Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1X8Kyh-0002w8-L3 for bitcoin-development@lists.sourceforge.net; Sat, 19 Jul 2014 03:06:27 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.219.48 as permitted sender) client-ip=209.85.219.48; envelope-from=el33th4x0r@gmail.com; helo=mail-oa0-f48.google.com; Received: from mail-oa0-f48.google.com ([209.85.219.48]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1X8Kyg-0002KI-RH for bitcoin-development@lists.sourceforge.net; Sat, 19 Jul 2014 03:06:27 +0000 Received: by mail-oa0-f48.google.com with SMTP id m1so4536229oag.21 for ; Fri, 18 Jul 2014 20:06:21 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.182.20.135 with SMTP id n7mr12917041obe.36.1405739181298; Fri, 18 Jul 2014 20:06:21 -0700 (PDT) Received: by 10.76.23.193 with HTTP; Fri, 18 Jul 2014 20:06:21 -0700 (PDT) Received: by 10.76.23.193 with HTTP; Fri, 18 Jul 2014 20:06:21 -0700 (PDT) In-Reply-To: References: Date: Fri, 18 Jul 2014 23:06:21 -0400 Message-ID: From: =?UTF-8?Q?Emin_G=C3=BCn_Sirer?= To: Gregory Maxwell Content-Type: multipart/alternative; boundary=e89a8f83a7c98c5a7f04fe8328d9 X-Spam-Score: -0.6 (/) 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 (el33th4x0r[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message -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: 1X8Kyg-0002KI-RH 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: Sat, 19 Jul 2014 03:06:27 -0000 --e89a8f83a7c98c5a7f04fe8328d9 Content-Type: text/plain; charset=UTF-8 > Most things I've seen working in this space are attempting to minimize > the data transfered. At least for the miner-interested case the round > complexity is much more important because a single RTT is enough to > basically send the whole block on a lot of very relevant paths. Agreed. Yaron's scheme is magical because it is non-interactive. I send you a packet of O(expected-delta) and you immediately figure out the delta without further back and forth communication, each requiring an RTT. > I know much better is possible (see up-thread where I linked to an old > proposal to use forward error correction to transfer with low data > transfer (but not optimal) and negligible probability of needing a > round-trip, with a tradeoff for more overhead for lower roundtrip > probability). FEC schemes are both fairly complex, because the set is constantly changing, and (if i understand your suggestion correctly) they add additional metadata overhead (albeit mostly during tx propagation). Set reconciliation is near optimal. In any case, I have no horse here (I think changing the client so it's multithreaded is the best way to go), but Yaron's work is pretty cool and may be applicable. - egs --e89a8f83a7c98c5a7f04fe8328d9 Content-Type: text/html; charset=UTF-8


> Most things I've seen working in this space are attempting to minimize
> the data transfered. At least for the miner-interested case the round
> complexity is much more important because a single RTT is enough to
> basically send the whole block on a lot of very relevant paths.

Agreed. Yaron's scheme is magical because it is non-interactive. I send you a packet of O(expected-delta) and you immediately figure out the delta without further back and forth communication, each requiring an RTT.

> I know much better is possible (see up-thread where I linked to an old
> proposal to use forward error correction to transfer with low data
> transfer (but not optimal) and negligible probability of needing a
> round-trip, with a tradeoff for more overhead for lower roundtrip
> probability).

FEC schemes are both fairly complex, because the set is constantly changing, and (if i understand your suggestion correctly) they add additional metadata overhead (albeit mostly during tx propagation). Set reconciliation is near optimal.

In any case, I have no horse here (I think changing the client so it's multithreaded is the best way to go), but Yaron's work is pretty cool and may be applicable.

- egs

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