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Chapter 4
ATM Administration
Getting Started
Upgrading a legacy Ethernet network to an Ethernet network with ATM
backbone access provides higher throughput as well as the benefits of added
bandwidth. On the other hand, it also brings the problem of compatibility. For
example, legacy LAN networks and ATM networks have two differences that
must be resolved by any protocol which attempts to interface the two
technologies:
❑
LAN (MAC) address are defined by the IEEE 802.x specification (48
bits, preassigned at the time of manufacture). ATM addresses, on the
other hand, are larger and hierarchical, with ATM station addresses
derived from either the ATM switch itself or the ATM network at
large.
❑
Legacy LAN networks broadcast to all devices that are attached to
the network. ATM networks must set up connections to all member
stations before broadcasting data.
The resolution of these differences is to be found in LAN Emulation (LANE).
The bottom line is straightforward: LANE allows legacy LANs to
communicate across ATM switches.
LANE is implemented in either of two configurations:
1.
As an intermediate system such as a bridge or a router which enable
communication among legacy LANs over ATM backbone networks.
2.
As an End Station such as hosts, workstations, servers, or PCs which
enable communication between End Stations on a legacy LAN or among
ATM End Stations.
