Obihai OBi100 Administration Manual page 18

In addition to the three priority classes, a fourth priority class known as the Restricted class is available. The Restricted class
has the highest priority among the four classes. The guaranteed bandwidth for the Restricted class is allocated separately
with its own parameter in the configuration.
Note that the total guaranteed bandwidth allocated to all the four priority classes is equal to the total available uplink
bandwidth, which must be specified correctly in the UpStreamBandwidth parameter in the QoS settings for QoS to work
properly.
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