Application-Layer Traffic Optimization (ALTO) Protocol
RFC 7285
Internet Engineering Task Force (IETF) R. Alimi, Ed.
Request for Comments: 7285 Google
Category: Standards Track R. Penno, Ed.
ISSN: 2070-1721 Cisco Systems, Inc.
Y. Yang, Ed.
Yale University
S. Kiesel
University of Stuttgart
S. Previdi
Cisco Systems, Inc.
W. Roome
Alcatel-Lucent
S. Shalunov
Open Garden
R. Woundy
Comcast
September 2014
Application-Layer Traffic Optimization (ALTO) Protocol
Abstract
Applications using the Internet already have access to some topology
information of Internet Service Provider (ISP) networks. For
example, views to Internet routing tables at Looking Glass servers
are available and can be practically downloaded to many network
application clients. What is missing is knowledge of the underlying
network topologies from the point of view of ISPs. In other words,
what an ISP prefers in terms of traffic optimization -- and a way to
distribute it.
The Application-Layer Traffic Optimization (ALTO) services defined in
this document provide network information (e.g., basic network
location structure and preferences of network paths) with the goal of
modifying network resource consumption patterns while maintaining or
improving application performance. The basic information of ALTO is
based on abstract maps of a network. These maps provide a simplified
view, yet enough information about a network for applications to
effectively utilize them. Additional services are built on top of
the maps.
This document describes a protocol implementing the ALTO services.
Although the ALTO services would primarily be provided by ISPs, other
entities, such as content service providers, could also provide ALTO
services. Applications that could use the ALTO services are those
that have a choice to which end points to connect. Examples of such
applications are peer-to-peer (P2P) and content delivery networks.
Alimi, et al. Standards Track [Page 1]
RFC 7285 ALTO Protocol September 2014
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7285.
Copyright Notice
Copyright (c) 2014 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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction ....................................................6
1.1. Problem Statement ..........................................6
1.1.1. Requirements Language ...............................7
1.2. Design Overview ............................................7
2. Terminology .....................................................7
2.1. Endpoint ...................................................8
2.2. Endpoint Address ...........................................8
2.3. Network Location ...........................................8
2.4. ALTO Information ...........................................8
2.5. ALTO Information Base ......................................8
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