Inside Macintosh: Networking /

Chapter 10 - Link-Access Protocol (LAP) Manager

The Link-Access Protocol (LAP) Manager is a set of operating-system utilities that provide a standard interface between the higher-level AppleTalk protocols and the various link-access protocols, such as LocalTalk (LLAP), EtherTalk (ELAP), TokenTalk (TLAP), and FDDITalk (FLAP). This chapter describes the LAP Manager programming interfaces to the AppleTalk Transition Queue and the 802.2 packet protocol handlers only. This chapter does not discuss the LAP Manager interface to AppleTalk connection files of type 'adev' that comprise the data links. Apple Computer, Inc. recommends that you not write your own 'adev' files. However, for a description of the LAP Manager that includes the interface to AppleTalk connection files for EtherTalk and other AppleTalk connections, see the Macintosh AppleTalk Connections Programmer's Guide.

You should read this chapter if you want the LAP Manager to notify you when a transition occurs or is about to occur. An AppleTalk transition is an event, such as an AppleTalk driver being opened or closed, that can affect your AppleTalk application. This chapter also describes how you can define a transition to notify other applications of a transition event that your application effects.

You should also read this chapter if your application processes 802.2 Type 1 packets. In this case, you must write a protocol handler that reads 802.2 Type 1 data packets and install your protocol handler as a client of the LAP Manager.

For an overview of the LAP Manager and how it fits within the AppleTalk protocol stack, read the chapter "Introduction to AppleTalk" in this book, which also introduces and defines some of the terminology used in this chapter. For additional information on the IEEE 802.2 standard, see Inside AppleTalk, second edition.

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Chapter Contents

About the LAP Manager

Using the LAP Manager

Determining if the LAP Manager Is Installed

Adding an Entry to the AppleTalk Transition Queue

How the LAP Manager Calls Your Transition Event Handler Routine

Writing a Transition Event Handler Routine Using Pascal

Open Transition

Prepare-to-Close Transition

Permission-to-Close Transition

Cancel-Close Transition

Network-Connection-Change Transition

Flagship-Name-Change Transition

Permission-to-Change-Flagship-Name Transition

Cancel-Flagship-Name-Change Transition

Cable-Range-Change Transition

CPU-Speed-Change Transition

Developer-Defined Transitions

Defining Your Own AppleTalk Transition

The LAP Manager and 802.2 Protocol Packets

Attaching and Detaching 802.2 Protocol Handlers

LAP Manager Reference

Data Structures

The AppleTalk Transition Queue Entry

Routines

Adding and Removing AppleTalk Transition Queue Entries

Notifying Routines When Your Application-Defined Transition Occurs

Attaching and Detaching 802.2 Protocol Handlers

Summary of the LAP Manager

Pascal Summary

Constants

Data Types

AppleTalk Transition Queue Entry

Routines

Adding and Removing AppleTalk Transition Queue Entries

Notifying Routines When Your Application-Defined Transition Occurs

C Summary

Constants

Data Types

AppleTalk Transition Queue Entry

Routines

Adding and Removing AppleTalk Transition Queue Entries

Notifying Routines When Your Application-Defined Transition Occurs

Assembly-Language Summary

Constants

Data Structures

AppleTalk Transition Queue Entry Data Structure

Result Codes