[Codel] Codel Digest, Vol 29, Issue 4
kanu monga
kanumonga013 at gmail.com
Sun Feb 22 09:35:08 EST 2015
Thank you so much for replying. i really appreciate it.
i have two more questions:
(1) what is the concept of using TCP/Linux with codel. can't we use other
TCP Variants
(2) N what is purpose of using reverse ftps
On Fri, Feb 20, 2015 at 11:32 PM, <codel-request at lists.bufferbloat.net>
wrote:
> Send Codel mailing list submissions to
> codel at lists.bufferbloat.net
>
> To subscribe or unsubscribe via the World Wide Web, visit
> https://lists.bufferbloat.net/listinfo/codel
> or, via email, send a message with subject or body 'help' to
> codel-request at lists.bufferbloat.net
>
> You can reach the person managing the list at
> codel-owner at lists.bufferbloat.net
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Codel digest..."
>
>
> Today's Topics:
>
> 1. Re: Codel code (Kathleen Nichols)
> 2. Re: Codel code (Dave Taht)
> 3. Setpoint in CoDel (Anjali Chawla)
> 4. Re: Setpoint in CoDel (Dave Taht)
> 5. Re: Setpoint in CoDel (Dave Taht)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Thu, 19 Feb 2015 13:34:14 -0800
> From: Kathleen Nichols <nichols at pollere.com>
> To: codel at lists.bufferbloat.net
> Subject: Re: [Codel] Codel code
> Message-ID: <54E656D6.5010308 at pollere.com>
> Content-Type: text/plain; charset=windows-1252
>
>
> I'll reply list in case anyone else is interested. Just delete if you
> are fortunate enough to
> have nothing to do with ns-2.
>
> First of all, I'm as much a victim of ns-2's tcl as the next person and
> secondly, I will
> tell you what I remember without looking at the c++ code, but would
> recommend
> you take a look at that for some of the settings.
>
> The first commented line just shows how you can set stuff on the command
> line and what
> the different variables are. This particular script is using PackMime to
> generate web
> traffic though there is also an update of a web script I wrote many
> years ago and
> CableLabs paid me to update. I also used that for some codel tests. So
> this can run
> a mix of f ftp connections, w web connections per sec, c constant bit
> rate connections
> through a bottleneck of b Mbps. Use s to set the file size that the ftps
> transfer and if
> set to -1 the ftps are infinite, that is don't terminate over the
> simulation run. This avoids
> lots of slow starts. d is something I used to get the dynamic bandwidth
> thing to work,
> that is it makes the bottleneck link change periodically (you can see
> the plot of this
> in the ACM CoDel paper). Reverse ftps are sourced at the opposite end of
> the bottleneck
> so they create acks in the "forward" direction.
>
> There is a routine called build_cbr and that's where the rate and packet
> size for the CBRs is set. This sets dynamic bw to 0 so the bandwidth
> doesn't change unless set in the command line to do so. I don't remember
> off hand what greedy is. I think it sets one
> ftp to be "greedy".
>
> A bunch of this you should try to figure out for yourself by looking at
> ns2 documentation
> and perhaps at the agent .cc files.
>
> The nominal RTT is what is "expected" and is used as the interval but
> the real rtt is what
> is actually experienced in the particular experiment. I will use this
> opportunity once again
> to note that CoDel is actually more sensitive to this parameter than to
> target in the sense
> that excess drops will happen if the real rtt is longer than the
> interval (I keep trying to
> explain this but no one hears it.)
>
> Code to set the random seed. Sometimes you want different runs to use
> different random
> seeds and sometimes you want to run exactly the same scenario.
>
> There's a bunch of parameters to the TCP agents. Some of these are in
> ns2 documentation,
> but you can find it in the code also.
>
> Just a note that I couldn't get the ns2 TCP/Linux code to work the way
> it was supposed to,
> specifically the idle() routine never seemed to get called. (This sort
> of thing is pretty
> common with ns2) and I didn't want to waste a lot of time untangling the
> tcl-c++
> relationship in ns2. Anyway, so I wrote those tcl procedures to get the
> ftps to restart.
> I wanted to run more modern TCPs, hence use of the Linux TCP.
>
> The dynamic bandwidth thing changes the bandwidth and preset times. It
> does it by multiplying the original bandwidth so I set up an array of
> the mulipliers. I'm sure there's
> a more elegant way to do it but, at this stage of my life, I have
> accepted that I don't do
> elegant. I'm more of a "get the job done" kind of coder. And I really
> don't like ns2 so I
> generally find it works better to just whack it with a hammer rather
> than to try to do
> something beautifully. Note, as above, that a lot of the stuff in ns2
> just doesn't work.
>
> There is code to build up the topology which shouldn't be that hard to
> figure out.
>
> Kathie
>
> On 2/18/15 11:19 PM, kanu monga wrote:
> > is there anyone who can help me in understanding tcl code of codel(given
> > below)
> > This one is quite complex for me.
> > please help if you can.
> > Thanks in advance.
> >
> > ###################################################################
> >
> >
> > # ns codel.tcl f w c {b}Mb s d r
> > # where:
> > #f = # ftps
> > #w = # PackMime connections per second
> > #c = # CBRs
> > #b = bottleneck bandwidth in Mbps
> > #s = filesize for ftp, -1 for infinite
> > #d = dynamic bandwidth, if non-zero, changes (kind of kludgey)
> > #have to set the specific change ratios in this file (below)
> > #r = number of "reverse" ftps
> >
> > set stopTime 300
> > set ns [new Simulator]
> >
> > # These are defaults if values not set on command line
> >
> > set num_ftps 1
> > set web_rate 0
> > set revftp 0
> > set num_cbrs 0
> > #rate and packetSize set in build_cbr
> > set bottleneck 3Mb
> > #for a 10MB ftp
> > set filesize 10000000
> > set dynamic_bw 0
> > set greedy 0
> >
> > # Parse command line
> >
> > if {$argc >= 1} {
> > set num_ftps [lindex $argv 0]
> > if {$argc >= 2} {
> > set web_rate [lindex $argv 1]
> > if {$argc >= 3} {
> > set num_cbrs [lindex $argv 2]
> > if {$argc >= 4} {
> > set bottleneck [lindex $argv 3]
> > if {$argc >= 5} {
> > set filesize [lindex $argv 4]
> > if {$argc >= 6} {
> > set dynamic_bw [lindex $argv 5]
> > if {$argc >= 7} {
> > set revftp [lindex $argv 6]
> > }
> > }
> > }
> > }
> > }
> > }
> > }
> >
> > set bw [bw_parse $bottleneck]
> > if { $revftp >= 1} {
> > set num_revs $revftp
> > } else {
> > set num_revs 0
> > }
> > puts "ftps $num_ftps webrate $web_rate cbrs $num_cbrs bw $bw filesize
> > $filesize reverse $num_revs"
> >
> > # experiment settings
> > set psize 1500
> > if { $bw < 1000000} { set psize 500 }
> > set nominal_rtt [delay_parse 100ms]
> > set accessdly 20
> > set bdelay 10
> > set realrtt [expr 2*(2*$accessdly + $bdelay)]
> > puts "accessdly $accessdly bneckdly $bdelay realrtt $realrtt bneckbw $bw"
> >
> > # CoDel values
> > # interval to keep min over
> > set interval [delay_parse 100ms]
> > # target in ms.
> > set target [delay_parse 5ms]
> >
> > global defaultRNG
> > $defaultRNG seed 0
> > ns-random 0
> > #$defaultRNG seed 54321
> > #ns-random 23145
> >
> > # ------- config info is all above this line ----------
> >
> > #bdp in packets, based on the nominal rtt
> > set bdp [expr round($bw*$nominal_rtt/(8*$psize))]
> >
> > Trace set show_tcphdr_ 1
> > set startTime 0.0
> >
> > #TCP parameters - have to set both for FTPs and PackMime
> >
> > Agent/TCP set window_ [expr $bdp*16]
> > Agent/TCP set segsize_ [expr $psize-40]
> > Agent/TCP set packetSize_ [expr $psize-40]
> > Agent/TCP set windowInit_ 4
> > Agent/TCP set segsperack_ 1
> > Agent/TCP set timestamps_ true
> > set delack 0.4
> > Agent/TCP set interval_ $delack
> >
> > Agent/TCP/FullTcp set window_ [expr $bdp*16]
> > Agent/TCP/FullTcp set segsize_ [expr $psize-40]
> > Agent/TCP/FullTcp set packetSize_ [expr $psize-40]
> > Agent/TCP/FullTcp set windowInit_ 4
> > Agent/TCP/FullTcp set segsperack_ 1
> > Agent/TCP/FullTcp set timestamps_ true
> > Agent/TCP/FullTcp set interval_ $delack
> >
> >
> > Agent/TCP/Linux instproc done {} {
> > global ns filesize
> > #this doesn't seem to work, had to hack tcp-linux.cc to do repeat ftps
> > $self set closed_ 0
> > #needs to be delayed by at least .3sec to slow start
> > puts "[$ns now] TCP/Linux proc done called"
> > $ns at [expr [$ns now] + 0.3] "$self send $filesize"
> > }
> >
> > # problem is that idle() in tcp.cc never seems to get called...
> > Application/FTP instproc resume {} {
> > puts "called resume"
> > global filesize
> > $self send $filesize
> > #$ns at [expr [$ns now] + 0.5] "[$self agent] reset"
> > $ns at [expr [$ns now] + 0.5] "[$self agent] send $filesize"
> > }
> >
> > Application/FTP instproc fire {} {
> > global filesize
> > $self instvar maxpkts_
> > set maxpkts_ $filesize
> > [$self agent] set maxpkts_ $filesize
> > $self send $maxpkts_
> > puts "fire() FTP"
> > }
> >
> > #buffersizes
> > set buffersize [expr $bdp]
> > set buffersize1 [expr $bdp*10]
> >
> > Queue/CoDel set target_ $target
> > Queue/CoDel set interval_ $interval
> >
> > #set Flow_id 1
> >
> > proc build_topology { ns } {
> > # nodes n0 and n1 are the server and client side gateways and
> > # the link between them is the congested slow link. n0 -> n1
> > # handles all the server to client traffic.
> > #
> > # if the web_rate is non-zero, node n2 will be the packmime server
> cloud
> > # and node n3 will be the client cloud.
> > #
> > # num_ftps server nodes and client nodes are created for the ftp
> > sessions.
> > # the first client node is n{2+w} and the first server node is
> n{2+f+w}
> > # where 'f' is num_ftps and 'w' is 1 if web_rate>0 and 0 otherwise.
> > # servers will be even numbered nodes, clients odd
> > # Warning: the numbering here is ridiculously complicated
> >
> > global bw bdelay accessdly buffersize buffersize1 filesize node_cnt
> > set node_cnt 2
> >
> > # congested link
> > global n0 n1
> > set n0 [$ns node]
> > set n1 [$ns node]
> > $ns duplex-link $n0 $n1 $bw ${bdelay}ms CoDel
> > $ns duplex-link-op $n0 $n1 orient right
> > $ns duplex-link-op $n0 $n1 queuePos 0.5
> > $ns duplex-link-op $n1 $n0 queuePos 1.5
> > $ns queue-limit $n0 $n1 $buffersize
> > $ns queue-limit $n1 $n0 $buffersize
> > set node_cnt 2
> >
> > #dynamic bandwidth
> > # these are the multipliers for changing bw, times initial set bw
> > # edit these values to get different patterns
> > global stopTime dynamic_bw
> > array names bw_changes
> > set bw_changes(1) 0.1
> > set bw_changes(2) 0.01
> > set bw_changes(3) 0.5
> > set bw_changes(4) 0.01
> > set bw_changes(5) 1.0
> >
> > puts "bottleneck starts at [[[$ns link $n0 $n1] link] set
> > bandwidth_]bps"
> > for {set k 1} {$k <= $dynamic_bw} {incr k 1} {
> > set changeTime [expr $k*$stopTime/($dynamic_bw+1)]
> > set f $bw_changes($k)
> > set newBW [expr $f*$bw]
> > puts "change at $changeTime to [expr $newBW/1000000.]Mbps"
> > $ns at $changeTime "[[$ns link $n0 $n1] link] set bandwidth_ $newBW"
> > $ns at $changeTime "[[$ns link $n1 $n0] link] set bandwidth_ $newBW"
> > $ns at $changeTime "puts $newBW"
> > }
> >
> > set li_10 [[$ns link $n1 $n0] queue]
> > set li_01 [[$ns link $n0 $n1] queue]
> >
> > set tchan_ [open /tmp/redqvar.tr <http://redqvar.tr> w]
> > $li_01 trace curq_
> > $li_01 trace d_exp_
> > $li_01 attach $tchan_
> >
> > global num_ftps web_rate num_cbrs greedy num_revs
> > set linkbw [expr $bw*10]
> >
> > set w [expr $web_rate > 0]
> > if {$w} {
> > global n2 n3
> > #server
> > set n2 [$ns node]
> > $ns duplex-link $n2 $n0 $linkbw ${accessdly}ms DropTail
> > $ns queue-limit $n2 $n0 $buffersize1
> > $ns queue-limit $n0 $n2 $buffersize1
> >
> > #client
> > set n3 [$ns node]
> > $ns duplex-link $n1 $n3 $linkbw ${accessdly}ms DropTail
> > $ns queue-limit $n1 $n3 $buffersize1
> > $ns queue-limit $n3 $n1 $buffersize1
> > set node_cnt 4
> > }
> > #need to fix the angles if use nam
> > for {set k 0} {$k < $num_ftps} {incr k 1} {
> > # servers
> > set j $node_cnt
> > global n$j
> > set n$j [$ns node]
> > if {$greedy > 0 && $k == 0} {
> > $ns duplex-link [set n$j] $n0 $linkbw 1ms DropTail
> > } else {
> > $ns duplex-link [set n$j] $n0 $linkbw ${accessdly}ms DropTail
> > }
> > $ns queue-limit [set n$j] $n0 $buffersize1
> > $ns queue-limit $n0 [set n$j] $buffersize1
> > set angle [expr $num_ftps>1? 0.75+($k-1)*.5/($num_ftps-1) : 1]
> > $ns duplex-link-op $n0 [set n$j] orient $angle
> > incr node_cnt
> >
> > # clients
> > set j $node_cnt
> > global n$j
> > set n$j [$ns node]
> > set dly [expr ${accessdly} +($k+1)]
> > $ns duplex-link $n1 [set n$j] $linkbw ${dly}ms DropTail
> > $ns queue-limit $n1 [set n$j] $buffersize1
> > $ns queue-limit [set n$j] $n1 $buffersize1
> > set angle [expr $num_ftps>1? fmod(2.25-($k-1)*.5/($num_ftps-1),
> > 2) : 0]
> > $ns duplex-link-op $n1 [set n$j] orient $angle
> > incr node_cnt
> > }
> > for {set k 0} {$k < $num_cbrs} {incr k 1} {
> > # servers
> > set j $node_cnt
> > global n$j
> > set n$j [$ns node]
> > $ns duplex-link [set n$j] $n0 $linkbw ${accessdly}ms DropTail
> > $ns queue-limit [set n$j] $n0 $buffersize1
> > $ns queue-limit $n0 [set n$j] $buffersize1
> > # set angle [expr $num_cbrs>1? 0.75+($k-1)*.5/($num_cbrs-1) : 1]
> > $ns duplex-link-op $n0 [set n$j] orient $angle
> > incr node_cnt
> >
> > # clients
> > set j $node_cnt
> > global n$j
> > set n$j [$ns node]
> > $ns duplex-link $n1 [set n$j] $linkbw ${accessdly}ms DropTail
> > $ns queue-limit $n1 [set n$j] $buffersize1
> > $ns queue-limit [set n$j] $n1 $buffersize1
> > # set angle [expr $num_cbrs>1? fmod(2.25-($k-1)*.5/($num_ftps-1),
> > 2) : 0]
> > $ns duplex-link-op $n1 [set n$j] orient $angle
> > incr node_cnt
> > }
> > #reverse direction ftps
> > for {set k 0} {$k < $num_revs} {incr k 1} {
> > # clients
> > set j $node_cnt
> > global n$j
> > set n$j [$ns node]
> > $ns duplex-link [set n$j] $n0 $linkbw ${accessdly}ms DropTail
> > $ns queue-limit [set n$j] $n0 $buffersize1
> > $ns queue-limit $n0 [set n$j] $buffersize1
> > set angle [expr $num_ftps>1? 0.75+($k-1)*.5/($num_ftps-1) : 1]
> > $ns duplex-link-op $n0 [set n$j] orient $angle
> > incr node_cnt
> >
> > # servers
> > set j $node_cnt
> > global n$j
> > set n$j [$ns node]
> > set dly [expr ($accessdly)*1.1 +($k+1)]
> > $ns duplex-link $n1 [set n$j] $linkbw ${dly}ms DropTail
> > $ns queue-limit $n1 [set n$j] $buffersize1
> > $ns queue-limit [set n$j] $n1 $buffersize1
> > set angle [expr $num_ftps>1? fmod(2.25-($k-1)*.5/($num_ftps-1),
> > 2) : 0]
> > $ns duplex-link-op $n1 [set n$j] orient $angle
> > incr node_cnt
> > }
> > }
> >
> > proc build_cbr {cnd snd startTime timeToStop Flow_id} {
> > global ns
> > set udp [$ns create-connection UDP $snd LossMonitor $cnd $Flow_id]
> > set cbr [new Application/Traffic/CBR]
> > $cbr attach-agent $udp
> > # change these for different types of CBRs
> > $cbr set packetSize_ 100
> > $cbr set rate_ 0.064Mb
> > $ns at $startTime "$cbr start"
> > $ns at $timeToStop "$cbr stop"
> > }
> >
> > # cnd is client node, snd is server node
> > proc build_ftpclient {cnd snd startTime timeToStop Flow_id} {
> >
> > global ns filesize greedy revftp
> > set ctcp [$ns create-connection TCP/Linux $snd TCPSink/Sack1 $cnd
> > $Flow_id]
> > $ctcp select_ca cubic
> > set ftp [$ctcp attach-app FTP]
> > $ftp set enableResume_ true
> > $ftp set type_ FTP
> >
> > #set up a single infinite ftp with smallest RTT
> > if {$greedy > 0 || $filesize < 0} {
> > $ns at $startTime "$ftp start"
> > set greedy 0
> > } else {
> > $ns at $startTime "$ftp send $filesize"
> > }
> > $ns at $timeToStop "$ftp stop"
> > }
> >
> > proc build_webs {cnd snd rate startTime timeToStop} {
> > set CLIENT 0
> > set SERVER 1
> >
> > # SETUP PACKMIME
> > set pm [new PackMimeHTTP]
> > $pm set-TCP Sack
> > $pm set-client $cnd
> > $pm set-server $snd
> > $pm set-rate $rate; # new connections per second
> > $pm set-http-1.1; # use HTTP/1.1
> >
> > # create RandomVariables
> > set flow_arrive [new RandomVariable/PackMimeHTTPFlowArrive $rate]
> > set req_size [new RandomVariable/PackMimeHTTPFileSize $rate $CLIENT]
> > set rsp_size [new RandomVariable/PackMimeHTTPFileSize $rate $SERVER]
> >
> > # assign RNGs to RandomVariables
> > $flow_arrive use-rng [new RNG]
> > $req_size use-rng [new RNG]
> > $rsp_size use-rng [new RNG]
> >
> > # set PackMime variables
> > $pm set-flow_arrive $flow_arrive
> > $pm set-req_size $req_size
> > $pm set-rsp_size $rsp_size
> >
> > global ns
> > $ns at $startTime "$pm start"
> > $ns at $timeToStop "$pm stop"
> > }
> >
> > proc uniform {a b} {
> > expr $a + (($b- $a) * ([ns-random]*1.0/0x7fffffff))
> > }
> >
> > proc finish {} {
> > global ns
> > $ns halt
> > $ns flush-trace
> > exit 0
> > }
> >
> > # $ns namtrace-all [open out.nam w]
> > # $ns color 2 blue
> > # $ns color 3 red
> > # $ns color 4 yellow
> > # $ns color 5 green
> >
> > build_topology $ns
> >
> > #$ns trace-queue $n0 $n1 [open out_n0ton1.tr <http://out_n0ton1.tr> w]
> > #set fname f${num_ftps}w${web_rate}b${bottleneck}.tr
> > set fname f.tr <http://f.tr>
> > puts $fname
> > $ns trace-queue $n0 $n1 [open /tmp/$fname w]
> > #reverse direction
> > #$ns trace-queue $n1 $n0 [open /tmp/$fname w]
> >
> > set node_cnt 2
> > if {$web_rate > 0} {
> > build_webs $n3 $n2 $web_rate 0 $stopTime
> > set node_cnt 4
> > }
> >
> > for {set k 1} {$k <= $num_ftps} {incr k 1} {
> > set j $node_cnt
> > incr node_cnt
> > set i $node_cnt
> > build_ftpclient [set n$i] [set n$j] \
> > $startTime $stopTime $i
> > # [expr 1.0*($k-1)] $stopTime $i
> > # [expr $startTime+($k-1)*[uniform 0.0 2.0]] $stopTime $i
> > incr node_cnt
> > }
> >
> > for {set k 1} {$k <= $num_cbrs} {incr k 1} {
> > set j $node_cnt
> > incr node_cnt
> > set i $node_cnt
> > build_cbr [set n$i] [set n$j] \
> > [expr $startTime+($k-1)*[uniform 0.0 2.0]] $stopTime $i
> > incr node_cnt
> > }
> >
> > #for reverse direction, give client smaller number
> > for {set k 1} {$k <= $num_revs} {incr k 1} {
> > set j $node_cnt
> > incr node_cnt
> > set i $node_cnt
> > build_ftpclient [set n$j] [set n$i] $startTime $stopTime $j
> > incr node_cnt
> > }
> >
> > $ns at [expr $stopTime ] "finish"
> > $ns run
> > exit 0
> > ###################################################################
> >
> >
> > _______________________________________________
> > Codel mailing list
> > Codel at lists.bufferbloat.net
> > https://lists.bufferbloat.net/listinfo/codel
> >
>
>
>
> ------------------------------
>
> Message: 2
> Date: Thu, 19 Feb 2015 13:38:53 -0800
> From: Dave Taht <dave.taht at gmail.com>
> To: Kathleen Nichols <nichols at pollere.com>
> Cc: "codel at lists.bufferbloat.net" <codel at lists.bufferbloat.net>
> Subject: Re: [Codel] Codel code
> Message-ID:
> <CAA93jw5dWzXfEX70w1PFmPudH+qfurq=
> e4Srbth2+f4QC2h4Og at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> I am fairly happy with the example codel code that is now in the ns3
> branch,
> which is pure c++, and quite a bit easier to understand than tcl, to my
> eye.
>
> https://www.nsnam.org/doxygen/codel-vs-droptail-asymmetric_8cc.html
>
> regrettably the fq_codel version for ns3 is still out of tree.
>
>
> ------------------------------
>
> Message: 3
> Date: Fri, 20 Feb 2015 00:46:11 -0800
> From: Anjali Chawla <anjaliachawla013 at gmail.com>
> To: codel at lists.bufferbloat.net
> Subject: [Codel] Setpoint in CoDel
> Message-ID:
> <CAL6QuG8ktPQgrGkA+wp9V=
> BHqdcQh4E19dsX02Pozh_fjfJ+0w at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Hi
> anyone please explain me what is concept behind setpoint in codel
> algorithm??
> Thanks
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <
> https://lists.bufferbloat.net/pipermail/codel/attachments/20150220/285d07dd/attachment-0001.html
> >
>
> ------------------------------
>
> Message: 4
> Date: Fri, 20 Feb 2015 01:21:13 -0800
> From: Dave Taht <dave.taht at gmail.com>
> To: Anjali Chawla <anjaliachawla013 at gmail.com>
> Cc: "codel at lists.bufferbloat.net" <codel at lists.bufferbloat.net>
> Subject: Re: [Codel] Setpoint in CoDel
> Message-ID:
> <
> CAA93jw43TJdo9FK61HK0et3Mopq8-YKjjkNm_6_OF7+g0iMipw at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> the best talk on the subject was van?s at ietf, it is well worth
> watching multiple times.
>
> http://www.bufferbloat.net/projects/cerowrt/wiki/Bloat-videos
>
> He goes deeply into the reasoning behind the sojourn time, and setpoint.
>
> About the only other somewhat in-depth talk on how codel really works
> was my attempt at stanford.
>
> and there are of course other talks above that try to describe bits of
> the elephant.
>
> One of these days I hope someone puts together the definitive talk on
> codel complete with even more elegant demos than stephen hemminger
> came up with..., but it does seem to be really hard for people to get
> at a deep level... most of my own talks are more about fq than
> fq_codel, and that is *tons* easier to explain.
>
> If you watch them all a bunch of times, and run a few experiments of
> your own, enlightenment will come. For me, it was seeing kathie give
> the first public explanation of codel - about midway through I started
> vibrating in my seat - but I had just completed a slash and burn tour
> through all the aqm literature going back 30 years, and trying
> everything that seemed to make sense. I don?t know how to impart that
> in an email...
>
>
> On Fri, Feb 20, 2015 at 12:46 AM, Anjali Chawla
> <anjaliachawla013 at gmail.com> wrote:
> > Hi
> > anyone please explain me what is concept behind setpoint in codel
> > algorithm??
> > Thanks
> >
> > _______________________________________________
> > Codel mailing list
> > Codel at lists.bufferbloat.net
> > https://lists.bufferbloat.net/listinfo/codel
> >
>
>
>
> --
> Dave T?ht
>
> thttp://www.bufferbloat.net/projects/bloat/wiki/Upcoming_Talks
>
>
> ------------------------------
>
> Message: 5
> Date: Fri, 20 Feb 2015 10:01:54 -0800
> From: Dave Taht <dave.taht at gmail.com>
> To: Anjali Chawla <anjaliachawla013 at gmail.com>
> Cc: "codel at lists.bufferbloat.net" <codel at lists.bufferbloat.net>
> Subject: Re: [Codel] Setpoint in CoDel
> Message-ID:
> <CAA93jw7147Ucy=
> fRmt-65VuUSDyVwHwH9NCmOFjq4GULYGC63A at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> On Fri, Feb 20, 2015 at 1:21 AM, Dave Taht <dave.taht at gmail.com> wrote:
> > the best talk on the subject was van?s at ietf, it is well worth
> > watching multiple times.
> >
> > http://www.bufferbloat.net/projects/cerowrt/wiki/Bloat-videos
> >
> > He goes deeply into the reasoning behind the sojourn time, and setpoint.
> >
> > About the only other somewhat in-depth talk on how codel really works
> > was my attempt at stanford.
>
> The stanford talk took some digging to find. I would really like a shot
> at a do-over one day - or for van to give his talk again to be filmed at
> high quality.
>
> https://www.youtube.com/watch?v=Mxoa5Si4Ubw
>
> >
> > and there are of course other talks above that try to describe bits of
> > the elephant.
> >
> > One of these days I hope someone puts together the definitive talk on
> > codel complete with even more elegant demos than stephen hemminger
> > came up with..., but it does seem to be really hard for people to get
> > at a deep level... most of my own talks are more about fq than
> > fq_codel, and that is *tons* easier to explain.
> >
> > If you watch them all a bunch of times, and run a few experiments of
> > your own, enlightenment will come. For me, it was seeing kathie give
> > the first public explanation of codel - about midway through I started
> > vibrating in my seat - but I had just completed a slash and burn tour
> > through all the aqm literature going back 30 years, and trying
> > everything that seemed to make sense. I don?t know how to impart that
> > in an email...
> >
> >
> > On Fri, Feb 20, 2015 at 12:46 AM, Anjali Chawla
> > <anjaliachawla013 at gmail.com> wrote:
> >> Hi
> >> anyone please explain me what is concept behind setpoint in codel
> >> algorithm??
> >> Thanks
> >>
> >> _______________________________________________
> >> Codel mailing list
> >> Codel at lists.bufferbloat.net
> >> https://lists.bufferbloat.net/listinfo/codel
> >>
> >
> >
> >
> > --
> > Dave T?ht
> >
> > thttp://www.bufferbloat.net/projects/bloat/wiki/Upcoming_Talks
>
>
>
> --
> Dave T?ht
>
> thttp://www.bufferbloat.net/projects/bloat/wiki/Upcoming_Talks
>
>
> ------------------------------
>
> _______________________________________________
> Codel mailing list
> Codel at lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/codel
>
>
> End of Codel Digest, Vol 29, Issue 4
> ************************************
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.bufferbloat.net/pipermail/codel/attachments/20150222/278bf4b8/attachment-0002.html>
More information about the Codel
mailing list