FICON Administrator's Guide v6.4.0 (53-1001771-01, June 2010)

56 FICON Administrator’s Guide
53-1001771-01
Traffic Isolation Zoning
5
Emulation topology
FICON device emulation topologies have unique requirements due to the characteristics of the
emulation devices. Each device must track the emulated sessions and maintain the state of the
emulated devices in order to satisfy both ends of the connection. Since this is done over very long
distances, care must be taken when configuring the ISL connections to insure that the sessions
remain along exclusive paths. By maintaining an exclusive path between the emulation units, the
recovery scenarios become manageable and allow system level mechanisms to take precedence,
that is the device level recovery at the channel or control unit.
Generally, channel to control unit access is deployed as one-to-many topology; where, one channel
is defined to access many control units. FICON environments, however, are deployed in multiple
redundant configurations that also define access from one control unit to many channels. When
emulation is involved these configurations can result in overlapping channel and control unit
connections that make emulation isolation difficult. By using the Enhanced TI Zoning feature to
support device membership in multiple zones, these types of emulation configurations are
addressed.
FIGURE 19 Emulation topology using Enhanced TI Zones
CPU1
0
40 41
1B1A
1E 1E0F 1E
83
82
80
81
1
Grid 1
TI Zone 1
Grid 4
TI Zone 2