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In-Reply-To: <CA+8xBpe9D=poPyJ=soGdN3sovqdmvyGGij6FM8PHYGUB5aUkzQ@mail.gmail.com>
References: <CA+8xBpe9D=poPyJ=soGdN3sovqdmvyGGij6FM8PHYGUB5aUkzQ@mail.gmail.com>
Date: Sat, 23 Mar 2013 15:30:22 -0700
Message-ID: <CACh7GpFqZtWVQFjM-w1uoB+74sVvE=_mXwBQ4P-qGMp2=HJ_yQ@mail.gmail.com>
From: Mark Friedenbach <mark@monetize.io>
To: Jeff Garzik <jgarzik@exmulti.com>
Content-Type: multipart/alternative; boundary=047d7b6229260995d304d89f1e68
Cc: Bitcoin Development <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] A bitcoin UDP P2P protocol extension
Precedence: list

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If you're considering a datagram protocol, you might be interested in some
more modern alternatives to UDP:

UDT: Breaking the Data Transfer Bottleneck
http://udt.sourceforge.net/

Stream Control Transmission Protocol
http://en.wikipedia.org/wiki/Stream_Control_Transmission_Protocol



On Sat, Mar 23, 2013 at 12:17 AM, Jeff Garzik <jgarzik@exmulti.com> wrote:

> Here is a rough draft implementation of a UDP P2P protocol extension
> for bitcoin:
>
>      https://github.com/jgarzik/bitcoin/tree/udp
>      http://yyz.us/bitcoin/udp-v0.patch
>
> Protocol specification (such that it is):
>
> - UDP, bound to same port as TCP P2P (normally 8333)
> - Active, simultaneous TCP P2P connection required (useful against DoS
> and other attacks)
> - Same message format as TCP P2P, same pchMessageStart conventions,
> etc. (my CNetMessage pull req would be helpful here)
> - Multiple P2P messages per UDP packet permitted
> - Max UDP packet size 100*1024 bytes
> - Advertises NODE_UDP in nServices
> - New "getudpcook" TCP P2P command returns a "udpcook" message,
> containing a yummy cookie
> - UDP P2P commands "inv", "tx" and "addr" are handled as if received via
> TCP
> - UDP P2P command "udpsub" sets a mask, that subscribes to one or more
> data broadcasts.
> - When USM_INV_BCAST mask bit is set, receive "inv" messages via UDP
> rather than TCP.
>
> Project and design goals (or, why do this?):
>
> - It is theorized that UDP may be useful for some messages we
> broadcast throughout the network
> - A productive discussion STARTS with code, otherwise discussion
> continues forever.
> - Investigate improving "inv" relay speed
> - Investigate unconditional "tx" broadcasting via UDP, as "inv"
> alternative, for small tx's.
> - Investigate improving block relay speed (or perhaps block header relay
> speed)
> - Open up new design avenues, for P2P patterns more suited to UDP than
> TCP in general.
>
> --
> Jeff Garzik
> exMULTI, Inc.
> jgarzik@exmulti.com
>
>
> ------------------------------------------------------------------------------
> Everyone hates slow websites. So do we.
> Make your web apps faster with AppDynamics
> Download AppDynamics Lite for free today:
> http://p.sf.net/sfu/appdyn_d2d_mar
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>

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Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">If you&#39;re considering a datagram protocol, you might b=
e interested in some more modern alternatives to UDP:<br><br>UDT: Breaking =
the Data Transfer Bottleneck<br><a href=3D"http://udt.sourceforge.net/">htt=
p://udt.sourceforge.net/</a><br>
<br>Stream Control Transmission Protocol<br><a href=3D"http://en.wikipedia.=
org/wiki/Stream_Control_Transmission_Protocol">http://en.wikipedia.org/wiki=
/Stream_Control_Transmission_Protocol</a><br><br></div><div class=3D"gmail_=
extra">
<br><br><div class=3D"gmail_quote">On Sat, Mar 23, 2013 at 12:17 AM, Jeff G=
arzik <span dir=3D"ltr">&lt;<a href=3D"mailto:jgarzik@exmulti.com" target=
=3D"_blank">jgarzik@exmulti.com</a>&gt;</span> wrote:<br><blockquote class=
=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padd=
ing-left:1ex">
Here is a rough draft implementation of a UDP P2P protocol extension<br>
for bitcoin:<br>
<br>
=C2=A0 =C2=A0 =C2=A0<a href=3D"https://github.com/jgarzik/bitcoin/tree/udp"=
 target=3D"_blank">https://github.com/jgarzik/bitcoin/tree/udp</a><br>
=C2=A0 =C2=A0 =C2=A0<a href=3D"http://yyz.us/bitcoin/udp-v0.patch" target=
=3D"_blank">http://yyz.us/bitcoin/udp-v0.patch</a><br>
<br>
Protocol specification (such that it is):<br>
<br>
- UDP, bound to same port as TCP P2P (normally 8333)<br>
- Active, simultaneous TCP P2P connection required (useful against DoS<br>
and other attacks)<br>
- Same message format as TCP P2P, same pchMessageStart conventions,<br>
etc. (my CNetMessage pull req would be helpful here)<br>
- Multiple P2P messages per UDP packet permitted<br>
- Max UDP packet size 100*1024 bytes<br>
- Advertises NODE_UDP in nServices<br>
- New &quot;getudpcook&quot; TCP P2P command returns a &quot;udpcook&quot; =
message,<br>
containing a yummy cookie<br>
- UDP P2P commands &quot;inv&quot;, &quot;tx&quot; and &quot;addr&quot; are=
 handled as if received via TCP<br>
- UDP P2P command &quot;udpsub&quot; sets a mask, that subscribes to one or=
 more<br>
data broadcasts.<br>
- When USM_INV_BCAST mask bit is set, receive &quot;inv&quot; messages via =
UDP<br>
rather than TCP.<br>
<br>
Project and design goals (or, why do this?):<br>
<br>
- It is theorized that UDP may be useful for some messages we<br>
broadcast throughout the network<br>
- A productive discussion STARTS with code, otherwise discussion<br>
continues forever.<br>
- Investigate improving &quot;inv&quot; relay speed<br>
- Investigate unconditional &quot;tx&quot; broadcasting via UDP, as &quot;i=
nv&quot;<br>
alternative, for small tx&#39;s.<br>
- Investigate improving block relay speed (or perhaps block header relay sp=
eed)<br>
- Open up new design avenues, for P2P patterns more suited to UDP than<br>
TCP in general.<br>
<br>
--<br>
Jeff Garzik<br>
exMULTI, Inc.<br>
<a href=3D"mailto:jgarzik@exmulti.com">jgarzik@exmulti.com</a><br>
<br>
---------------------------------------------------------------------------=
---<br>
Everyone hates slow websites. So do we.<br>
Make your web apps faster with AppDynamics<br>
Download AppDynamics Lite for free today:<br>
<a href=3D"http://p.sf.net/sfu/appdyn_d2d_mar" target=3D"_blank">http://p.s=
f.net/sfu/appdyn_d2d_mar</a><br>
_______________________________________________<br>
Bitcoin-development mailing list<br>
<a href=3D"mailto:Bitcoin-development@lists.sourceforge.net">Bitcoin-develo=
pment@lists.sourceforge.net</a><br>
<a href=3D"https://lists.sourceforge.net/lists/listinfo/bitcoin-development=
" target=3D"_blank">https://lists.sourceforge.net/lists/listinfo/bitcoin-de=
velopment</a><br>
</blockquote></div><br></div>

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