SLP(4P) Protocols SLP(4P)

NAME

slp - Service Location Protocol

DESCRIPTION

The Service Location Protocol (SLP) is a dynamic service discovery
protocol that runs on top of the Internet Protocol (IP). The protocol
is specified by the IETF standard-track documents RFC 2165, RFC
2608, RFC 2609; the API is documented in RFC 2614. .


There are two components to the SLP technology. The first is a
daemon, slpd(8), which coordinates SLP operations. The second is a
software library, slp_api(3SLP), through which processes access a
public API. Both components are configured by means of the SLP
configuration file, slp.conf(5).


The SLP API is useful for two types of processes:

Client Applications
Services and service information can be
requested from the API. Clients do not need
to know the location of a required service,
only the type of service, and optionally, the
service characteristics. SLP will supply the
location and other information to the client
through the API.


Server Processes
Programs that offer network services use the
SLP API to advertise their location as well as
other service information. The advertisement
can optionally include attributes describing
the service. Advertisements are accompanied by
a lifetime; when the lifetime expires, the
advertisement is flushed, unless it is
refreshed prior to expiration.


API libraries are available for both the C and Java languages.


SLP provides the following additional features:

o slpd(8) can be configured to function as a transparent
directory agent. This feature makes SLP scalable to the
enterprise. System administrators can configure directory
agents to achieve a number of different strategies for
scalability.

o SLP service advertising and discovery is performed in
scopes. Unless otherwise configured, all discovery and all
advertisements are in the scope default. In the case of a
larger network, scopes can be used to group services and
client systems so that users will only find those services
which are physically near them, belong to their
department, or satisfy the specified criteria.
Administrators can configure these scopes to achieve
different service provider strategies.

o Services may be registered by proxy through a serialized
registration file. This is an alternative to registering
services through the API. See slpd.reg(5) for more
information.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|CSI | CSI-enabled |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+

SEE ALSO

slp_api(3SLP), slp.conf(5), slpd.reg(5), attributes(7), slpd(8)


Guttman, E., Perkins, C., Veizades, J., and Day, M., RFC 2608,
Service Location Protocol, Version 2, The Internet Society, June
1999.


Guttman, E., Perkins, C., and Kempf, J., RFC 2609, Service Templates
and Service: Schemes, The Internet Society, June 1999.


Kempf, J. and Guttman, E., RFC 2614, An API for Service Location, The
Internet Society, June 1999.


Veizades, J., Guttman, E., Perkins, C., and Kaplan, S., RFC 2165,
Service Location Protocol, Network Working Group, 1997.

November 17, 1999 SLP(4P)