System information

Chapter 4. ATM LAN backbone interoperability and migration 69
there is little traffic between the Ethernet and token-ring ELANs. This traffic is
easily bridged or routed by the MSS.
Token-ring was chosen and may continue to be the LAN technology of choice
for workstation attachment. However, the market has chosen Ethernet, and
technological developments have compensated for most of the earlier
shortcomings of Ethernet. Economy and wider choices with Ethernet motivate
this organization to start a migration to Ethernet. So the first step in a
migration should be to enable an overlay Gigabit Ethernet backbone.
4.1.2 The migration phase
As all who have gone through a major technology migration have
experienced, it requires meticulous planning. However, clever use of available
technologies can provide a great deal of flexibility to the migration process to
ease some of the restraints that would otherwise have to be put on the
network and its users.
Figure 45 on page 70 shows a workable solution for migrating via an overlay
Ethernet backbone.