From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-x22e.google.com (mail-wm0-x22e.google.com [IPv6:2a00:1450:400c:c09::22e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 79E153B2A3 for ; Fri, 28 Apr 2017 15:03:17 -0400 (EDT) Received: by mail-wm0-x22e.google.com with SMTP id m123so54998672wma.0 for ; Fri, 28 Apr 2017 12:03:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:from:subject:message-id:date:user-agent:mime-version :content-transfer-encoding; bh=3D70dzmabwDivhIlhnpJovR/hyttFxvO+IIwlPwJUdY=; b=YNJwCu4H1EoWgZ2ppXSecxMHsUu04qVCDPeiiCzeHxQBSa068VBtcUbY5t5p9/VYd4 jGX0JlpF2iTXMij3Y/c8jGQ26KTL1MxcBjWg93parKdA5dHmWVabL9pePyqWapbEL/JG BWDOfqMrvakujAMHTs838YdeEUorzAGmGUbsJIju/bTe7UD+N8AY4NRTek5x6R/MFTOL smSIMQPTcM9uCLWWqAeKG/KD0xStgI27JluhqCU5AE65d6iw+aQK3oSzDquqsFxpSGqv /8zVoQngg7lpJTytARp694DYPgpOQ4bNN6XumrNVflg6JbURKEQ8oavqo7Zou4X9RzPV sgCw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:from:subject:message-id:date:user-agent :mime-version:content-transfer-encoding; bh=3D70dzmabwDivhIlhnpJovR/hyttFxvO+IIwlPwJUdY=; b=a4SR5be4FQ8i1pfCTMj1/y6NyARX1i27//iayDZQNZ2TtuOB66BTgGkLgJQ6A1c0AI 5lX6+GFfPJWVrUjtAUcIEXK7ka6HnxQWByA+2/GqGugiIMVos/aH77UqKNwBVKEjY+Mn 92OXA7xwiyDuQxLNEWBap8yn7VCPChn2rfC08qnoFqc5Jb5lztbepYODA+yFzFFNCJgH /JWWhchcOEXtyysZ1OdGd1lOUCjDgDKfmJrwJPRYRnxPEfoWpZHrACheu+MEcu9fqPEG fyaaF9cPOZe9hLu7kzz9hvPjERfo0++9cP8Cr0jbbFUfviVp58isRyaqCs5bLQB6x/fc 55Eg== X-Gm-Message-State: AN3rC/4z+IXWMqq03h0rq2RFv3eiGzUZxyL0nYbqR1I3y5AqMuV9IPcN iTO728G6n2t6ui0v X-Received: by 10.28.220.215 with SMTP id t206mr7036755wmg.119.1493406196075; Fri, 28 Apr 2017 12:03:16 -0700 (PDT) Received: from [192.168.0.3] (185.182.7.51.dyn.plus.net. [51.7.182.185]) by smtp.gmail.com with ESMTPSA id 2sm354818wmk.20.2017.04.28.12.03.14 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 28 Apr 2017 12:03:15 -0700 (PDT) To: Cake@lists.bufferbloat.net From: Andy Furniss Subject: cake default target is too low for bbr? Message-ID: <7fefc8ad-33e6-cf65-2f90-f71dd2651ee3@gmail.com> Date: Fri, 28 Apr 2017 20:03:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:54.0) Gecko/20100101 Firefox/54.0 SeaMonkey/2.51a2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-List-Received-Date: Fri, 28 Apr 2017 19:03:17 -0000 Motivated by an observation about steam downloads in the thread Getting Cake to work better with Steam and similar applications I set up a test - maybe not the best test ever but interesting results. Put cake on ifb on PC with netem also on egress/ingress adding 4ms each way (that's how close I am to steam). Pretend I have 16mbit atm, though here it's shaped on egress and I am sending 5 connections 10 sec with netperf and bbr enabled. This doesn't happen with cubic. OK so ecn may cure - but people may no know how or want that on. This issue is that there are a lot of drops causing someone with a highly asymmetric line to possibly use all upload as (s)ack per packet is prevalent due to excessive drops. Here's some pastes same test with target varied (via rtt param) The 5 connections are from different src ips. qdisc cake 1: dev ifb0 root refcnt 2 bandwidth 16Mbit diffserv3 dual-srchost rtt 100.0ms atm overhead 40 via-ethernet Sent 17477050 bytes 11597 pkt (dropped 8476, overlimits 31565 requeues 0) backlog 0b 0p requeues 0 memory used: 144Kb of 4Mb capacity estimate: 16Mbit Bulk Best Effort Voice thresh 1Mbit 16Mbit 4Mbit target 18.2ms 5.0ms 5.0ms interval 113.2ms 100.0ms 10.0ms pk_delay 0us 6.9ms 0us av_delay 0us 4.6ms 0us sp_delay 0us 5us 0us pkts 0 20073 0 bytes 0 30307578 0 way_inds 0 0 0 way_miss 0 10 0 way_cols 0 0 0 drops 0 8476 0 marks 0 0 0 sp_flows 0 5 0 bk_flows 0 1 0 un_flows 0 0 0 max_len 0 1514 0 qdisc cake 1: dev ifb0 root refcnt 2 bandwidth 16Mbit diffserv3 dual-srchost rtt 200.0ms atm overhead 40 via-ethernet Sent 17459144 bytes 11584 pkt (dropped 3277, overlimits 26349 requeues 0) backlog 0b 0p requeues 0 memory used: 161280b of 4Mb capacity estimate: 16Mbit Bulk Best Effort Voice thresh 1Mbit 16Mbit 4Mbit target 18.2ms 10.0ms 10.0ms interval 208.2ms 200.0ms 20.0ms pk_delay 0us 12.7ms 0us av_delay 0us 10.3ms 0us sp_delay 0us 11us 0us pkts 0 14861 0 bytes 0 22420426 0 way_inds 0 0 0 way_miss 0 10 0 way_cols 0 0 0 drops 0 3277 0 marks 0 0 0 sp_flows 0 5 0 bk_flows 0 1 0 un_flows 0 0 0 max_len 0 1514 0 qdisc cake 1: dev ifb0 root refcnt 2 bandwidth 16Mbit diffserv3 dual-srchost rtt 300.0ms atm overhead 40 via-ethernet Sent 17613408 bytes 11680 pkt (dropped 1574, overlimits 24849 requeues 0) backlog 0b 0p requeues 0 memory used: 171Kb of 4Mb capacity estimate: 16Mbit Bulk Best Effort Voice thresh 1Mbit 16Mbit 4Mbit target 18.2ms 15.0ms 15.0ms interval 303.2ms 300.0ms 30.0ms pk_delay 0us 13.6ms 0us av_delay 0us 12.1ms 0us sp_delay 0us 14us 0us pkts 0 13254 0 bytes 0 19996444 0 way_inds 0 0 0 way_miss 0 10 0 way_cols 0 0 0 drops 0 1574 0 marks 0 0 0 sp_flows 0 5 0 bk_flows 0 1 0 un_flows 0 0 0 max_len 0 1514 0 qdisc cake 1: dev ifb0 root refcnt 2 bandwidth 16Mbit diffserv3 dual-srchost rtt 400.0ms atm overhead 40 via-ethernet Sent 17674640 bytes 11720 pkt (dropped 920, overlimits 24270 requeues 0) backlog 0b 0p requeues 0 memory used: 186624b of 4Mb capacity estimate: 16Mbit Bulk Best Effort Voice thresh 1Mbit 16Mbit 4Mbit target 20.0ms 20.0ms 20.0ms interval 400.0ms 400.0ms 40.0ms pk_delay 0us 16.8ms 0us av_delay 0us 16.2ms 0us sp_delay 0us 17us 0us pkts 0 12640 0 bytes 0 19067520 0 way_inds 0 0 0 way_miss 0 10 0 way_cols 0 0 0 drops 0 920 0 marks 0 0 0 sp_flows 0 5 0 bk_flows 0 1 0 un_flows 0 0 0 max_len 0 1514 0 qdisc cake 1: dev ifb0 root refcnt 2 bandwidth 16Mbit diffserv3 dual-srchost rtt 500.0ms atm overhead 40 via-ethernet Sent 17614080 bytes 11680 pkt (dropped 613, overlimits 23885 requeues 0) backlog 0b 0p requeues 0 memory used: 186624b of 4Mb capacity estimate: 16Mbit Bulk Best Effort Voice thresh 1Mbit 16Mbit 4Mbit target 25.0ms 25.0ms 25.0ms interval 500.0ms 500.0ms 50.0ms pk_delay 0us 18.6ms 0us av_delay 0us 17.1ms 0us sp_delay 0us 19us 0us pkts 0 12293 0 bytes 0 18542162 0 way_inds 0 0 0 way_miss 0 10 0 way_cols 0 0 0 drops 0 613 0 marks 0 0 0 sp_flows 0 5 0 bk_flows 0 1 0 un_flows 0 0 0 max_len 0 1514 0