Layer 3 on network framework. We focus on TOS field of IP header.
There are three bits in TOS field. We means bit 5~7 of TOS field that we will use. 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. As long as we change bit 5~7 of TOS
field of IP header, we will create the 8 traffic packets we meant before. Moreover, we can set High priority or
Low priority for each traffic class. For instance, if we let TOS 0 0 0 be high priority and TOS 0 0 1 be Low
Priority, we sent in the packets that have bit 5~7 of TOS Field appears 0 0 0 from the port 2 and the packets that
have bit 5~7 of TOS Field appears 0 0 1 from the port 3. 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.
Table 4-20. IP TOS Classification screen options.
Parameter Description
Port
User can set up the port (1~12) respectively to let TOS QoS
function work on them. If you would like to set up all ports at a time,
user is also allowed to choose “All” in the selection list to simplify
the procedure of configuration.
Bit 0, Bit 1, Bit 2
According to the arrangement of Bit 5 ~ Bit 7 in TOS Field of IP
Header, it can form 8 kinds of traffics, including 0 0 0, 0 0 1, 0 1 0,
0 1 1, 1 0 0, 1 0 1, 1 1 0 and 1 1 1.
Class
8 kinds of traffic as mentioned above, user can set up High Priority
or Low Priority for each port respectively.
12-Port 1000BASE-TX L2 Managed PoE Switch with 2 SFP Dual Media Ports
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