Apple NETWORK SERVICES Administrator Guide

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Network Services

Location Manager

Network administrator’s guide

This document describes the Network Services Location (NSL) Manager and provides
information on setting up a network to take advantage of its services. Read this document if you
are a network administrator or are responsible for setting up or managing network services.

What Is the NSL Manager?

Part of the Mac OS, NSL Manager is software that helps network services advertise themselves
and helps applications find advertised services on the network.

In the past, finding services on a TCP/IP network was difficult unless an administrator took
steps to list available services.

With the NSL Manager, network services advertise themselves and applications can find those
services. When an application asks it to locate a network service, the NSL Manager uses
standard protocols to find available services. Located services are grouped into network
“neighborhoods” based on such attributes as the network segment in which the services are
found and the service location protocols operating in that segment.

Which Computers Use the NSL Manager?

The NSL Manager is available on all computers with a PowerPC™ microprocessor and Mac OS 8.5
or later installed. Details vary with the version of the Mac OS.

NSL Manager 1.0 in Mac OS 8.5

In version 1.0 of the NSL Manager in Mac OS 8.5, each service location protocol is
implemented as a plug-in, an extension that makes itself available to the NSL Manager when
the NSL Manager is initialized, but resides in memory only when it is responding to a request.
You can use the Extensions Manager to enable and disable individual NSL plug-ins.

When the NSL Manager is initialized, each NSL plug-in tells it the types of services the plug-in
can search for, such as HTTP and FTP, and the protocol the plug-in uses to conduct searches,
such as DNS or LDAP.

When the NSL Manager receives a request to advertise or locate a network service, it passes
the request to a plug-in that performs the actual registration or search.

NSL Manager 1.1 in Mac OS 9

In Mac OS 9, NSL Manager version 1.1 functions as described for OS 8.5 and includes four
plug-ins: Domain Name Service (DNS), Service Location Protocol (SLP), Lightweight Directory
Access Protocol (LDAP), and Name Binding Protocol (NBP).

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