Technical data
4. Packages
For upstream class number two should be the default class. The network device eth0 is set
to 10Mibit/s.
QOS_CLASS_N='2'
QOS_CLASS_1_PARENT='0'
QOS_CLASS_1_MINBANDWIDTH='127Kibit/s'
QOS_CLASS_1_MAXBANDWIDTH='128Kibit/s'
QOS_CLASS_1_DIRECTION='up'
QOS_CLASS_1_PRIO=''
This is the class for ACK (acknowledgement) packets. ACK packets are rather small and thus
need only a minimum bandwidth. Because they should not be affected in any way they get
127Kibit/s. 1Kibit/s is left for the rest.
QOS_CLASS_2_PARENT='0'
QOS_CLASS_2_MINBANDWIDTH='1Kibit/s'
QOS_CLASS_2_MAXBANDWIDTH='128Kibit/s'
QOS_CLASS_2_DIRECTION='up'
QOS_CLASS_2_PRIO=''
This class is for everything else (except ACK packets). The bandwidth that is left is 1Kibit/s
(128-127=1). We don’t limit it to 1Kibit/s though, the class is limited by the entry
QOS_CLASS_2_MAXBANDWIDTH='128Kibit/s'
Because our first class never can use all of its bandwidth there will be something left over
which then gets allocated to the second class. If upstream should be divided some more
(prominent use case) all other classes have to be subclasses “under” this class. Of course
QOS_INTERNET_DEFAULT_UP has to be adapted then.
QOS_FILTER_N='1'
QOS_FILTER_1_CLASS='1'
QOS_FILTER_1_IP_INTERN=''
QOS_FILTER_1_IP_EXTERN=''
QOS_FILTER_1_PORT=''
QOS_FILTER_1_PORT_TYPE=''
QOS_FILTER_1_OPTION='ACK'
This filter filters all packets matching option ACK (i.e. ACK packets). By specifying QOS_-
FILTER_1_CLASS=’1’ we achieve that all these packets filtered are sent to class 1.
For testing purposes look for one or more good up- and download sources that can produce
full load for up- as well as for downstream. Have a look at the traffic display in ImonC. Try
this once with and once without QoS.
Downstream should not or not as much decline as without this configuration. It could
get even better by declining upstream bandwidth in steps of Kibibits and analyze the ef-
fect. I reached my optimum at 121Kibit/s (no declining downstreams anymore). Of course
MAXBANDWIDTH- and MINBANDWIDTH- values of all classes have to be adapted accord-
ingly.
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