HP 1606 FICON Administrator's Guide v6.4.0 (53-1001771-01, June 2010) - Page 68

5 Traffic Isolation Zoning 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. CPU1 0 1 40 81 80 41 82 83 1A 1B 0F 1E 1E 1E TI Zone 1 Grid 1 Grid 4 TI Zone 2 FIGURE 19 Emulation topology using Enhanced TI Zones 56 FICON Administrator's Guide 53-1001771-01