tc-hfsc(8) — Linux manual page
HFSC(8) Linux HFSC(8)
NAME
HFSC - Hierarchical Fair Service Curve's control under linux
SYNOPSIS
tc qdisc add ... hfsc [ default CLASSID ]
tc class add ... hfsc [ [ rt SC ] [ ls SC ] | [ sc SC ] ] [ ul SC ]
rt : realtime service curve
ls : linkshare service curve
sc : rt+ls service curve
ul : upperlimit service curve
• at least one of rt, ls or sc must be specified
• ul can only be specified with ls or sc
SC := [ [ m1 BPS ] d SEC ] m2 BPS
m1 : slope of the first segment
d : x-coordinate of intersection
m2 : slope of the second segment
SC := [ [ umax BYTE ] dmax SEC ] rate BPS
umax : maximum unit of work
dmax : maximum delay
rate : rate
For description of BYTE, BPS and SEC - please see UNITS section
of tc(8).
DESCRIPTION (qdisc)
HFSC qdisc has only one optional parameter - default. CLASSID
specifies the minor part of the default classid, where packets
not classified by other means (e.g. u32 filter, CLASSIFY target
of iptables) will be enqueued. If default is not specified,
unclassified packets will be dropped.
DESCRIPTION (class)
HFSC class is used to create a class hierarchy for HFSC
scheduler. For explanation of the algorithm, and the meaning
behind rt, ls, sc and ul service curves - please refer to
tc-hfsc(7).
As you can see in SYNOPSIS, service curve (SC) can be specified
in two ways. Either as maximum delay for certain amount of work,
or as a bandwidth assigned for certain amount of time. Obviously,
m1 is simply umax/dmax.
Both m2 and rate are mandatory. If you omit other parameters, you
will specify linear service curve.
SEE ALSO
tc(8), tc-hfsc(7), tc-stab(8)
Please direct bugreports and patches to: <netdev@vger.kernel.org>
AUTHOR
Manpage created by Michal Soltys (soltys@ziu.info)
COLOPHON
This page is part of the iproute2 (utilities for controlling
TCP/IP networking and traffic) project. Information about the
project can be found at
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If you have a bug report for this manual page, send it to
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iproute2 31 October 2011 HFSC(8)
Pages that refer to this page: tc-hfsc(7), tc(8), tc-stab(8)