ConnectGear gs-1124 Betriebsanweisung

 

The 

switch

 offers powerful QoS function. This function supports VLAN-tagged 

priority that can make precedence of 8 priorities, TOS field of IP header (equal 
DSCP low 3 bits) on Layer 3 of network framework, 6 kinds of special network 
transmission events on Layer 4 and IP DiffServe QoS service.  

In Quality of Service (QoS) Configuration, there is one option named” Default 

Class”. As you had selected one of the four QoS functions, then some packets that 
did not belong to this QoS 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. 

 

Fig. 4-13 

 
 
Function name: 

VLAN Tag Priority 

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 0, 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 in the 
packets that have vlan-tagged Field appears 0 0 0 and VID equals 2 from the 
port 2 and the packets that have vlan-tagged Field appears 0 0 1 and VID 
equals 2 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. For the use of VLAN Tag Priority function, please press Configure at 
the right section for setting in advance.