Westell Inc. ULS3-C ユーザーズマニュアル

 

 
03/24/09 - DRAFT 
 
 

030-300554 Rev. C 

159 

    March 2009 

 

 

 
If you click the Quality of Service link in the Advanced screen and then click Traffic Priority in the left submenu, 
the following screen appears. This screen allows you to configure QoS to prioritize input and output traffic. 
 
Traffic Priority manages and avoids traffic congestion by defining inbound and outbound priority rules for each 
device on the Router. These rules determine the priority that packets, traveling through the device, will receive. QoS 
parameters (DSCP marking and packet priority) are set per packet, on an application basis. 
 
QoS can be configured using flexible rules, according to the following parameters:  

•  Source/destination IP address, MAC address, or host name  

•  Device  

•  Source/destination ports  

•  Limit the rule for specific days and hours  

 
The Router supports two priority marking methods for packet prioritization:  

•  DSCP 
•  802.1p Priority 

 
The matching of packets by rules, also known as Stateful Packet Inspection is connection-based and uses the 
Router’s firewall mechanism. Once a packet matches a rule, all subsequent packets with the same attributes receive 
the same QoS parameters, both inbound and outbound.  
 
A packet can match more than one rule. Therefore: 

•  The first class rule has precedence over all other class rules (scanning is stopped once the first rule is reached). 

•  The first traffic-priority (classless) rule has precedence over all other traffic-priority rules. 

•  There is no prevention of a traffic-priority rule conflicting with a class rule. In this case, the priority and DSCP 

setting of the class rule (if given) will take precedence. 

 
To set up a traffic priority rule, click the adjacent New Entry link for the input/output device you want to configure.