Multi-Cost ALTO

Document Type Replaced Internet-Draft (individual)
Authors Sabine Randriamasy  , Wendy Roome  , Nico Schwan 
Last updated 2015-03-09
Replaced by RFC 8189
Stream (None)
Intended RFC status (None)
Expired & archived
plain text htmlized pdfized bibtex
Stream Stream state (No stream defined)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Replaced by draft-ietf-alto-multi-cost
Telechat date
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active.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


IETF is designing a new service called ALTO (Application Layer traffic Optimization) that includes a "Network Map Service", an "Endpoint Cost Service" and an "Endpoint (EP) Ranking Service" and thus incentives for application clients to connect to ISP preferred Endpoints. These services provide a view of the Network Provider (NP) topology to overlay clients. The present draft proposes a simple way to extend the information provided by the current ALTO protocol in two ways. First, including information on multiple Cost Types in a single ALTO transaction provides a better mapping of the Selected Endpoints to needs of the growing diversity of Content and Resources Networking Applications and to the network conditions. Second, one ALTO query and response exchange on N Cost Types is faster and more efficient than N single cost transactions. All this also helps producing a faster and more robust choice when multiple Endpoints need to be selected. Last, the draft proposes to enrich the filtering capabilities by allowing constraints involving several metrics combined by several types of logical operators. This allows the applications to set finer requirements and above all to include compromises on those requirements.


Sabine Randriamasy (
Wendy Roome (
Nico Schwan (

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