ALTO Extension: Path Vector Cost Type

Document Type Expired Internet-Draft (alto WG)
Last updated 2019-01-03 (latest revision 2018-07-02)
Replaces draft-yang-alto-path-vector
Stream IETF
Intended RFC status (None)
Expired & archived
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Stream WG state WG Document
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IESG IESG state Expired
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The Application-Layer Traffic Optimization (ALTO) protocol [RFC7285] has defined cost maps and endpoint cost maps to provide basic network information. However, they provide only scalar (numerical or ordinal) cost mode values, which are insufficient to satisfy the demands of solving more complex network optimization problems. This document introduces an extension to the base ALTO protocol, namely the path-vector extension, which allows ALTO clients to query information such as capacity regions for a given set of flows. A non-normative example called multi-flow scheduling is presented to illustrate the limitations of existing ALTO endpoint cost maps. After that, details of the extension are defined.


Greg Bernstein (
Shiwei Chen (
Kai Gao (
Young Lee (
Wendy Roome (
Michael Scharf (
Yang Yang (
J. Zhang (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)