Subject: [alto] I-D Action: draft-ietf-alto-protocol-11.txt

From: [email-masked]
Date: Sun, 11 Mar 2012 17:19:59 -0700

A New Internet-Draft is available from the on-line Internet-Drafts directories. This draft is a work item of the Application-Layer Traffic Optimization Working Group of the IETF.

	Title           : ALTO Protocol
	Author(s)       : Richard Alimi
                          Reinaldo Penno
                          Y. Richard Yang
	Filename        : draft-ietf-alto-protocol-11.txt
	Pages           : 68
	Date            : 2012-03-11

   Networking applications today already have access to a great amount
   of Inter-Provider network topology information.  For example, views
   of the Internet routing table are easily available at looking glass
   servers and entirely practical to be downloaded by clients.  What is
   missing is knowledge of the underlying network topology from the ISP
   or Content Provider (henceforth referred as Provider) point of view.
   In other words, what a Provider prefers in terms of traffic
   optimization -- and a way to distribute it.

   The ALTO Service provides network information (e.g., basic network
   location structure, preferences of network paths) with the goal of
   modifying network resource consumption patterns while maintaining or
   improving application performance.  The basic information of ALTO is
   based on abstract maps of a network.  These maps provide simplified,
   yet enough information of a network for applications to effectively
   utilize.  Additional services are built on top the maps.

   This document describes a protocol implementing the ALTO Service.
   Although the ALTO service would primarily be provided by the network
   (i.e., the ISP), content providers and third parties could also
   operate this service.  Applications that could use this service are
   those that have a choice in connection endpoints.  Examples of such
   applications are peer-to-peer (P2P) and content delivery networks.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-alto-protocol-11.txt

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

This Internet-Draft can be retrieved at:
ftp://ftp.ietf.org/internet-drafts/draft-ietf-alto-protocol-11.txt

---

From: Richard Alimi <[email-masked]>
Date: Sun, 11 Mar 2012 17:21:23 -0700

Hi All,

We have submitted an update to the ALTO Protocol draft which addresses
the outstanding items from the last IETF and the couple of discussions
on the list.

The main portions of the protocol have remained relatively stable for
quite a while now, so it would be good to look towards wrapping this
up.  Based on recent activity, I know folks are already looking
towards how we want to extend it.

The changes in this version are:
- Removed the section on redistribution (since some of the mechanism
there may eventually be provided by the JOSE WG).  The intent is to
submit that as a separate draft, but that isn't done yet.

- Removed the Server Information Service, since its only existing
purpose was to carry certificates used in the now-removed
redistribution mechanism.  It didn't seem worthwhile to have an
interface in the base protocol that was entirely unused, and it was
independent from everything else and thus would fit well in a separate
document. However, I'd be happy to add that back if the WG feels like
we should have that in the base protocol.  Discuss :)

- Added an explicit note that costs in the cost map are end-to-end
costs.  Let us know if the added text still does not make the
semantics clear.

- Changed the data type of costs from JSONNumber to JSONValue in the
formal specification. Implementations are required to use this as
JSONNumber unless an extension document indicates that something else
is permitted (and that extension document should indicate when and how
to do this without breaking existing implementations).  This was
provided as an extension hook for cost values that are not numbers.
If there are ideas for how this text could be refined, that would be
great.

- Added greater than or equal to, less than or equal to, and equal to
operators to constraints.

- Added an explicit note to caution clients against constraints
applied to ordinal cost maps.  Based on Bill's thread "What do
constraints mean for ordinal costs?", the cleanest solution seemed to
be to indicate that cost constraints shouldn't pertain to ordinal cost
maps. Looking at this again, it seemed unnecessarily-constraining to
forbid it (meaning, it would be an error to do so), but there is now a
note indicating why clients may not get what they asked for.  If that
isn't sufficient, please let us know.

Thanks!
Rich