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126 Chapter 4: ATM Solutions
LEC (LAN Emulation Client)
A LEC can be an ATM end station, a router, a switch, or a bridge. The LEC is responsible for
data forwarding, address resolution, control functions, and emulating MAC functions to upper-
layer protocols. The LEC registers its MAC and ATM addresses with the LES.
Routers can connect diverse LAN and WAN links to existing ATM internetworks. Routers can
perform vital ATM services such as multicast server, ARP server, and LAN emulation server. A
single Cisco router with compatible IOS features can serve as a LECS, a LES, a BUS, and a
LEC. Figure 4-6 depicts a LAN emulation circuit.
Figure 4-6
LAN Emulation Circuit
Figure 4-7 illustrates a high-speed workgroup and campus backbone application utilizing ATM
as a high-speed protocol.
Figure 4-7
ATM as a High-Speed Workgroup and Campus Backbone Application
LE server
Broadcast & unknown server
LE configuration server
LE client
LE client
LE-ARP
LE client
Complex
university
campus
87200333.book Page 126 Wednesday, August 22, 2001 2:18 PM