3Com 155 PCI manual Emulated LAN ELAN Overview, LAN Emulation Client LEC found on all end stations

Emulated LAN (ELAN) Overview 1-3

Emulated LAN (ELAN) Overview

The 3Com ATMLink network driver conforms to the ATM Forum LAN Emulation over ATM Specification 1.0 to interoperate with legacy LAN networks. LAN emulation supports the multicast, broadcast, and address resolution services characteristic of shared media LANs, within the connection-oriented ATM environment. Four devices are defined to provide these LAN emulation services:

■LAN Emulation Client (LEC) found on all end stations

■LAN Emulation Configuration Server (LECS)

■LAN Emulation Server (LES)

■Broadcast and Unknown Server (BUS)

The 3C975 ATMLink NIC network driver provides the LAN Emulation Client and supports up to 16 LECs per NIC. Each LEC configured on an ATMLink NIC is regarded by the network operating system as a separate (emulated) NIC and receives a unique MAC address. An “emulated” NIC connects to an emulated LAN (ELAN). In short, each physical ATMLink NIC can connect to up to 16 separate ELANs.

The term ELAN is often used to denote an LEC in the 3Com ATMLink utilities, installation programs, and user guide.

An ELAN is a logical grouping of end stations within an ATM network. The ATM network administrator creates ELANs when configuring the ATM switches. Membership in an ELAN is independent of the physical location of the end station within the ATM network. An end station can belong to multiple ELANs simultaneously. Mixed-media edge devices (such as the 3Com LinkSwitch® 2700 switch) that are connected to ATM switches enable ATM end stations to interoperate with legacy LAN end stations, because the legacy LAN end station and the ATM end station can be members of the same ELAN. This guide includes configuration procedures that allow an LEC to join an ELAN.