BLADE OS™ Application Guide HP GbE2c Ethernet Blade Switch for c-Class BladeSystem Version 5.1 Advanced Functionality Software

BMD00113, September 2009 137
CHAPTER 8
Quality of Service
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:
 “QoS Overview” on page 137
 “Using ACL Filters” on page 139
 “Using DSCP Values to Provide QoS” on page 148
 “Using 802.1p Priorities to Provide QoS” on page 151
 “Queuing and Scheduling” on page 153
QoS 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. Also, you
can put a high priority on applications that are sensitive to timing out or cannot tolerate delay by
assigning that traffic 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.
Figure 14 shows the basic QoS model used by the HP GbE2c Ethernet Blade Switch (GbE2c).