RFC 3082 (rfc3082) - Page 1 of 14


Notification and Subscription for SLP



Alternative Format: Original Text Document



Network Working Group                                           J. Kempf
Request for Comments: 3082                                J. Goldschmidt
Category: Experimental                                  Sun Microsystems
                                                              March 2001


                 Notification and Subscription for SLP

Status of this Memo

   This memo defines an Experimental Protocol for the Internet
   community.  It does not specify an Internet standard of any kind.
   Discussion and suggestions for improvement are requested.
   Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2001).  All Rights Reserved.

Abstract

   The Service Location Protocol (SLP) provides mechanisms whereby
   service agent clients can advertise and user agent clients can query
   for services.  The design is very much demand-driven, so that user
   agents only obtain service information when they specifically ask for
   it.  There exists another class of user agent applications, however,
   that requires notification when a new service appears or disappears.
   In the RFC 2608 design, these applications are forced to poll the
   network to catch changes.  In this document, we describe a protocol
   for allowing such clients to be notified when a change occurs,
   removing the need for polling.

1. Introduction

   The Service Location Protocol (SLP) [1] provides a mechanism for
   service agent (SA) clients to advertise network services and for user
   agent (UA) clients to find them.  The mechanism is demand-driven.
   UAs obtain service information by actively querying for it, and do
   not obtain any information unless they do so.  While this design
   satisfies the requirements for most applications, there are some
   applications that require more timely information about the
   appearance or disappearance in the services of interest.

   Ideally, these applications would like to be notified when a new
   service comes up or when a service disappears.  In order to obtain
   this information with SLP as described in RFC 2608, such applications
   must poll the network to periodically refresh their local cache of
   available service advertisements.



Kempf & Goldschmidt           Experimental