From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Furniss Date: Thu, 16 Jun 2005 14:21:40 +0000 Subject: Re: [LARTC] ADSL Calculator Message-Id: <42B18AF4.5060703@dsl.pipex.com> List-Id: References: <20050614220232.GA17110@yamamaya.is-a-geek.org> In-Reply-To: <20050614220232.GA17110@yamamaya.is-a-geek.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org Andy Furniss wrote: > Tobias Diedrich wrote: > >> Hi, >> >> I've written a small javascript ADSL throughput calculator: >> http://nukunuku.yamamaya.is-a-geek.org/~ranma/adsl.html >> >> Feel free to submit alternative presets (I currently have presets >> for three german telecom speed variants: T-DSL (1000|2000|3000), >> derived from >> http://www2.lancom.de/kb.nsf/5d445c701b3ff52dc1256e7700297e5c/27c6ee1c3e3f74b0c1256e94004a433e?OpenDocument). >> >> >> Comments, suggestions, spelling nitpicks? >> > > Looks good - one picky point - if your overhead means only 4 bytes > padding at default mtu are needed, then reducing mtu to be "optimal" for > IP and above levels may be less efficient from the point of view of the > tcp data because of the reduced payload vs fixed overheads. > > I haven't done the maths on that :-) Which I should have done first :-) If timestamps are off it's still about 1 1/3 bytes per frame more efficient. If they are on (default on linux costing 12 bytes) the smaller mtu is about 1 byte per frame less efficient. Andy. _______________________________________________ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc