-\documentclass[conference]{IEEEtran}
+\documentclass{sig-alt-release2}
\usepackage[noadjust]{cite}
-
-\usepackage[dvips]{graphicx}
-
\usepackage{url}
-\usepackage[cmex10]{amsmath}
-\interdisplaylinepenalty=2500
-\usepackage{threeparttable}
-\usepackage{multirow}
+\hyphenation{dis-tri-bu-ted}
\begin{document}
+\conferenceinfo{SIGCOMM'08,} {August 17--22, 2008, Seattle, Washington, USA.}
+\CopyrightYear{2008}
+\crdata{978-1-60558-175-0/08/08}
+
\title{Leveraging Altruistic Peers to Reduce the Bandwidth Costs of Free Content Downloads}
-\author{\IEEEauthorblockN{Cameron Dale}
-\IEEEauthorblockA{School of Computing Science (student)\\
-Simon Fraser University\\
-Burnaby, British Columbia, Canada\\
-Email: camerond@cs.sfu.ca}
-\and
-\IEEEauthorblockN{Jiangchuan Liu}
-\IEEEauthorblockA{School of Computing Science (faculty)\\
-Simon Fraser University\\
-Burnaby, British Columbia, Canada\\
-Email: jcliu@cs.sfu.ca}}
+\numberofauthors{2}
+\author{
+\alignauthor Cameron Dale\\
+ \affaddr{School of Computing Science (student)}\\
+ \affaddr{Simon Fraser University}\\
+ \affaddr{Burnaby, British Columbia, Canada}\\
+ \email{Email: camerond@cs.sfu.ca}
+%\and
+\alignauthor Jiangchuan Liu\\
+ \affaddr{School of Computing Science (faculty)}\\
+ \affaddr{Simon Fraser University}\\
+ \affaddr{Burnaby, British Columbia, Canada}\\
+ \email{Email: jcliu@cs.sfu.ca}
+}
\maketitle
+\begin{abstract}
+We introduce the opportunity many free content distributors have to
+reduce their bandwidth costs using a peer-to-peer download
+mechanism. Our model for this peer-to-peer distribution is simple to
+implement, backwards-compatible with the existing infrastructure,
+and can be deployed incrementally. It makes wide use of a customized
+distributed hash table (DHT) to facilitate the finding of peers and
+the efficient downloading of files. We also present the example
+solution we created for one of these distributors, the Debian
+project, which is already in use by some users.
+\end{abstract}
+
+% A category with the (minimum) three required fields
+%\category{H.4}{Information Systems Applications}{Miscellaneous}
+%A category including the fourth, optional field follows...
+\category{C.2.4}{Computer-Communication Networks}{Distributed Systems}[Distributed applications]
+\terms{Design, Performance, Reliability}
+\keywords{BitTorrent, P2P}
+
\section{Introduction}
\label{intro}
been well-used to address this problem.
We present a new peer-to-peer distribution model to meet these
-demands. It is based on the lessons learned from many previous
-implementations of successful peer-to-peer protocols, such as
+demands, based on other successful peer-to-peer protocols such as
Distributed Hash Tables and BitTorrent.
The model relies on the pre-existence of cryptographic
hashes of the content, which uniquely identify it for a request from
containing software packages for the PERL programming language,
using SOAP RPC requests to find and download files; Cygwin provides
many of the standard Unix/Linux tools in a Windows environment,
-using a package management tool that requests packages from
+using a package management tool that requests \texttt{tar} files from
websites; two software distribution systems exist for Mac OSX,
fink and MacPorts, that also retrieve packages in this way. Also,
some systems use direct web downloads, but with a hash verification
-file also available for download next to the desired file. These
+file also available. These
hash files usually have the same file name, but with an added
extension identifying the hash used (e.g. \texttt{.md5} for the MD5
hash). Finally, there are other programs that make use of
fallback to downloading from the original content location, and once
complete will announce to other peers indicating that it now has
the content. The original servers or mirrors thus act as \emph{seeds} for the
-P2P system without any modification to them.
+P2P system without any modification to them, and users are satisfied even when
+there are no peers which allows the system to be deployed incrementally.
This functionality could be directly integrated into the
package management software, although this would be
difficult as the protocol should be running at all times, whereas the
package software typically only runs until the download request is complete.
-Alternatively, since many of the package management software
-implementations use HTTP requests to download the files, it
-it possible to implement the P2P aspect as as HTTP caching
+Alternatively, it
+it possible to implement the P2P aspect as a caching
proxy. The proxy will get uncached requests first from the P2P system,
-and then fallback to the normal HTTP request from a server. For
-methods that don't use HTTP requests, other types of proxies
-(possibly custom-made) may also be possible.
+and then fallback to the normal request from a server.
The sparse interest in a large
number of packages undergoing constant updating is well suited to
created a sample implementation called \texttt{apt-p2p} which
interacts with the \texttt{apt} tool found in most Debian-based
Linux distributions. \texttt{apt} uses SHA1 hashes to verify most
-downloaded files, including the large index files that contain
+downloaded files, including the large index files that contains detailed
information such as the hashes of the individual packages. Since all
requests from \texttt{apt} are in the form of HTTP downloads from a
server, the implementation takes the form of a caching HTTP proxy.
and TCP port), as well as the piece strings (or hashes of piece
strings) as described in the previous section. Downloading is
accomplished by simple HTTP requests for the hash of the file,
-which is sent to the peers identified from the DHT lookup to
+which is sent to the peers identified in a DHT lookup to
have the desired file. All peers support HTTP/1.1, both as
servers and clients, which allows for pipelining of multiple
requests to a peer, and the requesting of smaller pieces of a large
more widely used, we plan to collect more usage information on the
system through crawls and data analysis.
-\bibliographystyle{IEEEtran}
-\bibliography{./IEEEabrv,./all}
+\bibliographystyle{abbrv}
+\bibliography{./all}
\end{document}
projects / quix0rs-apt-p2p.git / blobdiff