ALTO Cost Calendar

The information below is for an old version of the document
Document Type Expired Internet-Draft (alto WG)
Authors Sabine Randriamasy  , Y. Yang  , Qin Wu  , Deng Lingli  , Nico Schwan 
Last updated 2018-06-11 (latest revision 2017-12-08)
Stream Internet Engineering Task Force (IETF)
Expired & archived
pdf htmlized bibtex
Additional Resources
- Mailing list discussion
Stream WG state WG Consensus: Waiting for Write-Up (wg milestone: Jul 2020 - Submit cost property... )
Doc Shepherd Follow-up Underway
Document shepherd Vijay Gurbani
IESG IESG state Expired
Consensus Boilerplate Unknown
Telechat date
Responsible AD (None)
Send notices to Vijay Gurbani <>

This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


The goal of Application-Layer Traffic Optimization (ALTO) is to bridge the gap between network and applications by provisioning network related information in order to allow applications to make network informed decisions. The present draft extends the ALTO cost information so as to broaden the decision possibilities of applications to not only decide 'where' to connect to, but also 'when'. This is useful to applications that need to schedule their data transfers and connections and have a degree of freedom to do so. ALTO guidance to schedule application traffic can also efficiently help for load balancing and resources efficiency. Besides, the ALTO Cost Calendar allows to schedule the ALTO requests themselves and thus to save a number of ALTO transactions. This draft proposes new capabilities and attributes on filtered cost maps and endpoint cost maps enabling an ALTO Server to provide "Cost Calendars". These capabilities are applicable to ALTO metrics with time-varying values. With ALTO Cost Calendars, an ALTO Server exposes ALTO cost values in JSON arrays where each value corresponds to a given time interval. The time intervals as well as other Calendar attributes are specified in the IRD and ALTO Server responses.


Sabine Randriamasy (
Y. Yang (
Qin Wu (
Deng Lingli (
Nico Schwan (

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