Inside Macintosh: Networking /

Preface - About This Book

This book, Inside Macintosh: Networking, describes the AppleTalk protocols and the application programming interfaces to them. AppleTalk is a network system including hardware and software that supports communication over
a variety of data-link types. Using AppleTalk, applications and processes can transfer and exchange data and share resources. The central part of the AppleTalk software consists of a number of protocols arranged in layers, with each protocol offering different services.

To familiarize you with the functions that each of these protocols provide so that you can determine which protocols to use for your application, this book includes an overview of the AppleTalk protocols. This book describes how
to write a networked application that uses the AppleTalk application programming interfaces to send and receive data. It describes how to use different methods to send data, such as establishing a sustained connection across which you can transfer streams of data or transferring data in small, discrete units called packets.

To gain an understanding of AppleTalk as a whole and a perspective of the types of services that each AppleTalk protocol provides, see the chapter "Introduction to AppleTalk." This chapter explains some basic networking concepts and how they apply to AppleTalk. It describes how addressing is implemented in AppleTalk networks and how this affects your application. It also explains how you can use each of the AppleTalk protocols for specific application requirements, and finally, it discusses a feature that is common to all routines across AppleTalk protocol interfaces: how to use either of two methods, synchronous or asynchronous, to specify when control is returned to your program after you call a routine.

To learn how to obtain information about the AppleTalk drivers and the networking environment and how to send packets to other applications and processes on your own node, see the chapter "AppleTalk Utilities."

To determine how to register your application with AppleTalk so that it
is visible on the network and available for other applications and processes
to contact and also how to obtain the addresses of other applications and processes so that you can contact them, see the chapter "Name-Binding Protocol (NBP)."

To obtain zone location information for the node that is running your applica-
tion or other applications on an AppleTalk network, see the chapter "Zone Information Protocol (ZIP)."

To provide support for a networked application that establishes and maintains a peer-oriented session connection between your application and its partner on the network and that allows the applications to send streams of data to each other, see the chapter "AppleTalk Data Stream Protocol (ADSP)." This chapter also discusses how you can establish a secure connection that provides for user authentication and data encryption.

To provide support for a transaction-based session application in which
one end of the connection controls the session and issues a transaction
request that the other end carries out, see the chapter "AppleTalk Transaction Protocol (ATP)."

To gain access to the underlying AppleTalk transport protocol that allows you send discrete packets of data across the network without imposing on your application the additional overhead required to set up and maintain a session, see the chapter "Datagram Delivery Protocol (DDP)." To use DDP, you must provide socket-listener code that you must write in assembly language.

To provide complete coverage of the AppleTalk protocols, this book includes in the chapters "AppleTalk Session Protocol (ASP)" and "AppleTalk Filing Protocol (AFP)" a discussion of two higher-level protocols that are not commonly used by application program developers: AppleTalk Session Protocol (ASP) and AppleTalk Filing Protocol (AFP). ASP allows you to establish an asymmetrical session between an ASP workstation application and an ASP server application. The primary use of ASP is to provide services for the AppleTalk Filing Protocol (AFP) that, in turn, provides all of the services necessary to access an AppleTalk AppleShare server. AFP allows a workstation on an AppleTalk network to access and manipulate files on an AFP file server, such as an AppleShare server. Because you can use the native file system to access an AFP server from a workstation, in most cases you should not need to use AFP directly.

To register your application with the LAP Manager so that you will be notified when an AppleTalk transition event occurs that can affect your application, and to define a transition event that your application causes
to occur that can affect other applications, see the chapter "Link-Access Protocol (LAP) Manager." This chapter also describes how to install a protocol handler as a client of the LAP Manager if your application processes 802.2 Type 1 packets.

To learn how to write data directly to an Ethernet, token ring, or Fiber Distributed Data Interface (FDDI) driver instead of using the AppleTalk protocol stack, see the chapter "Ethernet, Token Ring, and Fiber Distributed Data Interface." This chapter also describes how to read data directly from an Ethernet driver.

To implement a special-purpose application that receives and processes AppleTalk packets in a custom manner instead of passing them directly on to a higher-level AppleTalk protocol for processing, see the chapter "Multinode Architecture."

Because the AppleTalk network system includes both hardware and software--and because the software includes not only the AppleTalk protocol stack and the programming interfaces to it, but also file servers, print servers, internet routers, drivers for circuit card or network interface controllers, and so forth--the information in this book constitutes only a small part of the body of literature documenting AppleTalk.

For a detailed description of the AppleTalk protocol specifications, see Inside AppleTalk, second edition. For a complete description of the LAP Manager, EtherTalk, and other AppleTalk connections, see the Macintosh AppleTalk Connections Programmer's Guide. To learn how to install and operate an AppleTalk internet, see the AppleTalk Internet Router Administrator's Guide and the AppleTalk Phase 2 Introduction and Upgrade Guide. For an introduction to the hardware and software of an entire AppleTalk network, see Understanding Computer Networks and the AppleTalk Network System Overview. For informa-
tion on designing circuit cards and device drivers for Macintosh computers, see Designing Cards and Drivers for the Macintosh Family, second edition.

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Preface Contents

What to Read

Chapter Organization

Conventions Used in This Book

Special Fonts

Types of Notes

Assembly-Language Information

Numerical Formats

Development Environment

Developer Products and Support