RFC 9275

An Extension for Application-Layer Traffic Optimization (ALTO): Path Vector, September 2022

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K. Gao
Y. Lee
S. Randriamasy
Y. Yang
J. Zhang
alto (ops)

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DOI:  https://doi.org/10.17487/RFC9275

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This document is an extension to the base Application-Layer Traffic Optimization (ALTO) protocol. It extends the ALTO cost map and ALTO property map services so that an application can decide to which endpoint(s) to connect based not only on numerical/ordinal cost values but also on fine-grained abstract information regarding the paths. This is useful for applications whose performance is impacted by specific components of a network on the end-to-end paths, e.g., they may infer that several paths share common links and prevent traffic bottlenecks by avoiding such paths. This extension introduces a new abstraction called the "Abstract Network Element" (ANE) to represent these components and encodes a network path as a vector of ANEs. Thus, it provides a more complete but still abstract graph representation of the underlying network(s) for informed traffic optimization among endpoints.

For the definition of Status, see RFC 2026.

For the definition of Stream, see RFC 8729.

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