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 ENABLING TECHNOLOGIES The diffusion of Gigabit Ethernet into the marketplace will be done in parallel with several enabling/facilitating technologies, much as Fast Ethernet diffused in parallel with switching. Some of these enabling technologies—dash full duplex operation, flow control, and full duplex repeaters—have already been discussed, as they operate via Ethernet standards. Other enabling technologies emerging from other standards groups include Layer 3 switching, classes of service, support for time-sensitive applications, and VLANs. Layer 3 switching extends the speed and power of switching technology to Layer 3 routing and is a natural outgrowth of the switching technology that appeared in the early 1990s. Until recently, most switches have operated at ISO Layer 2—making decisions based on MAC addresses. Layer 3 switches extend the speed of switching technology to Layer 3 addresses (usually based on IP protocol), allowing better network management and segregation of network traffic while eliminating the bottleneck of long router processing latency. Class of service technology provides the ability to assign priorities to messages to assure the delivery of time-sensitive information. Although priorities and time-sensitive delivery have been available with other networking solutions, such as Token Ring, FDDI, and ATM, Ethernet has traditionally remained a single priority system. Work currently underway in the IEEE 802.1 High Layer Working Group (project 802.1p) and in 802.3 (proposed project 802.3ac) will soon provide a standards-based approach to attach priorities to Ethernet frames. Transmission of voice, video, and multimedia content over networks brings its own set of problems. Solutions to these problems are coming from the Internet Engineering Task Force (IETF) via technologies such as IP Multicasting, RSVP, and RTSP. IP Multicasting is an extension to the standard IP network level protocol (RFC 1112) to facilitate the one-to-many delivery of time-sensitive information to a group of users by broadcasting datagrams to a host group identified by a single IP destination address. RSVP, the ReSerVation Protocol, provides a way of creating multi-hop connections across routers with a specified quality of service level to support specific data streams or traffic flows. RTSP, the Real Time Streaming Protocol, is an application-layer protocol for controlling the on-demand delivery of time-sensitive data such as audio and video. These protocols require intermediate device (router, switch) support. VLANs (virtual LANs) are a management tool for organizing users into logical groups rather than physical ones. Since the organization is logical, individual users can be swiftly transferred from one VLAN to another via management tools. Many manufacturers already offer proprietary VLAN implementations for switches. The standard for VLAN operation, IEEE 802.1Q, is currently in development. SUMMARY Gigabit Ethernet is an extension of the IEEE802.3 Ethernet family of local area networking technologies. It is designed to integrate smoothly with legacy Ethernet systems, just like 100BASE-T. Gigabit Ethernet offers an easy-to-use, scalable technology to expand and update legacy Ethernet Networks. Gigabit Ethernet uses the traditional Ethernet format and size and supports half-duplex (CSMA/CD) full-duplex operation. Gigabit Ethernet management uses the same management definition and MIBs, which means that most management tools should be able to work with Gigabit Ethernet products. Gigabit Ethernet supports operation over most LAN links including 50 and 62.5 micron multi-mode fiber, 10 micron, single-mode fiber, short runs of and standard EIA/TIA-568-A Category 5 copper links. This means it will work with most existing fiber and copper installations. The proposed standard (802.3z) is currently in the ballot process; approval is expected in the first half of 1998. Gigabit Ethernet is supported by a large number of vendors. Conformance and interoperability test mechanisms for Gigabit Ethernet are already in place and tests are being developed in parallel with the standards process. The Ethernet family of local area networking standards is developed under the IEEE 802.3 working group. The standard consists of a base volume and supplements. Fast Ethernet is currently described in a 1995 supplement containing Clauses 21-30. An additional supplement should be published in late 1997 containing Clause 31 (Full Duplex and Flow Control and Clause 32—1000BASE-T2) and a supplement covering Gigabit Ethernet (with the exception of 1000BASE-T) should be published in late 1998. (See Exhibit 2-5-5.) Exhibit 2-5-5.  Ethernet Standards Status and Coverage as of Summer 1997 Exhibit 2-5-5.  (Continued) Previous Table of Contents Next Use of this site is subject certain Terms & Conditions. Copyright (c) 1996-1999 EarthWeb, Inc.. All rights reserved. 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