Subject: Service Discovery on Internet

From: "RFelix" <[email-masked]>
Date: Thu, 21 Oct 1999 10:51:14 +0100

Dear SVRLOC WG members,

I've been studying SLP and i have the following question:

 Besides ADs, scopes are the main mechanism for scaling SLP. However the
definition of groups of services
is free and I understand that this task can be easy to do in enterprise
networks. What I consider difficult is how
can I define scopes in services on the Internet, in a wide-area network that
doesn't have a common administration,
with plenty of heterogeneous services and users?

thanks in advance,
Rui Pereira

---

From: Erik Guttman <[email-masked]>
Date: Thu, 21 Oct 1999 12:40:13 +0200 (MET DST)

> with plenty of heterogeneous services and users?

The applicability statement for SLP is that it is used in a network
with common administration.  SLP is not a wide-area service discovery
protocol.  Wide-area service discovery is an unsolved problem, but
you could say there are a number of different ways that it is done,
with some degree of success:

 - centralized directories (either formal, like a listing of all
   universities, from which you can access individual directories,
   or informal, as based on a random collection of web page links)
 - well known servers participating in a mesh (like IRC)
 - guesswork with common names (www.<some company>.com)
 - search engines (hit or miss)

None of this is particularly satisfying or answers the real need
which is that there should be some mechanism for finding services that
really exist (not just that have an entry in some directory) in the
Internet.  

We held a BOF on this at IETF 41 and there are extensive notes at the 
following URL:

  http://www.bell-labs.com/mailing-lists/wasrv/

In particular, I draw your attention to a requirements draft which
I coauthored, at:

  http://www.cs.columbia.edu/~jdrosen/papers/draft-rosenberg-wasrv-arch-00.txt

Erik