22.214.171.124. Quality of service
This section of the domain XML provides setting quality of service. Incoming and outgoing traffic can be shaped independently. The
bandwidthelement can have at most one inbound and at most one outbound child elements. Leaving any of these children element out results in no QoS being applied on that traffic direction. Therefore, when you want to shape only domain's incoming traffic, use inbound only, and vice versa.
Each of these elements has one mandatory attribute
flooras described below).
averagespecifies average bit rate on the interface being shaped. Then there are two optional attributes:
peak, which specifies maximum rate at which interface can send data, and
burst, which specifies the amount of bytes that can be burst at peak speed. Accepted values for attributes are integer numbers.
The units for
peakattributes are kilobytes per second, whereas
burstis only set in kilobytes. In addition, inbound traffic can optionally have a
floorattribute. This guarantees minimal throughput for shaped interfaces. Using the
floorrequires that all traffic goes through one point where QoS decisions can take place. As such it may only be used in cases where the
interface type='network'/with a
nat, or no forward at all). It should be noted that within a virtual network, all connected interfaces are required to have at least the inbound QoS set (
averageat least) but the floor attribute does not require specifying
burstattributes still require
average. At the present time, ingress qdiscs may not have any classes, and therefore
floormay only be applied only on inbound and not outbound traffic.
To specify the QoS configuration settings, use a management tool to make the following changes to the domain XML:
... <devices> <interface type='network'> <source network='default'/> <target dev='vnet0'/> <bandwidth> <inbound average='1000' peak='5000' floor='200' burst='1024'/> <outbound average='128' peak='256' burst='256'/> </bandwidth> </interface> <devices> ...
Figure 20.51. Quality of service