Handbook of Local Area Networks, 1998 Edition:Advanced LAN Issues and Solutions Click Here! Search the site:   ITLibrary ITKnowledge EXPERT SEARCH Programming Languages Databases Security Web Services Network Services Middleware Components Operating Systems User Interfaces Groupware & Collaboration Content Management Productivity Applications Hardware Fun & Games EarthWeb sites Crossnodes Datamation Developer.com DICE EarthWeb.com EarthWeb Direct ERP Hub Gamelan GoCertify.com HTMLGoodies Intranet Journal IT Knowledge IT Library JavaGoodies JARS JavaScripts.com open source IT RoadCoders Y2K Info Previous Table of Contents Next Section 2Advanced LAN Issues and Solutions LAN technology does not stand still, and advances in LAN technology do not move in a straight line. Thus, to position the LAN for high performance and added value to the enterprise, the LAN manager needs to be cognizant of a number of trends. This section explores a number of issues and solutions at the leading edge, beginning with a technology that actually originated outside the LAN environment. Having their roots in the Internet, multicast applications allow for the definition and management of groups, and require that packets be delivered simultaneously to all members of a given group. Although LANs have traditionally had the inherent capability to perform multicasting, this emerging set of applications creates some challenges, especially since they are coming at a time when the trend is to rely more on switched LANs as opposed to shared media LANs. Chapter 2-1, “Multicast Network Infrastructures,” discusses this emerging set of applications, positioning LAN managers to better understand the issues involved. As indicated, one of the trends in LAN technology is to rely more on switched LANs. Chapter 2-2, “Multilayer IP/IPX Switching in the LAN,” describes multilayer switching as a solution for network designers and planners who are faced with the problem of upgrading their LANs to support growing traffic loads and changing patterns. Multilayer switching is described in this chapter as a complete, self-contained, and cost-effective alternative to more traditional LAN designs. A somewhat similar approach is discussed in Chapter 2-3, “Routing Hubs and ATM,” which focuses on networking and application technological trends likely to affect hub design in the coming years. Particular attention is paid to solutions that allow evolutionary, as opposed to revolutionary change. The topic of switching will be covered more in the next section. Shifting gears somewhat, Chapter 2-4, “Fibre Channel Architecture, Layers, and Services,” takes a look at a unique solution to the need to provide high-performance, low-cost connections in a local environment. This chapter describes the layered architecture of Fibre Channel, describes how the service interfaces with networking applications, and describes some implementation scenarios. Back into the more familiar realm of Ethernet, but at unfamiliar transmission speeds, Chapter 2-5 discusses the technology behind “Gigabit Ethernet,” the latest evolution of the 802.3 family of standards. The chapter discusses the application trends leading to the requirement for gigabit transmission capacity, describes in significant detail how the technology works, and assesses the technology's status with respect to the IEEE standardization process and industry support. While considering the ever-increasing transmission speeds and switching capacity, it is important to realize that LANs are advancing on other fronts as well. In particular, the remaining two chapters discuss how LAN technology is being extended into the areas of wireless networking and remote access. Chapter 2-6, “Wireless Networks,” discusses technologies available to implement LANs and other networks without the need for cabling. Such technologies are especially useful where wiring is impractical due, for example, to building design, right-of-way issues, or other environmental factors. An issue that remains an important challenge, both from a business and technology perspective, is the emergence of remote workers. Brought about primarily by the development of very powerful, yet truly portable computers, remote workers have begun to expect a level of service approaching that provided to stationary workers. Chapter 2-7, “Remote LAN Access Technology,” takes a look at the predominant technologies currently available to satisfy this business need. 2-1Multicast Networking C. KENNETH MILLER Multicast transmission is the sending of one message to many, but not all, receivers. Multicast network infrastructures are becoming available in all kinds of data networks, including wide area, satellite, and wireless. This new infrastructure is being used for group-oriented data networks. Broadcast transmission is the sending of one message to all receivers and has been used extensively in LAN environments. Broadcast traffic over wide area networks (WANs), however, should be avoided because it can flood the WAN with unwanted traffic, or broadcast storms. Multicast provides the mechanism for one-to-many transmission over WANs without creating broadcast storms. Multicast network infrastructures can be created at layer 2 (i.e., the link layer) or at layer 3 (i.e., the network layer). The primary layer 3 multicast transport technique is multicast Internet protocol (IP), which many router vendors support. Layer 3 multicast transport is independent of the underlying network architecture. Different physical and link layer architectures support multicast and broadcast services. For example, satellite data transmission is a broadcast architecture that easily supports multicast services. Other network infrastructures are multicast LANs, multicast frame relay, and multicast SMDS. Previous Table of Contents Next Use of this site is subject certain Terms & Conditions. Copyright (c) 1996-1999 EarthWeb, Inc.. All rights reserved. Reproduction in whole or in part in any form or medium without express written permission of EarthWeb is prohibited. Please read our privacy policy for details.