From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 996513B29D for ; Sat, 9 Mar 2024 16:01:19 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.de; s=s31663417; t=1710018074; x=1710622874; i=moeller0@gmx.de; bh=co9eH0tTJ8HM9/gk4RjEwc+kFuSOJx20Uohyo7Xy5rE=; h=X-UI-Sender-Class:Subject:From:In-Reply-To:Date:Cc:References: To; b=TCJ1CkysSJ70YCWpfKiubIDO6+0aQENIqhw49nmVf5ia3tCM/fK+2M5REGnMyrwg iKLBCifQLKuEd3V8+xZmKUMgOPODZr/9peWb9Yq/lyrxf1U1iArqBPvgSYOtVnRRm 2vUsXzVlEWO05cJdA1n2qL5b6BRKm4VamasCexMuiDSG1CTpAcLrciw9xWYaxkuhd kdIhheTZWOSwbZJYHr8+7u70jsm/knAMXpSA+EZxipP7U1daVDt5KxkSLfVBSwcmB p6VO/CSMriODFtz9H6jMJfAm7XmjnMUXyHqqza5//iGrcrgYib64NGOjOa8nJZ3UR kwyyYzRn8rgADUhIkA== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from smtpclient.apple ([95.116.69.241]) by mail.gmx.net (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1My32F-1qtzE504id-00zX4c; Sat, 09 Mar 2024 22:01:14 +0100 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3774.500.171.1.1\)) From: Sebastian Moeller In-Reply-To: <917dd3641c98e29c1d259aa32f1c2414@rjmcmahon.com> Date: Sat, 9 Mar 2024 22:01:03 +0100 Cc: rjmcmahon , "Douglas Goncz A.A.S. M.E.T. 1990" Content-Transfer-Encoding: quoted-printable Message-Id: References: <8op80p47-77p9-p9s3-6o32-7s93o3ssp653@ynat.uz> <636F01F7-54FB-41A6-957F-99D114A72B6A@comcast.com> <917dd3641c98e29c1d259aa32f1c2414@rjmcmahon.com> To: =?utf-8?Q?Network_Neutrality_is_back!_Let=C2=B4s_make_the_technical_as?= =?utf-8?Q?pects_heard_this_time!?= X-Mailer: Apple Mail (2.3774.500.171.1.1) X-Provags-ID: V03:K1:gyvBt6F+kaqOum/lRoS49NmkIZR/aLpj38GNl/KH1Jw6JfShNmN TTW5NNSBiDEhLT4tvvdKNq4hFWYmIlD0KzOWc7qXZKsWEXjEuQMxhZsuCj5caB4HCeWxbaW U+6+EZNTqg5jVIPQsedSmP3WHV14hidm0JZf8XjjsDoH/VlweDLffop/p7TzKr4DLOzVflV Xa5a4nnB1qn+urch1PvWQ== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:Bsc5TGQmBYM=;oSkXk3g2Q86KaX+hedNR4RIKexB Csg830XIFOz/fU88WYtamnfRD5lXdDIJ/9XqUkXVmdY2FjzrDU6W2Z/k4z9taEQhsLJPfu26f j+rwFSgmX7dL8Wh7nFVceJD3yzCfeNJmYHteTdS5ihsFgDjlj3ZcRx2x/ISfywsXpb2bnrtm7 6GK2K4Sds9wHQM9gsULYDXvxcqlsAVwhakMrv+YA/1NL0H21rWZyi41umF5ju6IS3b+jUPYnR tD2H1si/RTwsdsZOE2J6ySJr2aM76s/Xm9WCvGjBuast2Aa57Y4i2vf9jnR1cT4EGUgzFZIrd TdFQNp1287OFQKeZ01n99mINOBBWET+sQjpi8ANG2Je5vNJsGG3tKq2HP9aSLXyE7/6HfmSTv WKGlkl+FUZIr0hONlcsEObt4Wl1XSkrcFFQN92Sp3LT2aeAGeDhMZcjN/3LwgsbbsNVfpgk7Y DUn/5vB3xizahkNGvFH+wUZj+gA/VTBHdZoMsaYrvT4i8ZK8AdA6KBgxQEN3WXmlaFETxuoIf G/NLQGK+KuZkCWclDmL64LoYXD7L++Z9psIE5QVwfOiz3lH3MzegJsM5X1/G7a4GVQ4YgjJjI qQc3OIKWZ5sd/X9Ns7Dq6ehMz3Z2piNsW7uUhxyWPJ3NAz9eBWpU+je09GtRANbWtUo1bwAzr tLPQKGGcyZOuI1gT72vZQ0TUd53nxgLoTLXrBJuvZ3Nwbq83d8NioM6AHD8CaFdzW3EZPtl0Q 8gVfgcRMsghlYJ1Yix+71JaK53ZL9EyQWhNr/VjMjqDvvYJILxq7e9XCccyERcOYUbHyp1DeZ Daw3nIX6TtEAU9L/1A2bOv4AIG0L7aW1B3komVhJGr0gk= Subject: Re: [NNagain] Flash priority X-BeenThere: nnagain@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: =?utf-8?q?Network_Neutrality_is_back!_Let=C2=B4s_make_the_technical_aspects_heard_this_time!?= List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 Mar 2024 21:01:20 -0000 Hi Bob, so having iperf2 actually check and report this information, obviously = is the end game here (especially reporting, the DSCP and ECN pattern = send, the patterns recswivec by the other side and what the receiver saw = in the response packets would be really helpful). But one can use tcpdump as a crude hack to get the desired information: Here are my GOTO tcpdump invocations for that purpose... # ECN IPv4/6 tcpdump -i pppoe-wan -v -n '(ip6 and (ip6[0:2] & 0x30) >> 4 !=3D 0)' or = '(ip and (ip[1] & 0x3) !=3D 0)' # NOT Not-ECT tcpdump -i pppoe-wan -v -n '(ip6 and (ip6[0:2] & 0x30) >> 4 =3D=3D 1)' = or '(ip and (ip[1] & 0x3) =3D=3D 1)' # ECT(1) tcpdump -i pppoe-wan -v -n '(ip6 and (ip6[0:2] & 0x30) >> 4 =3D=3D 2)' = or '(ip and (ip[1] & 0x3) =3D=3D 2)' # ECT(0) tcpdump -i pppoe-wan -v -n '(ip6 and (ip6[0:2] & 0x30) >> 4 =3D=3D 3)' = or '(ip and (ip[1] & 0x3) =3D=3D 3)' # CE # TCP ECN IPv4/6: (for IPv6 see see = https://ask.wireshark.org/question/27153/i-am-trying-to-capture-tcp-syn-on= -ipv6-packets-but-i-only-get-ipv4/) tcpdump -i pppoe-wan -v -n '(tcp[tcpflags] & (tcp-ece|tcp-cwr) !=3D 0)' = or '((ip6[6] =3D 6) and (ip6[53] & 0xC0 !=3D 0))' # TCP ECN flags, ECN = in action tcpdump -i pppoe-wan -v -n '(tcp[tcpflags] & tcp-ece !=3D 0)' or = '((ip6[6] =3D 6) and (ip6[53] & 0x40 !=3D 0))' # TCP ECN flags, ECE: = ECN-Echo (reported as E) tcpdump -i pppoe-wan -v -n '(tcp[tcpflags] & tcp-cwr !=3D 0)' or = '((ip6[6] =3D 6) and (ip6[53] & 0x80 !=3D 0))' # TCP ECN flags, CWR: = Congestion Window Reduced (reported as W) # IPv4/6 everything decimal DSCP 45 0x2D tcpdump -i pppoe-wan -v -n '(ip and (ip[1] & 0xfc) >> 2 =3D=3D 0x2D)' or = '(ip6 and (ip6[0:2] & 0xfc0) >> 4 =3D=3D 0x2D)' Sure this is not super convenient, but they can help a lot in quick and = dirty debugging... Note: pppoe-wan is my OpenWrt router's wan interface. > On 9. Mar 2024, at 19:43, rjmcmahon via Nnagain = wrote: >=20 > I should note that I haven't evaluated ECN marks, just that 45 gets = passed to/fro >=20 > Bob >>> [JL] Quite true: each network tends to use DSCP marks on a >>> private/internal basis and so will bleach the DSCP marks on ingress >>> from peers. This will, however, change with the upcoming IETF RFC on >>> Non-Queue-Building (NQB) Per Hop Behavior - >>> https://datatracker.ietf.org/doc/html/draft-ietf-tsvwg-nqb. And I = can >>> report that we at Comcast now permit DSCP-45 inbound for NQB = packets, >>> in case developers would like to experiment with this (we just >>> finished updating router configs last week for residential users on >>> DOCSIS; FTTP and commercial are still in process). >> iperf 2 now supports a --dscp option as a convenience (vs setting the >> --tos byte.) I can confirm --dscp 45 is being passed over my xfinity >> hop to my linodes (now Akamai) servers in both directions at multiple >> colo locations. >> The --dscp is in the master branch. >> https://sourceforge.net/p/iperf2/code/ci/master/tree/ Older versions >> require --tos and setting the byte, e.g. 180 >> Bob >> _______________________________________________ >> Nnagain mailing list >> Nnagain@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/nnagain > _______________________________________________ > Nnagain mailing list > Nnagain@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/nnagain