Subject: Service Discovery (was The IETF's "Next Step" ?)

From: Erik Guttman <[email-masked]>
Date: Mon, 12 Oct 1998 19:08:22 +0200

Jim Fleming wrote, Mon, 5 Oct 1998 08:38:44 -0500
> Fred,
> 
> Is the "protocol" work described below part of the IETF ?
> If not, where would it fit ?
> 

The protocol described below is indeed close to the Service 
Location Protocol, or SLP (RFC 2165).  It does differ in 
several important respects:

  . It is not an IETF protocol.  It is has not been worked on
    in the framework of a standards organization.
  . It is a Java-centric solution to the service discovery,
    automatic application configuration and decentralized 
    administration problem.  SLP is language neutral.
  . Jini's lookup protocol allows clients to retrieve service
    objects.  SLP retrieves service locations in the form of
    URLs.
  . Jini models services using Java objects.  SLP models
    the characteristics of services using string encoded
    attributes in the same form as LDAPv3.

Services which register to SLP can be proxy registered into
a Jini Lookup service.  This is indeed the strategy which 
Sun is embracing.  I know this since I am the WG chair for
SVRLOC and I work at Sun, with the Jini team.    

> @@@@ http://www.wired.com/wired/6.08/jini.html
> 
> "On top is a directory service, based on a "lookup" mechanism
> that allows different Jini-enabled devices and applications to
> register and be seen on the network. The next-level service is
> persistence, provided by JavaSpaces technology, which stores
> objects so that other users or applications can retrieve them.
> Below that, a set of protocols based on Java's Remote Method
> Invocation enables objects to communicate and pass each other
> code. And finally a boot, join, and discover protocol allows
> Jini-compatible devices, users, and applications to announce
> themselves to the network and register in a directory."
> 

Jini provides object oriented mechanisms to interact with 
remote services and systems.  This is quite different than
SLP which provides string based directory-like operations
and initial discovery, only.

> @@@@@@@@@@@@@@@@@@@@@@@
> 
> 
> In your recent meeting with Eric Schmidt of Novell, did
> he mention this work ? I assume that you are aware that
> Eric used to be with Sun.

I used to work in Eric Schmidt's organization at Sun.  He was very
supportive of the SLP standardization effort.  Novell has also
embraced SLP, which replaces the Service Advertising Protocol
(SAP) in their IP implementation of Netware 5.0.

> How does the IETF and the IAB plan to keep up with
> the pace in these areas ?....or does it care ?
> 

The IETF certainly does care, and has set the pace in this area.

Erik Guttman

> Jim Fleming