Application-Layer Traffic Optimization (ALTO) Performance Cost Metrics
RFC 9439

Received changes through RFC Editor sync (created alias RFC 9439, changed title to 'Application-Layer Traffic Optimization (ALTO) Performance Cost Metrics', changed abstract to 'The cost metric is a basic concept in Application-Layer Traffic
Optimization (ALTO), and different applications may use different
types of cost metrics. Since the ALTO base protocol (RFC 7285)
defines only a single cost metric (namely, the generic "routingcost"
metric), if an application wants to issue a cost map or an endpoint
cost request in order to identify a resource provider that offers
better performance metrics (e.g., lower delay or loss rate), the base
protocol does not define the cost metric to be used.

This document addresses this issue by extending the specification to
provide a variety of network performance metrics, including network
delay, delay variation (a.k.a. jitter), packet loss rate, hop count,
and bandwidth.

There are multiple sources (e.g., estimations based on measurements
or a Service Level Agreement) available for deriving a performance
metric. This document introduces an additional "cost-context" field
to the ALTO "cost-type" field to convey the source of a performance
metric.', changed pages to 35, changed standardization level to Proposed Standard, changed state to RFC, added RFC published event at 2023-08-11, changed IESG state to RFC Published)