.TH HFSC 8 "31 October 2011" iproute2 Linux

.

.SH NAME

HFSC \- Hierarchical Fair Service Curve's control under linux

.

.SH SYNOPSIS

.nf

tc qdisc add ... hfsc [ \fBdefault\fR CLASSID ]

tc class add ... hfsc [ [ \fBrt\fR SC ] [ \fBls\fR SC ] | [ \fBsc\fR SC ] ] [ \fBul\fR SC ]

\fBrt\fR : realtime service curve

\fBls\fR : linkshare service curve

\fBsc\fR : rt+ls service curve

\fBul\fR : upperlimit service curve

\(bu at least one of \fBrt\fR, \fBls\fR or \fBsc\fR must be specified

\(bu \fBul\fR can only be specified with \fBls\fR or \fBsc\fR

.

.IP "SC := [ [ \fBm1\fR BPS ] \fBd\fR SEC ] \fBm2\fR BPS"

\fBm1\fR : slope of the first segment

\fBd\fR  : x\-coordinate of intersection

\fBm2\fR : slope of the second segment

.PP

.IP "SC := [ [ \fBumax\fR BYTE ] \fBdmax\fR SEC ] \fBrate\fR BPS"

\fBumax\fR : maximum unit of work

\fBdmax\fR : maximum delay

\fBrate\fR : rate

.PP

.fi

For description of BYTE, BPS and SEC \- please see \fBUNITS\fR

section of \fBtc\fR(8).

.

.SH DESCRIPTION (qdisc)

HFSC qdisc has only one optional parameter \- \fBdefault\fR. 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

\fBdefault\fR is not specified, unclassified packets will be dropped.

.

.SH DESCRIPTION (class)

HFSC class is used to create a class hierarchy for HFSC scheduler. For

explanation of the algorithm, and the meaning behind \fBrt\fR, \fBls\fR,

\fBsc\fR and \fBul\fR service curves \- please refer to \fBtc\-hfsc\fR(7).

As you can see in \fBSYNOPSIS\fR, 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, \fBm1\fR is simply

\fBumax\fR/\fBdmax\fR.

Both \fBm2\fR and \fBrate\fR are mandatory. If you omit other

parameters, you will specify linear service curve.

.

.SH "SEE ALSO"

.

\fBtc\fR(8), \fBtc\-hfsc\fR(7), \fBtc\-stab\fR(8)

Please direct bugreports and patches to: <netdev@vger.kernel.org>

.

.SH "AUTHOR"

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Manpage created by Michal Soltys (soltys@ziu.info)