3Com 7600 manual Virtual Lans, ATM Overview

12	ATM, LAN EMULATION, AND
	VIRTUAL LANS

	This chapter provides basic concepts and information about:
	Q	ATM Overview
	Q	Virtual Channels
	Q Interim Local Management Interface (ILMI)
	Q	LAN Emulation Overview
	Q	Emulated LAN Components
	Q	Emulated LAN Connections
	Q Bridges in the 7600 Card
	Q Data Transmission over an Emulated LAN
	Q	LEC Parameters
	Q	Virtual LANs Overview
	Q Virtual LANs in the 7600 Card
ATM Overview	The Asynchronous Transfer Mode (ATM) is a telecommunications method
	for carriage of a complete range of user traffic, including voice, video and
	data. Defined by CCITT and ANSI standards, it facilitates multi-media
	networking between high-speed devices at multi-megabit speeds.

Using this connection-oriented, switched networking technology, virtual channels may be set up to support multiple applications through the same physical connection. The switching technology enables dedicated bandwidth for each application, overcoming the restrictions that exist in a shared-media networking technology, like Ethernet, Token Ring and FDDI. ATM allows different types of physical layer technology to share the same lower layer – the ATM layer.