From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-x241.google.com (mail-lf0-x241.google.com [IPv6:2a00:1450:4010:c07::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 942E43B2A0 for ; Fri, 17 Jun 2016 23:06:52 -0400 (EDT) Received: by mail-lf0-x241.google.com with SMTP id l188so1184705lfe.0 for ; Fri, 17 Jun 2016 20:06:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=FDiiMqRAgycjXUK5aHXCKkvYaKCIdUfP8jZOC8q4q1c=; b=axjLJKY5TweRdIegC7owRiiWZiyylBpflTOX3b4zPqIFIOY8sVoAthJ6m9sEnc00f/ lGDywn+zWk5EfVINr/8Q3ad4TmB7sHPP7P+VWEYsc4IovbuGmWsORSmmtAGq2/DZmJ1A bZRFkihLpE3Zek2NBlxejBIXOyo5F5ODbqwqbmhDpkxz9ksHXRtAFS4Rz1kFUy0OH0nv tFjsDjU2rn8jbKskHgdSeA9/EGHLNOI7aSS7juI/ATXXfG6lxS2F5SaowVTQ9Uai5YnJ fpd859xmo/kqMU4ui6evci4xC99FtrhA8EZctAFjLRsX7AzT84k/Gk2QcTdq4/BLkF5w nQbw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=FDiiMqRAgycjXUK5aHXCKkvYaKCIdUfP8jZOC8q4q1c=; b=UzLw1Fam4HRhuuiPg4V9ZPiQazuy4anx5RDnl22VTD0Jb31Awb0VgypvPR9FqxAc0M WBB7JMT7DvCK3RAgWX6FLmFGnL7vBfc8BAf87scp+u9b4A52xTco3ezB5IRhirZXUQE+ xDDKgsGJxalNv3FmHSTQy+qJPXiveMPVyPHL2+kgoSHRasO/wZfXO80fhiuAHkTmTXoB 3L1rgOCjm0gT9ltjv6XoU/C95mm8xSUKbRHfLyT8iseAe2OyVikPSMs+dPoFkv8urvCh S76TYa+Cd8SgA7PuZkylnA9WsnZgQHjDFGfk2dYmod1ipxaiWMqfbhRueXdCbGuuEqqG TTwQ== X-Gm-Message-State: ALyK8tKcK3YnpkLqf47Jz16Dut2i7n3sTtRNbqYaV26uQN9jHfMOhuYsC71r/OR0SctQog== X-Received: by 10.25.21.165 with SMTP id 37mr1167602lfv.1.1466219211359; Fri, 17 Jun 2016 20:06:51 -0700 (PDT) Received: from bass.home.chromatix.fi (37-33-112-183.bb.dnainternet.fi. [37.33.112.183]) by smtp.gmail.com with ESMTPSA id e17sm5453900lji.32.2016.06.17.20.06.49 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 17 Jun 2016 20:06:50 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) From: Jonathan Morton In-Reply-To: <548a7871-e2b9-4802-3508-e57f34368096@gmail.com> Date: Sat, 18 Jun 2016 06:06:44 +0300 Cc: bloat@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <0D81073C-4F45-40E4-84CD-CC61BF8001A7@gmail.com> References: <548a7871-e2b9-4802-3508-e57f34368096@gmail.com> To: Noah Causin X-Mailer: Apple Mail (2.3124) Subject: Re: [Bloat] USB Ethernet Adapters with BQL? X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 18 Jun 2016 03:06:52 -0000 > On 17 Jun, 2016, at 22:42, Noah Causin wrote: >=20 > I was looking into getting a USB 3.0 Gigabit Ethernet adapter, and I = was trying to find ones that had BQL support in their drivers. >=20 > Are there any good ones out there, or is there something related to = USB that reduces this feature's effectiveness? Because the USB protocol gives greater decoupling between host and = device than PCI (or PCIe) does, USB Ethernet adapters don=E2=80=99t have = a general, explicit signal to indicate when packets are actually = transmitted on the wire, or an easy low-latency way to discover the = instantaneous buffer fill level (besides =E2=80=9Cfull=E2=80=9D vs. = =E2=80=9Cnot full=E2=80=9D). This makes implementing BQL challenging. I=E2=80=99m not personally aware of any USB adapters with BQL. That = doesn=E2=80=99t mean there aren=E2=80=99t any. - Jonathan Morton