From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yk0-x235.google.com (mail-yk0-x235.google.com [IPv6:2607:f8b0:4002:c07::235]) (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 5FC4A21F7D6 for ; Tue, 20 Oct 2015 18:26:14 -0700 (PDT) Received: by ykaz22 with SMTP id z22so35112318yka.2 for ; Tue, 20 Oct 2015 18:26:13 -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=wh/lArgfrKSz2njoSqVfbHCVFW1hihcF2ekA4zay9kQ=; b=XmOCrZOKBVmRQfA1j+bIfD/mtftkKs8+0VG+tnf3kVU8RXOYaW6qosLPHJre4QVzAO NN6QoCZZBWwTlXcDWvrcch1KprOn5CtGqL94OBpU291vVgf+D/rRHYeofUPQMILyP+ZX FjhpVXKkNughjNhkx2EfXT1RswWm91yrB85O9jO6zJ5+ikgTs3u7BR76ofYMEaLA7vga Bdfb+uflceP/TseNa6uZkk2wIOswf6ECrdnbX5zjTtXy/3ieg6L4wzBMf5MM5C86mQt9 zZG0vd7gAb7xXPCb4ISoY3txDRNL0uDI2zIpQlQt4dRolhmO1XtXguNGMhF4/30zvva2 4GKw== MIME-Version: 1.0 X-Received: by 10.129.145.83 with SMTP id i80mr2050527ywg.77.1445390773436; Tue, 20 Oct 2015 18:26:13 -0700 (PDT) Received: by 10.13.236.131 with HTTP; Tue, 20 Oct 2015 18:26:13 -0700 (PDT) In-Reply-To: <56267AB6.6080604@darbyshire-bryant.me.uk> References: <9717A3D5-6BF8-4454-A664-AAE4D276C942@gmx.de> <302F7EC4-80C4-42D3-AD9B-E555AD8FE4A5@gmx.de> <56267AB6.6080604@darbyshire-bryant.me.uk> Date: Tue, 20 Oct 2015 20:26:13 -0500 Message-ID: From: Benjamin Cronce To: Kevin Darbyshire-Bryant Content-Type: multipart/alternative; boundary=94eb2c093a329ccb69052293431c Cc: cake@lists.bufferbloat.net Subject: Re: [Cake] Cake over satellite X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 21 Oct 2015 01:26:37 -0000 --94eb2c093a329ccb69052293431c Content-Type: text/plain; charset=UTF-8 Because planet very way too much and even a given planet will have a wide range of much greater than one our RTTs. TCP probably won't even work for those kids of RTTs. What about a Lunar RTT instead of Interplanetary? The moon is about 1.3 light seconds away, one way. That's a minimum of 2.6sec RTT. On Tue, Oct 20, 2015 at 12:32 PM, Kevin Darbyshire-Bryant < kevin@darbyshire-bryant.me.uk> wrote: > On 19/10/15 20:05, Sebastian Moeller wrote: > > Hi, > > > > On October 19, 2015 10:24:01 AM CDT, Dave Taht > wrote: > >> well, yes, but we can do it in the lab *this week*, before he takes > >> the dingos on.... > > Good idea, als I am at A conference right now and will not find the time > to make the changes to TC in time. I believe that cake should certainly A) > set A reasonable target by default and B) still allow the user to > explicitly request something else. Currently, I believe cake does only A)... > > > > Besteht Regards > > Sebadtian > > > > > > As an FYI: > > > tc has a number of calculations for interval & target > > If an rtt is specified then target is 5% of interval with 1uS > (microsecond!) and 5mS (millisecond) lower & upper bounds. > > The keyword predefined rtt values are: > > datacentre (100uS), lan (1mS), metro(10mS), regional(30mS), > internet(100mS), oceanic(300mS), satellite(1000mS), interplanetary(1hour!) > Corresponding targets are 5uS, 50uS, 500uS, 1.5mS and everything from > internet onwards as a 5mS target. > > Although these are the values passed into cake from tc, that isn't the > final story with regard to calculations as cake qdisc has some further > sanity checks. > > If a link bandwidth is specified then the target is set to the max of > '1.5 MTU's worth of link time' and the target value passed by tc. The > interval is set to max of '8 times the calculated target' and interval > value passed by tc. > > So whilst tc supplies an rtt/interval and a 5% calculated target, cake > itself will override this with sensible values if that makes sense for a > 'slow' link. > > Kevin > > > _______________________________________________ > Cake mailing list > Cake@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cake > > --94eb2c093a329ccb69052293431c Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Because planet very way too much and even a given planet w= ill have a wide range of much greater than one our RTTs. TCP probably won&#= 39;t even work for those kids of RTTs. What about a Lunar RTT instead of In= terplanetary? The moon is about 1.3 light seconds away, one way. That's= a minimum of 2.6sec RTT.

On Tue, Oct 20, 2015 at 12:32 PM, Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk> wrote:
On 19/10/15 20:05, Sebastian Moeller wrote:
> Hi,
>
> On October 19, 2015 10:24:01 AM CDT, Dave Taht <dave.taht@gmail.com> wrote:
>> well, yes, but we can do it in the lab *this week*, before he take= s
>> the dingos on....
> Good idea, als I am at A conference right now and will not find the ti= me to make the changes to TC in time. I believe that cake should certainly = A) set A reasonable target by default and B) still allow the user to explic= itly request something else. Currently, I believe cake does only A)...
>
> Besteht Regards
>=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Sebadtian
>
>

As an FYI:


tc has a number of calculations for interval & target

If an rtt is specified then target is 5% of interval with 1uS
(microsecond!) and 5mS (millisecond) lower & upper bounds.

The keyword predefined rtt values are:

datacentre (100uS), lan (1mS), metro(10mS), regional(30mS),
internet(100mS), oceanic(300mS), satellite(1000mS), interplanetary(1hour!)<= br> Corresponding targets are 5uS, 50uS, 500uS, 1.5mS and everything from
internet onwards as a 5mS target.

Although these are the values passed into cake from tc, that isn't the<= br> final story with regard to calculations as cake qdisc has some further
sanity checks.

If a link bandwidth is specified then the target is set to the max of
'1.5 MTU's worth of link time' and the target value passed by t= c.=C2=A0 The
interval is set to max of '8 times the calculated target' and inter= val
value passed by tc.

So whilst tc supplies an rtt/interval and a 5% calculated target, cake
itself will override this with sensible values if that makes sense for a 'slow' link.

Kevin


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