Lenovo ThinkSystem NE2552E, Application Manual

Page: 220 / 574

220
NE2552E Application Guide for ENOS 8.4
With DiffServ, you can establish policies for directing traffic. A policy is a
traffic ‐ controlling mechanism that monitors the characteristics of the traffic (for
example, its source, destination, and protocol) and performs a controlling action on
the traffic when certain characteristics are matched.
The NE2552E can classify traffic by reading the DiffServ Code Point (DSCP) or
IEEE 802.1p priority value, or by using filters to match specific criteria. When
network traffic attributes match those specified in a traffic pattern, the policy
instructs the NE2552E to perform specified actions on each packet that passes
through it. The packets are assigned to different Class of Service (COS) queues and
scheduled for transmission.
The basic NE2552E QoS model works as follows:
 Classify traffic:

Read DSCP

Read 802.1p Priority

Match ACL filter parameters
 Meter traffic:

Define bandwidth and burst parameters

Select actions to perform on in ‐ profile and out ‐ of ‐ profile traffic
 Perform actions:

Drop packets

Pass packets

Mark DSCP or 802.1p Priority

Set COS queue (with or without re ‐ marking)
 Queue and schedule traffic:

Place packets in one of the available COS queues

Schedule transmission based on the COS queue weight