Specifications

Waters Network Systems User’s Manual Page 48
GSM-2108/GSM-1008SFP
Parameter description:
Quality of Service (QoS) VLAN Tag Configuration:
Used for setting up the QoS belongs to VLAN operation.
Port:
Set the ports (1~8) respectively to allow the VLAN Tag QoS function to work. Use Select All to
set all the ports at the same time.
Bit 0, Bit 1, Bit 2:
According to the arrangement of VLAN-tagged priority, eight types of traffic can be formed,
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:
Set High Priority or Low Priority for each port respectively for the eight types of traffic.
Function name:
IP ToS Classification
Function description:
Another QoS function is the application of Layer 3 on network framework. This focus is on the TOS
field of the IP header. There are three bits in TOS field. Bit 5~7 of TOS field will be used. According
to these three bits, we could arrange eight 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 eight traffic packets. High
priority or Low priority can be set for each traffic class. For instance, if we set TOS 0 0 0 to high
priority and TOS 0 0 1 to Low Priority the packets that have bit 5~7 of TOS Field are 0 0 0 from Port
2 and the packets that have bit 5~7 of TOS Field are 0 0 1 from Port 3. The two kinds of packets are
transmitted for Port 1 until the port results in congestion. The result is that the packets will be
dropped partially from Port 3 because the packets belong to Low Priority.
Figure 5.20 – QoS ToS Configuration
Parameter description:
Quality of Service (QoS) ToS Configuration:
Used for setting the QoS in Layer 3.