From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-gg0-f171.google.com (mail-gg0-f171.google.com [209.85.161.171]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id F3F7D21F15A for ; Wed, 28 Nov 2012 08:39:53 -0800 (PST) Received: by mail-gg0-f171.google.com with SMTP id 4so1489736ggm.16 for ; Wed, 28 Nov 2012 08:39:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:reply-to:in-reply-to:references:from:date:message-id :subject:to:cc:content-type; bh=2i+BG9iXHMUL10rGI7b4VL/nkEh6ucYhm9fjpdBrl+8=; b=l1fTB9O+JD+Vzu2tBCp/tACkEAp/TphcOiSM5OgUbynInm+havpLlkl0TBvDOxXrLn /QnOEZRVjKOazk0Ep9wPT2Vi3QOKdBeb4jNY5XG4T8lYNwin/SD/KArIKupZyyWTddEy e530iwjLO4SvW/DMK60owF3U+SSRBGwTYD96axTZQrbVGDgVL0Sv2aQzjeTYRGLC932T 34/oBQlR/tNnfat7CCmzE+ruabO9gFOmhk/CyMmmDGZ8lRkdlyfh69+xtK5EEgMa0T4p 6eleLAEEJN/iGKYbw2O9idUJKz6+T4puOZ/6BzSTLukQDzMZh7CYe9/lJZ9dERWVLn/v InVw== Received: by 10.58.187.84 with SMTP id fq20mr29825843vec.25.1354120792613; Wed, 28 Nov 2012 08:39:52 -0800 (PST) MIME-Version: 1.0 Received: by 10.58.169.66 with HTTP; Wed, 28 Nov 2012 08:39:31 -0800 (PST) In-Reply-To: References: From: Dave Hart Date: Wed, 28 Nov 2012 16:39:31 +0000 Message-ID: To: Dauran raza Content-Type: text/plain; charset=ISO-8859-1 Cc: bloat@lists.bufferbloat.net Subject: Re: [Bloat] Bufferbloat research: Help required X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list Reply-To: davehart_gmail_exchange_tee@davehart.net List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Nov 2012 16:39:54 -0000 On Sun, Nov 25, 2012 at 3:21 PM, Dauran raza wrote: > My name is Dauran Raza and i am currently doing Masters in Computer Science > from University Paderborn. Currently i am researching on the Problem of > Bufferbloat for a course under Prof Holger Karl. I have been regularly > reading you articles on your websites about this problem and it has been > really helpfull. I have a problem which is not answered so far through any > research paper. I wanted to know is there any difference in Wired and > Wireless networks caused by this problem and can you guide me with any good > paper or article to read on. I wish you well in your graduate studies, and I commend Prof. Holger Karl for his interest in the topic. I am, however, cautious that I don't want to do your research for you. Briefly, as you would hopefully anticipate, wireless presents more challenges to addressing bufferbloat than wired. For example, the jitter (delay variability) is much worse than wired, and 802.11n requires aggregation of multiple packets into one transmission to achieve its higher throughputs vs. 802.11g, which further increases jitter and complicates AQM. Even ignoring wireless, gigabit wired is more challenging than 100 Mbit, again because techniques used to maximize peak throughput (such as deeper transmit buffers and receive interrupt coalescing) tend to make bufferbloat more of a challenge. There's a theme here -- those developing network advancements have tended to focus on maximizing achievable throughput without enough consideration of the negative effects on bufferbloat, often (at least historically) with no understanding of bufferbloat at all. I pray I have not said too much already, and if I have, please convey my apologies to Prof. Karl. I suggest digging into the mailing list archives: https://lists.bufferbloat.net/listinfo I'd start with the bloat and bloat-devel lists, then the Codel-related lists, and possibly other -devel and -commit lists. Also, if you make yourself useful in one or more bufferbloat.net projects, you will gain firsthand knowledge of the issues as well as personal relationships with people well-versed in the issues. Thanks for your interest, Dave Hart