Internet Engineering Task Force P. Crowley Internet Draft Washington University Intended status: Informational July 7, 2008 Expires: January 1, 2009 On the Relative Importance of P2P Peer Selection draft-crowley-alto-importance-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html This Internet-Draft will expire on January 1, 2009. Copyright Notice Copyright (C) The IETF Trust (2008). Abstract This Internet-draft discusses the relative importance of path selection in peer-to-peer (P2P) applications. Recent discussions have highlighted the conflict between the use of P2P applications and the costs borne by network infrastructure operators. We conclude that it Crowley Expires January 1, 2009 [Page 1] Internet-Draft Relative Importance of Path Selection July 2008 would be premature for the IETF to strongly pursue standardization in this area. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC-2119 [1]. Table of Contents 1. Introduction...................................................2 1.1. Error! Bookmark not defined. 2. Context & Importance...........................................2 2.1. Technical Strengths.......................................3 3.
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..Error! Bookmark not defined. 5. Formal Syntax.......................Error! Bookmark not defined. 6. Security Considerations........................................5 7. IANA Considerations............................................5 8. Conclusions....................................................5 9. Acknowledgments................................................5 10. Informative References........................................5 Author's Addresses................................................5 Intellectual Property Statement...................................6 Disclaimer of Validity............................................6 1. Introduction The purpose of this document is to juxtapose P2P context, importance, problems with solutions offered by standards. In particular, the goal is to explore whether the current challenges created by peer-to-peer applications can be effectively solved, or at least ameliorated, through standardization efforts. 2. Context & Importance P2P is a huge consumer traffic source[1,2]. The dominant use is for file-sharing; streaming video is significant in some parts of the world. Clearly P2P file sharing is an important application for users and infrastructure owners. It is also mostly criminal (blatant theft or civil disobedience?). Crowley Expires January 1, 2009 [Page 2] Internet-Draft Relative Importance of Path Selection July 2008 This is an unwieldy conversation because many topics are grouped together, but specific problems and solutions typically apply to a single topic: o BitTorrent o File Sharing o Video on Demand o Voice & Instant Messaging o Peer-to-Peer v. Client-Server 2.1. Technical Strengths Effectively eliminates costs associated with distributing large digital files. Individuals with consumer DSL connections can be global-scale publishers of multi-gigabyte files. Deploys and changes at the rate of change of end-user habits. Low friction for develoment and deployment. There are no encumbrances from service or infrastructure providers to slow things down. Scales automatically with available resources, because it does not require manual intervention to utilize capacity increases. 3. Problems with P2P Applications Home users: - interference with latency apps (Shalanuv's comments on buffers in home routers) Tends to fill buffers along paths, so all latency- sensitive apps sharing the path will suffer. - can exhaust bandwidth caps ISPs: large bw usage, usage scales w/capacity, not bursty but steady, large, and long-lasting - problem due to the conjunction of these three. For example, FTP is also steady, large, and long-lasting but no one uses it. - technical problems or business model problems? Crowley Expires January 1, 2009 [Page 3] Internet-Draft Relative Importance of Path Selection July 2008 4. Proposed Solutions Localization, Caching, hybrid server-peer architecturs, Traffic Shaping ALTO is particularly concerned with mechanisms used to select peers. Mechanisms are nicely surveyed in ALTO abstract, where two major approaches are summarized: end-to-end measurement and application-to- network layer cooperation. These peer selection ideas are only useful in contexts where peers are abundant and many options of equivalent quality exist. 5. Problems Solved via Standardization What Problems do Standards Solve? Avoid the problems associated with a single solution provider, such as monopoly pricing power and technical frailty, by encouraging commodification of the object of standardization. Avoid the problems associated with the reinvention and fragmentation of common solutions: safety (reduce likelihood of errors and mistakes), interoperability, and quality. No shortage of feasible technical solutions, but effectiveness determined by business models and end-user willingness. Examples - Fixed prices with bandwidth caps. - Pay-per-bit - Traffic categories, per-category pricing model Current user vocabulary is phone, video, and data. Obvious and clear to consumer customers of telephone and cable companies. Is the Internet a utility, infrastructure, or a service platform? Utility: Electricity - Charged for kwH used, doesn't matter what they are used for Infrastructure: Roads - Does not produce profit directly, but enables profitable uses. Crowley Expires January 1, 2009 [Page 4] Internet-Draft Relative Importance of Path Selection July 2008 Service platform: mobile phones - Seperate voice, data, and SMS pricing models. 6. Security Considerations Security risks tend to increase with complexity. Any proposal that increases the complexity of infrastructure or interfaces invites the risk of complicating security. More specifically, if a service provider publishes information that is meant to bowl improve user performance and reduce service provider cost, there will always be the opportunity for subversion, or perhaps the more insidious suspicion that the service provider is paying greater attention to its costs than to the performance provided. An effective antidote for this situation is independent verification. 7. IANA Considerations 8. Conclusions In conclusion, because standardization seems ill-positioned to address the most pressing problems with peer-to-peer systems, it is likely premature for the IETF to pursue any strong activities in standardization. 9. Acknowledgments This document was prepared using 2-Word-v2.0.template.dot. 10. Informative References [1] Cisco Systems, "Cisco Visual Networking Index-Forecast and Methodology, 2007-2012", White Paper, http://www.cisco.com, June 2008. [2] Cisco Systems, "Approaching the Zettabyte Era", White Paper, http://www.cisco.com, June 2008. Crowley Expires January 1, 2009 [Page 5] Internet-Draft Relative Importance of Path Selection July 2008 Author's Addresses Patrick Crowley Washington University Dept. of CSE/Campus Box 1045 One Brookings Drive St. Louis, MO 63130 USA Email: pcrowley@wustl.edu URL: http://www.arl.wustl.edu/~pcrowley Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. 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Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Crowley Expires January 1, 2009 [Page 6] Internet-Draft Relative Importance of Path Selection July 2008 Copyright Statement Copyright (C) The IETF Trust (0000). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Crowley Expires January 1, 2009 [Page 7]