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