From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x241.google.com (mail-pf0-x241.google.com [IPv6:2607:f8b0:400e:c00::241]) (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 79FF33BA8E for ; Fri, 17 Nov 2017 16:19:54 -0500 (EST) Received: by mail-pf0-x241.google.com with SMTP id n89so2794156pfk.11 for ; Fri, 17 Nov 2017 13:19:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=0KEPPinh+eS0gys6ZywmRgBXLjq+0WHlvLsFzgvLIsk=; b=YemntuYMjJCXRZhR/evrFhZhbq3ssVKESQETe6UXgFJkAzp9315jPP2qsnJq9+sXDw 0LKc3vuwLtjJbU0oUURcP6UHrbpGm75+ItTRaSVVsmtOGDphgk9G8gs+ApoavXroy1rE XZamLCqKuzLiujc9tVIXTNx3MGE9JNE1tw+2yX2P/o8Sw1XZ9akr07hwIJlFXlnWewCr EyIIPPrx1oQA1FfrMnsHcPzXrN9Mls44AhEEFvttcIAqz798gImf317bQP/AVmPq4mq3 EUp3dlYZShKGaAOEY9yNkz81OgYccjJeIZoomyxYFulDceRIWGtNP1igF3lGAwLDmQtZ jfJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=0KEPPinh+eS0gys6ZywmRgBXLjq+0WHlvLsFzgvLIsk=; b=RmFTGtma0U2eTPMBjM9ogC057/BD4nQqgwmIV5tPwPK8f/DrfH8cvhaD8JxP44Jx/3 TiGK44loYL4Qoqa7Obu3ex8X+S12CIpgfX8VNU8lEeai4Bb2qxBIPjqXTK8XpPL67F5V xhH52ULUuyHYimPysNtEPQTapjVE2utuG3XAfGFFudFkuMetMx7nxYKVMM0Uh1a2WhX4 H37hrw2xqAAOYqumIwCnVqps9hiQxlDBGcrAT+n9VLb16Wn7g8Rh9byU9EjxFAcjRBCp emcL83eWIbqf9y640JdFKgCLC0w8tMpYaFFFTZfg63Qe4IQ0Za82eatBdRBJtr+Tuw/9 3bww== X-Gm-Message-State: AJaThX5iUe+Ppt6xd53LFA4scCzbHYazqUrzpbQQYSRU8tv+hLCAbZ5v 6FlCvfpbZcfKcPlqVJCyDYsqsg== X-Google-Smtp-Source: AGs4zMa3NwEbElbfg67pwFgdyOEcOBiL/sl425XFOAD2b1RfLI+ffFf2rgYGl2chUkGh1Nl3VrxFyg== X-Received: by 10.99.134.73 with SMTP id x70mr6441933pgd.130.1510953593555; Fri, 17 Nov 2017 13:19:53 -0800 (PST) Received: from nemesis.lab.teklibre.com (c-24-6-113-161.hsd1.ca.comcast.net. [24.6.113.161]) by smtp.gmail.com with ESMTPSA id r68sm8747869pfb.149.2017.11.17.13.19.52 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 17 Nov 2017 13:19:53 -0800 (PST) From: Dave Taht To: cake@lists.bufferbloat.net Date: Fri, 17 Nov 2017 13:19:28 -0800 Message-Id: <1510953568-11797-6-git-send-email-dave.taht@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1510953568-11797-1-git-send-email-dave.taht@gmail.com> References: <1510953568-11797-1-git-send-email-dave.taht@gmail.com> Subject: [Cake] [RFC PATCH 5/5] netem: add documentation for the new slotting feature X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Nov 2017 21:19:54 -0000 --- man/man8/tc-netem.8 | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/man/man8/tc-netem.8 b/man/man8/tc-netem.8 index b31384f..8c41d77 100644 --- a/man/man8/tc-netem.8 +++ b/man/man8/tc-netem.8 @@ -8,7 +8,8 @@ NetEm \- Network Emulator .I OPTIONS .IR OPTIONS " := [ " LIMIT " ] [ " DELAY " ] [ " LOSS \ -" ] [ " CORRUPT " ] [ " DUPLICATION " ] [ " REORDERING " ][ " RATE " ]" +" ] [ " CORRUPT " ] [ " DUPLICATION " ] [ " REORDERING " ] [ " RATE \ +" ] [ " SLOT " ]" .IR LIMIT " := " .B limit @@ -51,6 +52,14 @@ NetEm \- Network Emulator .B rate .IR RATE " [ " PACKETOVERHEAD " [ " CELLSIZE " [ " CELLOVERHEAD " ]]]]" +.IR SLOT " := " +.BR slot +.IR MIN_DELAY " [ " MAX_DELAY " ] {[" +.BR packets +.IR PACKETS " ] [ " +.BR bytes +.IR BYTES " ] }]" + .SH DESCRIPTION NetEm is an enhancement of the Linux traffic control facilities @@ -162,6 +171,27 @@ granularity avoid a perfect shaping at a specific level. This will show up in an artificial packet compression (bursts). Another influence factor are network adapter buffers which can also add artificial delay. +.SS slot +defer delivering accumulated packets to within a slot, with each available slot +configured with a minimum delay to acquire, and an optional maximum delay. Slot +delays can be specified in nanoseconds, microseconds, milliseconds or seconds +(e.g. 800us). Values for the optional parameters +.I BYTES +will limit the number of bytes delivered per slot, and/or +.I PACKETS +will limit the number of packets delivered per slot. + +These slot options can provide a crude approximation of bursty MACs such as +DOCSIS, WiFi, and LTE. + +Note that slotting is limited by several factors: the kernel clock granularity, +as with a rate, and attempts to deliver many packets within a slot will be +smeared by the timer resolution, and by the underlying native bandwidth also. + +It is possible to combine slotting with a rate, in which case complex behaviors +where either the rate, or the slot limits on bytes or packets per slot, govern +the actual delivered rate. + .SH LIMITATIONS The main known limitation of Netem are related to timer granularity, since Linux is not a real-time operating system. -- 2.7.4