Quality Of Service Introduction; Overview - HP GbE2c - Blc Layer 2/3 Fiber SFP Option Application Manual
Ethernet blade switch for c-class bladesystem
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Also See for GbE2c - Blc Layer 2/3 Fiber SFP Option:
- Interface manual (209 pages) ,
- Command reference manual (175 pages) ,
- Cli reference manual (153 pages)
Table of Contents
Quality of Service
Introduction
Quality of Service features allow you to allocate network resources to mission-critical applications at the expense of
applications that are less sensitive to such factors as time delays or network congestion. You can configure your
network to prioritize specific types of traffic, ensuring that each type receives the appropriate Quality of Service
(QoS) level.
The following topics are discussed in this section:
Quality of Service Overview
Using ACL Filters
Using DSCP Values to Provide QoS
Using 802.1p Priorities to Provide QoS
Queuing and Scheduling
Overview
QoS helps you allocate guaranteed bandwidth to the critical applications, and limit bandwidth for less critical
applications. Applications such as video and voice must have a certain amount of bandwidth to work correctly; using
QoS, you can provide that bandwidth when necessary. Traffic for applications that are sensitive to timing out or
cannot tolerate delay can be assigned to a high-priority queue.
By assigning QoS levels to traffic flows on your network, you can ensure that network resources are allocated where
they are needed most. QoS features allow you to prioritize network traffic, thereby providing better service for
selected applications.
The following figure shows the basic QoS model used by the GbE2c.
Figure 11
QoS model
Ingress
Ports
The GbE2c uses the Differentiated Services (DiffServ) architecture to provide QoS functions. DiffServ is described in
IETF RFCs 2474 and 2475.
With DiffServ, you can establish policies to direct 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 GbE2c can classify traffic by reading the 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 GbE2c 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 GbE2c QoS model works as follows:
Classify traffic:
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)
Meter
Classify
Packets
Traffic
ACL
ACL
Filter
Meter
Perform
Queue and
Actions
Schedule
Drop/Pass/
COS
Re-Mark
Queue
Egress
Quality of Service 70
Table of Contents
Troubleshooting
