Reference Manual

NAME

setth - set an interface input queue threshold

setlow - set an interface low-water mark for buffer usage

setls - set an interface sleep time for when the low-water mark is reached

SYNOPSIS
setth  [ifn | all] [value]
setlow [ifn | all] [value]
setls  [ifn | all] [msec]
STATUS
DESCRIPTION
Command setth sets an input queue threshold for a specified ifn. When the threshold is reached, incoming packets are discarded until the queue has been serviced. This reduces buffer bloat at the expense of throughput.

Command setlow sets a low-water mark for buffer usage of a specified ifn. When the low-water mark is reached, the interface input process attempts to wake the IP process so that packets are routed and buffers returned to the pool. Several methods are used to achieve this, including an event mechanism, a SwitchToThread mechanism and, as a last resort, a short sleep. The effectiveness of a particular method depends on the CPU type and its level of multi-threading support.

Command setls sets the short sleep duration for the low-water sleep case. The duration should normally not exceed 5-10 msec. Per default, the sleep timer has a precision of 1 msec.

NOTES
The above commands are experimental in nature and should be carefully tested with network speed testing software before production use. It is recommended that a command line speed testing tool such as Speedtest CLI be used for this purpose.

Low buffer bloat is thought to reduce network latency and thus improve the behaviour of video conferencing and streaming applications.

The setlow and the setls commands also clear the relevant counters when a new value is set.

The network buffer pool size is 256, the default low-water mark is 16 and the default short sleep time is 0 msec.

SEE ALSO
Flow control