Westell Inc. ULS3-C ユーザーズマニュアル

 

 
03/24/09 - DRAFT 
 
 

030-300554 Rev. C 

168 

    March 2009 

 

 
If you click the Quality of Service link in the Advanced screen and then click 802.1P Settings in the left submenu, 
the following screen appears.  
 
The IEEE 802.1p priority marking method is a standard for prioritizing network traffic at the data link/Mac sub-
layer. 802.1p traffic is simply classified and sent to the destination, with no bandwidth reservations established. 
 
The 802.1p header includes a 3-bit prioritization field, which allows packets to be grouped into eight levels of 
priority. By default, the highest priority is seven, which might be assigned to network-critical traffic. Values five and 
six may be applied to delay-sensitive applications such as interactive video and voice. Data classes four through one 
range from controlled-load applications down to “loss eligible” traffic. Zero is the value for unassigned traffic and is 
used as a best effort default, invoked automatically when no other value has been set. 
 
A packet can match more than one rule. This means the following: 
 

•  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.

 
Select the desired values from the drop-down lists, and then click Apply to save the settings.