Advertisement and Discovery of Services (ADS)

Web services directories accessible to both application developers and
applications will be central pieces of the future B2B infrastructure,
in much the same way as business directories are critical pieces of
today's economies. New standards will emerge to provide universal
access to the directories, and most businesses will register their
information with well known directory service providers. The
transition to this new infrastructure will have to take place at many
different levels and at different times.

This document deals with the problem of how to effectively enable the
emergence of B2B directories using existing Web infrastructure, and
aims at outlining the path for a smooth transition between today's
user-centric Web and a new business-enabled one. The starting point is
thus the current HTML oriented Web, while the (moving) target is the
future services directory infrastructure. The connection between the
two is achieved using XML descriptions of service interfaces.

The proposal contained in this document describes a simple mechanism
by which a Web server can become a read-only directory advertising its
own services, thus enabling discovery of services by B2B search
engines. The proposed mechanism uses existing HTML pages to aid in the
location of XML descriptions of business services. It introduces a
basic HTTP discovery protocol, but architects an extension mechanism
that uses WSDL documents to allow flexible integration with upcoming
directory standards.