From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XCy6q-0002Ri-CX for bitcoin-development@lists.sourceforge.net; Thu, 31 Jul 2014 21:42:00 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.219.44 as permitted sender) client-ip=209.85.219.44; envelope-from=keziahw@gmail.com; helo=mail-oa0-f44.google.com; Received: from mail-oa0-f44.google.com ([209.85.219.44]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1XCy6p-0007fF-B5 for bitcoin-development@lists.sourceforge.net; Thu, 31 Jul 2014 21:42:00 +0000 Received: by mail-oa0-f44.google.com with SMTP id eb12so2498249oac.3 for ; Thu, 31 Jul 2014 14:41:53 -0700 (PDT) X-Received: by 10.60.45.140 with SMTP id n12mr1537418oem.48.1406842913920; Thu, 31 Jul 2014 14:41:53 -0700 (PDT) MIME-Version: 1.0 Received: by 10.202.61.195 with HTTP; Thu, 31 Jul 2014 14:41:33 -0700 (PDT) In-Reply-To: References: From: Kaz Wesley Date: Thu, 31 Jul 2014 14:41:33 -0700 Message-ID: To: Gregory Maxwell Content-Type: text/plain; charset=UTF-8 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 (keziahw[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 X-Headers-End: 1XCy6p-0007fF-B5 Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Squashing redundant tx data in blocks on the wire 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: Thu, 31 Jul 2014 21:42:00 -0000 > the need to have transmitted the transaction list [..] first 32 bits per transaction is at least double the communication overhead of the simple approach, and only offers a bound on the probability of needing a round trip. On Thu, Jul 31, 2014 at 2:29 PM, Gregory Maxwell wrote: > On Thu, Jul 31, 2014 at 1:47 PM, Kaz Wesley wrote: >> trip to request the missing tx; if we could somehow get the "What's >> the Difference" approach to effectively operate on full transactions >> instead > > I explain how to do this on the network block coding page. > > Given that you know the sizes and orders of the transactions (e.g. > from a reconciliation step first), the sender sends non-syndromic > forward error correcting code data somewhat larger than their estimate > of how much data the user is missing. Then you drop the data you know > into place and then recover the missing blocks using the fec. > > There is no overhead in this approach except for FEC blocks that are > incompletely missing (and so must be completely discarded), and the > need to have the transmitted the transaction list and sizes first. > (note, that just more bandwidth, not an additional round trip).