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

       +o at least one of rt, ls or sc must be specified
       +o 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  speci-
       fies  the  minor part of the default classid, where packets not classi-
       fied 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 band-
       width 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: <net...@vger.kernel.org>

AUTHOR
       Manpage created by Michal Soltys (sol...@ziu.info)



iproute2                        31 October 2011                        HFSC(8)