DCB-ETS(8)			     Linux			    DCB-ETS(8)

NAME
       dcb-ets - show / manipulate ETS (Enhanced Transmission Selection)
       settings of the DCB (Data Center Bridging) subsystem

SYNOPSIS

       dcb [ OPTIONS ]	ets { COMMAND | help }


       dcb ets show dev DEV [ willing ] [ ets-cap ] [ cbs ] [ tc-tsa ] [
	       reco-tc-tsa ] [ pg-bw ] [ tc-bw ] [ reco-tc-bw ] [ prio-tc ] [
	       reco-prio-tc ]

       dcb ets set dev DEV [ willing { on | off } ] [ { tc-tsa | reco-tc-tsa }
	       TSA-MAP ] [ { pg-bw | tc-bw | reco-tc-bw } BW-MAP ] [ { prio-tc
	       | reco-prio-tc } PRIO-MAP ]

       TSA-MAP := [ TSA-MAP ] TSA-MAPPING

       TSA-MAPPING := { TC | all }:{ strict |  cbs | ets | vendor }

       BW-MAP := [ BW-MAP ] BW-MAPPING

       BW-MAPPING := { TC | all }:INTEGER

       PRIO-MAP := [ PRIO-MAP ] PRIO-MAPPING

       PRIO-MAPPING := { PRIO | all }:TC

       TC := { 0 .. 7 }

       PRIO := { 0 .. 7 }


DESCRIPTION
       dcb ets is used to configure Enhanced Transmission Selection attributes
       through Linux DCB (Data Center Bridging) interface. ETS permits
       configuration of mapping of priorities to traffic classes, traffic
       selection algorithm to use per traffic class, bandwidth allocation,
       etc.

       Two DCB TLVs are related to the ETS feature: a configuration and
       recommendation values. Recommendation values are named with a prefix
       reco-, while the configuration ones have plain names.


PARAMETERS
       For read-write parameters, the following describes only the write
       direction, i.e. as used with the set command. For the show command, the
       parameter name is to be used as a simple keyword without further
       arguments. This instructs the tool to show the value of a given
       parameter. When no parameters are given, the tool shows the complete
       ETS configuration.


       ets-cap
	      A read-only property that shows the number of supported ETS
	      traffic classes.


       cbs    A read-only property that is enabled if the driver and the
	      hardware support the CBS Transmission Selection Algorithm.


       willing { on | off }
	      Whether local host should accept configuration from peer TLVs.


       prio-tc PRIO-MAP
       reco-prio-tc PRIO-MAP
	      PRIO-MAP uses the array parameter syntax, see dcb(8) for
	      details. Keys are priorities, values are traffic classes. For
	      each priority sets a TC where traffic with that priority is
	      directed to.


       tc-tsa TSA-MAP
       reco-tc-tsa TSA-MAP
	      TSA-MAP uses the array parameter syntax, see dcb(8) for details.
	      Keys are TCs, values are Transmission Selection Algorithm (TSA)
	      keywords described below. For each TC sets an algorithm used for
	      deciding how traffic queued up at this TC is scheduled for
	      transmission. Supported TSAs are:

	      strict - for strict priority, where traffic in higher-numbered
	      TCs always takes precedence over traffic in lower-numbered TCs.
	      ets - for Enhanced Traffic Selection, where available bandwidth
	      is distributed among the ETS-enabled TCs according to the
	      weights set by tc-bw and reco-tc-bw, respectively.
	      cbs - for Credit Based Shaper, where traffic is scheduled in a
	      strict manner up to the limit set by a shaper.
	      vendor - for vendor-specific traffic selection algorithm.


       tc-bw BW-MAP
       reco-tc-bw BW-MAP
	      BW-MAP uses the array parameter syntax, see dcb(8) for details.
	      Keys are TCs, values are integers representing percent of
	      available bandwidth given to the traffic class in question. The
	      value should be 0 for TCs whose TSA is not ets, and the sum of
	      all values shall be 100. As an exception to the standard
	      wording, a configuration with no ets TCs is permitted to sum up
	      to 0 instead.


       pg-bw BW-MAP
	      The precise meaning of pg-bw is not standardized, but the
	      assumption seems to be that the same scheduling process as on
	      the transmit side is applicable on receive side as well, and
	      configures receive bandwidth allocation for ets ingress traffic
	      classes (priority groups).


EXAMPLE & USAGE
       Configure ETS priomap in a one-to-one fashion:


       # dcb ets set dev eth0 prio-tc 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7

       Set TSA and transmit bandwidth configuration:


       # dcb ets set dev eth0 tc-tsa all:strict 0:ets 1:ets 2:ets \
			      tc-bw all:0 0:33 1:33 2:34

       Show what was set:


       # dcb ets show dev eth0 prio-tc tc-tsa tc-bw
       prio-tc 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
       tc-tsa 0:ets 1:ets 2:ets 3:strict 4:strict 5:strict 6:strict 7:strict
       tc-bw 0:33 1:33 2:34 3:0 4:0 5:0 6:0 7:0


EXIT STATUS
       Exit status is 0 if command was successful or a positive integer upon
       failure.


SEE ALSO
       dcb(8)


REPORTING BUGS
       Report any bugs to the Network Developers mailing list
       <netdev@vger.kernel.org> where the development and maintenance is
       primarily done.	You do not have to be subscribed to the list to send a
       message there.


AUTHOR
       Petr Machata <me@pmachata.org>

iproute2			19 October 2020			    DCB-ETS(8)