Back pressure – GarrettCom MNS-6K 4.1.4 User Manual
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M A G N U M 6 K S W I T C H E S , M N S - 6 K U S E R G U I D E 
 
where 
 xonlimit can be from 3 to 30, default value is 4 
 xofflimit from 3 to 127, default value is 6 
 
Syntax show flowcontrol 
Back Pressure
Back Pressure is for half duplex operations and the controls provided indicates the 
number of buffers allowed for incoming traffic before a xon/xoff message is sent. 
 
Disabled (default) – The port will not use back pressure based flow control mechanisms. 
Enabled – The port uses 802.3 Layer 2 back off algorithms. Back pressure based 
congestion control is possible only on half-duplex, 10-Mbps Ethernet ports. Other 
technologies are not supported on Magnum 6K family of switches. 
 
Syntax backpressure rxthreshold=
where 
 rxthreshold value can be from 3 to 127, default is 28 
 
Syntax show backpressure 
 
Backpressure and Flow control are to be used in networks in which all 
devices and switches can participate in the flow control and back pressure 
recognition. In most networks, these techniques are not used as not all 
devices can participate in the flow control methods and notifications. 
Alternately, QoS and other techniques are widely used today. 
 
In the example below, the Magnum 6K family of switches are setup with flow control and 
back pressure. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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