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>