From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-x232.google.com (mail-ie0-x232.google.com [IPv6:2607:f8b0:4001:c03::232]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id A78E221F513 for ; Sat, 18 Apr 2015 15:12:22 -0700 (PDT) Received: by iecrt8 with SMTP id rt8so81657015iec.0 for ; Sat, 18 Apr 2015 15:12:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=tc9bvk2wmHzjRegp6kUt5HCha5hH2QF6/JOItN/f0W0=; b=DbJA5M4ovKcnwm5WBLTckAF4V/KfStnjzWVhleJ3XER1eIcdof6mHgBVr6xQNHSm/Q KK+NwzPb/1/5/Ay3GLeETiTe2xQ9EN6BnGtH2+xS5arMzwsinRMq7k2iVpzDfMAHXclQ cnNG77KqyMRlPKlvmR08U0VHYI0rxVocuxHD5dZ2OkrnRGE/uViJ+D6eKkMziYtQqfva aC2LpeP5Ozj6L9Th6UH7I2OKiPOjPbfIegZyPdhZWhsEkNb0dZTVtfC8FFb7tEA4EACf mvc4o1gjyYgDgD5T5I48K2A1uzY8iujvFLPhuAfWnwujT2lKJRTZMMXJB2TchZ6fq9Im 5zDg== MIME-Version: 1.0 X-Received: by 10.50.225.35 with SMTP id rh3mr11529565igc.29.1429395141655; Sat, 18 Apr 2015 15:12:21 -0700 (PDT) Received: by 10.107.131.66 with HTTP; Sat, 18 Apr 2015 15:12:21 -0700 (PDT) Received: by 10.107.131.66 with HTTP; Sat, 18 Apr 2015 15:12:21 -0700 (PDT) In-Reply-To: References: Date: Sat, 18 Apr 2015 15:12:21 -0700 Message-ID: From: Ketan Kulkarni To: David Lang Content-Type: multipart/alternative; boundary=001a1132f214a982ee051406fd98 Cc: bloat Subject: Re: [Bloat] Bufferbloat in switches and routers X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 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 Apr 2015 22:12:50 -0000 --001a1132f214a982ee051406fd98 Content-Type: text/plain; charset=UTF-8 On Apr 18, 2015 13:33, "David Lang" wrote: > > On Sat, 18 Apr 2015, Ketan Kulkarni wrote: > >> Hi, >> We have been talking about the bloated buffers mostly on the home routers. >> The Cisco PIE too has been standardized by docsis meant to be for cable >> modems >> >> I think we would have similar concerns for switches and routers. (E.g. >> cat3k switches or Cisco 5760 controllers just to name) > > > remember that bufferbloat shows up where there is a difference in bandwidth from one side of the router to the other (i.e. a bottleneck) > Thanks this makes the devices easier to target. > This is almost always going to happen at the edge of your LAN where you go from your Gig-E (or in a datacenter, possibly 10Gig-E to your WAN link. It can happen at places inside your datacenter, but isn't as likely > Agree. As per my (limited) knowledge of such deployment goes, these probably never run to their peak capacity in the production/live system probably not even to saturate the lowest of the links( I may be wrong though) . Given this, what is the gravity of the effect of the bufferbloat? Or such study has never been done before? Having AQM won't definitely hurt, however is it indeed a real problem to solve for such edge routers? At the same time I hear codel or pie finding the space in data centers. So there are definitely some pieces I am missing. Sorry for being little naive but the answers will definitely help me understand the problem space and spread more awareness about bufferbloat. > >> I would like to know your views about what you think about it . >> Are the theories so far and the AQMs (codel and pie) stand true for such >> devices too? > > > If they are bottlenecks, yes. If they are not bottlenecks it won't hurt (no queues will build up > > >> What would it take to measure the bloat levels of these devices? Do we >> still need to use the netperf wrapper to get the characteristics of such >> devices? > > > the same approach works. you may need beefier systems to generate sufficient load. > > David Lang > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat > --001a1132f214a982ee051406fd98 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable


On Apr 18, 2015 13:33, "David Lang" <david@lang.hm> wrote:
>
> On Sat, 18 Apr 2015, Ketan Kulkarni wrote:
>
>> Hi,
>> We have been talking about the bloated buffers mostly on the home = routers.
>> The Cisco PIE too has been standardized by docsis meant to be for = cable
>> modems
>>
>> I think we would have similar concerns for switches and routers. (= E.g.
>> cat3k switches or Cisco 5760 controllers just to name)
>
>
> remember that bufferbloat shows up where there is a difference in band= width from one side of the router to the other (i.e. a bottleneck)
>
Thanks this makes the devices easier to target.

> This is almost always going to happen at the edge of yo= ur LAN where you go from your Gig-E (or in a datacenter, possibly 10Gig-E t= o your WAN link. It can happen at places inside your datacenter, but isn= 9;t as likely
>
Agree. As per my (limited) knowledge of such deployment goes, these probabl= y never run to their peak capacity in the production/live system probably n= ot even to saturate the lowest of the links( I may be wrong though) . Given= this, what is the gravity of the effect of the bufferbloat? Or such study = has never been done before?

Having AQM won't definitely hurt, however is it indeed a= real problem to solve for such edge routers?

At the same time I hear codel or pie finding the space in da= ta centers. So there are definitely some pieces I am missing.

Sorry for being little naive but the answers will definitely= help me understand the problem space and spread more awareness about buffe= rbloat.

>
>> I would like to know your views about what you think about it . >> Are the theories so far and the AQMs=C2=A0 (codel and pie) stand t= rue for such
>> devices too?
>
>
> If they are bottlenecks, yes. If they are not bottlenecks it won't= hurt (no queues will build up
>
>
>> What would it take to measure the bloat levels of these devices? D= o we
>> still need to use the netperf wrapper to get the characteristics o= f such
>> devices?
>
>
> the same approach works. you may need beefier systems to generate suff= icient load.
>
> David Lang
> _______________________________________________
> Bloat mailing list
> Bloat@lists.bufferbloat= .net
> https://lists= .bufferbloat.net/listinfo/bloat
>

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