This book looks at enterprise networking from the perspective of network users and application developers, describing the application services the network provides and the technologies employed to implement end-to-end communication between users. KEY TOPICS: Covers networking technologies such as TCP/IP, Novell Netware, NetBIOS, AppleTalk, SNA, and DECnet. MARKET: For information systems managers, communications managers, technical staff members who support networking hardware and software, and users of network services.
In the past, mainframes and minicomputers, with their attached terminals, formed the basis of most forms of corporate network computing. Since the early 1980s, individual workgroups in organizations have begun to use local area networks (LANs) as a way of sharing resources. Workgroup LANs administered by individual departments often coexist with the corporate networks administered by the central information systems organization. In many cases, individual departmental LANs have been interconnected to form extended networks that reach throughout the organization. These interconnected departmental networks often have the same scope as the corporate networks.
The traditional large information systems vendors, such as IBM and Digital, have been changing their networking products to better serve the needs of individual desktop users. At the same time, the vendors in the workgroup computing arena, such as Microsoft and Novell, have been expanding their products to better serve the needs of enterprise-wide computing. The term enterprise networking refers to a form of integrated networking that attempts to integrate the large wide area networks that have been constructed by information systems organizations with the local area networks that have been created by users in individual workgroups.
The goal of enterprise networking is to enable enterprise computing, where users throughout an organization are able to communicate with each other and to access data, processing services, applications, and other resources without regard to where they are located. The challenge for enterprise networking is to provide the organization with networking facilities that meet the needs of enterprise computing at reasonable cost. Compatibility is a key issue in providing connectivity between all users and resources on the enterprise network while keeping costs reasonable in the enterprise computing environment.
To facilitate compatibility, standards organizations and hardware and software vendors have cooperated to develop architectures for enterprise networking that allow products from different vendors to interoperate. A number of important architectures and technologies used in enterprise networking are described in this book.
The subject of enterprise networking can be approached in a number of different ways. A high-level perspective takes the view of network users and application developers. With this perspective, it is important to describe the application services the network provides and the technologies employed to implement end-to-end communication between users. This book looks at enterprise networks from this high-level perspective.
Another important aspect of enterprise networking-especially to those who implement the network-concerns the technologies used for moving data over the individual physical connections that make up the network. A companion book to this one, Enterprise Networking: Data Link Subnetworks, concentrates on the lower-level subnetwork technologies. A third book, Local Area Networks: Architectures and Implementations, looks at data link technology for local area networks in even more detail.
Plan of the Book
The chapters of this book are divided into five parts. Part I introduces the enterprise networking environment. The chapters in Part I describe the characteristics of enterprise networks, introduce the various network architectures on which enterprise networking hardware and software products are based, and present an architectural model for enterprise networks.
Part II discusses the various types of services that enterprise networks provide for end users and for application programs. The chapters in Part II discuss general application services, naming and directory services, network management services, and the services provided by the Open Software Foundation Distributed Computing Environment (OSF DCE)
Part III describes the enterprise networking technologies used to transport user data, on an end-to-end basis, from a source machine to a destination machine. The chapters in Part III introduce the characteristics of the transport network, describe the various types of data transport facilities used in enterprise networks-including TCP/IP, Novell NetWare, NetBIOS, AppleTalk, SNA, and DECnet-and examine application programming interfaces provided by Transport network technology.
Part IV introduces the characteristics of data link subnetwork technologies used to build enterprise networks. The chapters in Part IV introduce the types of services provided by an individual data link in an enterprise network and describe network driver software used to interface with subnetworks.
Part V examines the technologies used for interconnecting user machines and data links to form integrated enterprise networks. The chapters in Part V introduce strategies for network interconnection, describe specific technologies for implementing interconnections-including repeaters, hubs, bridges, routers, gateways, and encapsulation facilities-and examine strategies useful for implementing networks that handle multiple transport protocol families.
This book is intended for a broad range of readers, including the following:
Information systems and communications managers and technical staff members who maintain and administer computer networks and who need a thorough understanding of networking technology.
Information systems and communications technical staff members who select, install, and support network hardware and software products and who deal with the complexities of multi-vendor networking.
Users of network services who desire an understanding of the technology behind the computer communication tools used in their work environment.
Students who are studying computer communications technologies.
Kathleen Kavanagh Chapman