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,  CLAS‐
       SIFY target of iptables) will be enqueued. If default is not specified, unclassified pack‐
       ets 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 ser‐
       vice curve.

SEE ALSO
       tc(8), tc-hfsc(7), tc-stab(8)

       Please direct bugreports and patches to: <net... AT vger.org>

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



iproute2                                 31 October 2011                                  HFSC(8)