ALTO Incremental Updates Using Server-Sent Events (SSE)

The information below is for an old version of the document
Document Type Expired Internet-Draft (alto WG)
Last updated 2018-01-04 (latest revision 2017-07-03)
Replaces draft-roome-alto-incr-update-sse
Stream IETF
Intended RFC status Proposed Standard
Expired & archived
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Stream WG state WG Document
Document shepherd Vijay Gurbani
IESG IESG state Expired
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


The Application-Layer Traffic Optimization (ALTO) [RFC7285] protocol provides network related information, called network information resources, to client applications so that clients can make informed decisions in utilizing network resources. For example, an ALTO server can provide network and cost maps so that an ALTO client can use the maps to determine the costs between endpoints when choosing communicating endpoints. However, the ALTO protocol does not define a mechanism to allow an ALTO client to obtain updates to the information resources, other than by periodically re-fetching them. Because some information resources (e.g., the aforementioned maps) may be large (potentially tens of megabytes), and because only parts of the information resources may change frequently (e.g., only some entries in a cost map), complete re-fetching can be extremely inefficient. This document presents a mechanism to allow an ALTO server to push updates to ALTO clients, to achieve two benefits: (1) Updates can be immediate, in that the server can send updates as soon as they are available; and (2) Updates are incremental, in that if only a small section of an information resource changes, the server can send just the changes.


Wendy Roome (
Y. Yang (

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