FOUNDATION FOR INTELLIGENT PHYSICAL AGENTS

 

 

                                Steve Willmott                             Ion Constantinescu

                        <willmott@lia.di.epfl.ch>                     <cion@lia.di.epfl.ch>

 

 Problem Statement: There have been numerous requests for FIPA to provide a standard means for agents to communicate with each other over the HTTP protocol. The following reasons are most commonly given to support this request:

·         HTTP or TCP/IP are often used in experimental agent systems and it would be very simple for these systems to upgrade to a FIPA specified HTTP MTP

·         HTTP is the basis for today’s explosive growth in Internet traffic and services and is likely to play a major role in the commercial deployment of agent technology

·         There exist a wide range of commercial and free implementations which not only handle HTTP traffic but provide considerable value added features such as:

o        Security and access control

o        Access logging and log file analysis

o        Interfaces to many types of backend system (including server side Java, ASP, scripted web pages and CGI programs in almost any language)

·         Lastly, there are still outstanding problems with the current FIPA IIOP MTP[1] (the current suggestion for use in wireline environments, see [FIPA00075]):

o        The need to exchange and refresh IORs instead of simply using URLs to address transport interfaces

o        Potentially heavyweight implementations (possibly requiring a CORBA ORB, naming services etc.)

o        A perception that IIOP is considerably more complex than HTTP or TCP/IP

 

These requirements urgently need to be addressed if FIPA Agent technology is to fulfil its potential in next generation Internet services. Communication over HTTP would make it easier for developers to unify existing web based services with new agent based components and potentially make FIPA technology considerably more attractive to new developers and users.

 

For agent message transport over HTTP to be viable, two key issues must be addressed:

·         Agreement on the precise version of HTP to use, on option and parameter settings and on conventions for usage (error messages etc.)

·         A representation for FIPA message transport envelope information.

 

Without these, agents would likely end up using diverse, ad-hoc combinations of HTTP version/information representation etc. which would preclude widespread interoperability.

Objective: The scope of this work plan is limited to producing two specifications documents to form part of the FIPA Agent Message Transport Specifications:

·         A specification for the use of HTTP as a FIPA Message Transport Protocol (MTP)

·         A specification for the representation of message transport envelope information (see [FIPA00067]) for use with the MTP

 

The aim is for these specifications to provide an alternative to current IIOP [FIPA00075] and WAP [FIPA00076] MTP specifications for developers seeking to develop agent systems with future web deployment in mind. The aim is not to replace the current MTP specifications but to complement them.

 

Technology: Preliminary drafts for both the MTP specification and the envelope specifications have been produced and can be found on-line at http://liawww.epfl.ch/~cion/acc. The proposed solutions can be summarised as follows:

·         The MTP specification is based on HTTP 1.1 with caching disabled and no requirement for persistent connections (although they are supported)

·         The envelope specification uses XML as a representation.

 

An open source implementation of both of these specifications using the standard Java Message Service (JMS) interface is also provided at http://liawww.epfl.ch/~cion/acc.

 

It is expected that the draft specifications will need to be modified following comments and input from other interested FIPA members.

           

Specifications Generated:  As stated under “Objectives”, the aim of this work plan is to produce two specifications:

·         A specification of the use of HTTP as a FIPA Message Transport Protocol (MTP)

·         A specification for the representation of message transport envelope information (see [FIPA00067]) for use with the MTP.

 

Plan for Work and Milestones: If accepted, the work plan would be carried out in the following way:

·         Reflector discussion: between now and the FIPA Baltimore meeting (July 2000)

·         New Versions of draft specifications: before the Baltimore meeting

·         Half day technical meeting: During the Baltimore meeting

·         Submission for Preliminary status: End of the Baltimore meeting

·         Submission for experimental status: As soon as possible after preliminary status has been reached (note that this step should be relatively quick since implementations already exist)

 

Future Work: Maintenance of the specification to ensure it continues to meet the needs of most developers wishing to use HTTP as a transport protocol.

 

Dependencies:

·         [FIPA00072] FIPA Agent Message Transport Envelope Representation Library. Updating the list of available MTPs.

·         [FIPA00074] FIPA Agent Message Transport Protocol Library. Updating the list of available envelope encodings.

 

Support:

·         Steve Willmott, EPFL

·         Jonathan Dale, Fujitsu Laboratories of America

·         Luis Bothelo, ADETTI

·         Bernard Burg, Motorola

 

 

 

FIPA Architecture Board response:

This work plan has been approved and has been assigned to the Transport Working Group.