Netgear GS724TS-100NAS 사용자 설명서

다운로드
페이지 275
128
   
|    
Chapter 4:  Configuring Quality
 of
 Service 
 
GS716Tv2 and GS724Tv3 Software Administration Manual 
Class of Service
The Class of Service (CoS) queueing feature lets you directly configure certain aspects of 
switch queueing. This provides the desired QoS behavior for different types of network traffic 
when the complexities of DiffServ are not required. The priority of a packet arriving at an 
interface can be used to steer the packet to the appropriate outbound CoS queue through a 
mapping table. CoS queue characteristics that affect queue mapping, such as minimum 
guaranteed bandwidth, or transmission rate shaping are user-configurable at the queue (or 
port) level.
Four queues per port are supported. 
From the Class of Service link under the QoS tab, you can access the following pages:
Basic CoS Configuration
Use the Trust Mode Configuration page to set the class of service trust mode of an interface. 
Each port in the switch can be configured to trust one of the packet fields (802.1p or IP 
DSCP), or to not trust any packet’s priority designation (untrusted mode). If the port is set to a 
trusted mode, it uses a mapping table appropriate for the trusted field being used. This 
mapping table indicates the CoS queue to which the packet should be forwarded on the 
appropriate egress port(s). Of course, the trusted field must exist in the packet for the 
mapping table to be of any use, so there are default actions performed when this is not the 
case. These actions involve directing the packet to a specific CoS level configured for the 
ingress port as a whole, based on the existing port default priority as mapped to a traffic class 
by the current 802.1p mapping table.
Alternatively, when a port is configured as untrusted, it does not trust any incoming packet 
priority designation and uses the port default priority value instead. All packets arriving at the 
ingress of an untrusted port are directed to a specific CoS queue on the appropriate egress 
port(s), in accordance with the configured default priority of the ingress port. This process is 
also used for cases where a trusted port mapping is unable to be honored, such as when a 
non-IP packet arrives at a port configured to trust the IP DSCP value.
To display the Basic CoS Configuration page, click QoS 
 Basic  CoS Configuration.