HFSC(8) Linux HFSC(8)
HFSC - Hierarchical Fair Service Curve's control under linux
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).
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.
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.
tc(8), tc-hfsc(7), tc-stab(8) Please direct bugreports and patches to: <firstname.lastname@example.org>
Manpage created by Michal Soltys (email@example.com)
This page is part of the iproute2 (utilities for controlling TCP/IP networking and traffic) project. Information about the project can be found at ⟨http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2⟩. If you have a bug report for this manual page, send it to firstname.lastname@example.org, email@example.com. This page was obtained from the project's upstream Git repository ⟨https://git.kernel.org/pub/scm/network/iproute2/iproute2.git⟩ on 2021-08-27. (At that time, the date of the most recent commit that was found in the repository was 2021-08-18.) If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up-to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which is not part of the original manual page), send a mail to firstname.lastname@example.org iproute2 31 October 2011 HFSC(8)
Pages that refer to this page: tc-hfsc(7), tc(8), tc-stab(8)