User`s manual

PT-G7509 User’s Manual Featured Functions
3-48
Configuring Traffic Prioritization
Quality of Service (QoS) provides a traffic prioritization capability to ensure that important data is
delivered consistently and predictably. The PT-G7509 can inspect IEEE 802.1p/1Q layer 2 CoS
tags, and even layer 3 TOS information, to provide a consistent classification of the entire network.
The PT-G7509’ QoS capability improves your industrial network’s performance and determinism
for mission critical applications.
QoS Classification
The PT-G7509 supports inspection of layer 3 TOS and/or layer 2 CoS tag information to
determine how to classify traffic packets.
Queuing Mechanism
Setting Description Factory Default
Weight Fair the PT-G7509 has 4 priority queues. In the weight fair
scheme, an 8, 4, 2, 1 weighting is applied to the four
priorities. This approach prevents the lower priority
frames from being starved of opportunity for
transmission with only a slight delay to the higher
priority frames.
Strict In the Strict-priority scheme, all top-priority frames
egress a port until that priority’s queue is empty, and
then the next lower priority queue’s frames egress. This
approach can cause the lower priorities to be starved of
opportunity for transmitting any frames but ensures all
high priority frames to egress the switch as soon as
possible.
Weight Fair