From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1QpK3X-0002fP-Jq for bitcoin-development@lists.sourceforge.net; Fri, 05 Aug 2011 13:03:15 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 74.125.82.175 as permitted sender) client-ip=74.125.82.175; envelope-from=andyparkins@gmail.com; helo=mail-wy0-f175.google.com; Received: from mail-wy0-f175.google.com ([74.125.82.175]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1QpK3W-000781-Om for bitcoin-development@lists.sourceforge.net; Fri, 05 Aug 2011 13:03:15 +0000 Received: by wyf19 with SMTP id 19so270349wyf.34 for ; Fri, 05 Aug 2011 06:03:08 -0700 (PDT) Received: by 10.227.146.209 with SMTP id i17mr1808265wbv.28.1312549388329; Fri, 05 Aug 2011 06:03:08 -0700 (PDT) Received: from dvr.localnet (mail.360visiontechnology.com [92.42.121.178]) by mx.google.com with ESMTPS id fp3sm2277558wbb.64.2011.08.05.06.03.06 (version=TLSv1/SSLv3 cipher=OTHER); Fri, 05 Aug 2011 06:03:07 -0700 (PDT) From: Andy Parkins To: bitcoin-development@lists.sourceforge.net Date: Fri, 5 Aug 2011 14:03:05 +0100 User-Agent: KMail/1.13.6 (Linux/2.6.38-2-686; KDE/4.6.3; i686; ; ) References: <201108041423.14176.andyparkins@gmail.com> <201108051258.25813.andyparkins@gmail.com> <1312545969.4516.8.camel@BMThinkPad.lan.bluematt.me> In-Reply-To: <1312545969.4516.8.camel@BMThinkPad.lan.bluematt.me> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1768847.8MR82ZS5ip"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <201108051403.05506.andyparkins@gmail.com> X-Spam-Score: -1.6 (-) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (andyparkins[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.0 T_TO_NO_BRKTS_FREEMAIL To: misformatted and free email service -0.0 AWL AWL: From: address is in the auto white-list X-Headers-End: 1QpK3W-000781-Om Subject: Re: [Bitcoin-development] Double spend detection to speed up transaction trust X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Aug 2011 13:03:15 -0000 --nextPart1768847.8MR82ZS5ip Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable On 2011 August 05 Friday, Matt Corallo wrote: > On Fri, 2011-08-05 at 12:58 +0100, Andy Parkins wrote: > > I don't really see that "number of connections" is the relevant metric. >=20 > Number of connections is something that needs serious thought. Too many > and you fill everyone's connection slots and no one can make > connections. Too few and you don't have a network but just a bunch of > islands which would also cause serious problems. > If you aren't relaying, each connection takes almost no bandwidth, so > the question is how many do you need to be considered secure. I'm arguing that "number of connection slots" isn't the best metric; so tha= t=20 wouldn't matter. Just keep accepting incoming connections (with some sanit= y=20 limit of course) until you've allocated your bandwidth, not your number of= =20 connections. If I connect to a thousand nodes and never send anything, I'm not using up= =20 very much of their resources. If _they_ want to use up resources by relayi= ng,=20 then that is their choice, but again they can do that based on bandwidth=20 calculations rather than connection counts. If I am sending, then that add= s=20 to their bandwidth and gets included in whatever limit they've chosen. =46or example: the client could simply maintain an average bandwidth over a= ll=20 connections. If that average is less than threshold0, then make new outgoi= ng=20 connections. If that average exceeds threshold1, then stop accepting incom= ing=20 connections. If it exceeds threshold2, start dropping established incoming= =20 connections. If it exceeds theshold3, start dropping established outgoing= =20 connections. The actual rules don't matter so much; I'm just saying bandwidth is a bette= r=20 metric than connection count. If you limit by connection count, then you'l= l=20 just end up filled with non-relaying listeners, since they (in the future)= =20 will be the most commonplace. You'll have no incoming relays, and therefor= e=20 nothing to forward, so your bandwidth will be zero, but your connection cou= nt=20 at maximum -- you've locked yourself out. Andy =2D-=20 Dr Andy Parkins andyparkins@gmail.com --nextPart1768847.8MR82ZS5ip Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEABECAAYFAk476gkACgkQwQJ9gE9xL21McQCeM800bGwT7by8dNlp3T2zanjd LCYAnRjAdCQC2rrbvt+ypZVAJ+TIgMs0 =V3BY -----END PGP SIGNATURE----- --nextPart1768847.8MR82ZS5ip--