Application-Layer Traffic Optimization (ALTO) Problem Statement
RFC 5693
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RFC - Informational
(October 2009; No errata)
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Last updated |
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2015-10-14
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draft-marocco-alto-problem-statement
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IETF
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RFC 5693 (Informational)
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Unknown
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Responsible AD |
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Lisa Dusseault
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jon.peterson@neustar.biz
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Network Working Group J. Seedorf
Request for Comments: 5693 NEC
Category: Informational E. Burger
Neustar Inc.
October 2009
Application-Layer Traffic Optimization (ALTO) Problem Statement
Abstract
Distributed applications -- such as file sharing, real-time
communication, and live and on-demand media streaming -- prevalent on
the Internet use a significant amount of network resources. Such
applications often transfer large amounts of data through connections
established between nodes distributed across the Internet with little
knowledge of the underlying network topology. Some applications are
so designed that they choose a random subset of peers from a larger
set with which to exchange data. Absent any topology information
guiding such choices, or acting on suboptimal or local information
obtained from measurements and statistics, these applications often
make less than desirable choices.
This document discusses issues related to an information-sharing
service that enables applications to perform better-than-random peer
selection.
Status of This Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the BSD License.
Seedorf & Burger Informational [Page 1]
RFC 5693 ALTO Problem Statement October 2009
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. State-of-the-Art . . . . . . . . . . . . . . . . . . . . . 4
2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. The Problem . . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1. File sharing . . . . . . . . . . . . . . . . . . . . . . . 8
4.2. Cache/Mirror Selection . . . . . . . . . . . . . . . . . . 8
4.3. Live Media Streaming . . . . . . . . . . . . . . . . . . . 8
4.4. Real-Time Communications . . . . . . . . . . . . . . . . . 9
4.5. Distributed Hash Tables . . . . . . . . . . . . . . . . . 9
5. Aspects of the Problem . . . . . . . . . . . . . . . . . . . . 9
5.1. Information Provided by an ALTO Service . . . . . . . . . 9
5.2. ALTO Service Providers . . . . . . . . . . . . . . . . . . 10
5.3. ALTO Service Implementation . . . . . . . . . . . . . . . 10
5.4. User Privacy . . . . . . . . . . . . . . . . . . . . . . . 10
5.5. Topology Hiding . . . . . . . . . . . . . . . . . . . . . 11
5.6. Coexistence with Caching . . . . . . . . . . . . . . . . . 11
6. Security Considerations . . . . . . . . . . . . . . . . . . . 11
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 12
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12
9. Informative References . . . . . . . . . . . . . . . . . . . . 13
1. Introduction
1.1. Overview
Distributed applications, both peer-to-peer (P2P) and client/server
used for file sharing, real-time communication, and live and on-
demand media streaming, use a significant amount of network capacity
and CPU cycles in the routers [WWW.wired.fuel]. In contrast to
centralized applications, distributed applications access resources
such as files or media relays distributed across the Internet and
exchange large amounts of data in connections that they establish
directly with nodes sharing such resources.
One advantage of highly distributed systems results from the fact
that the resources such systems offer are often available through
multiple replicas. However, applications generally do not have
reliable information of the underlying network and thus have to
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