Brocade FICON Administrator's Guide v7.1.0 (53-1002753-01, March 2013)

34 FICON Administrator’s Guide
53-1002753-01
Control Unit Port overview
3
FIGURE 10 FICON CUP
Figure 10 is a simplified representation of a FICON environment and how CUP fits into that
environment. FICON switches with FMS enabled use port address “FE” as the embedded internal
port for host connectivity to the CUP, and port address “FF” is reserved. Therefore, addresses “FE”
and “FF” cannot be used for assignment to physical ports when FMS is enabled. For more
information, refer to “Disabling ports 0xFE and 0xFF” on page 38.
In a FICON environment, only one RMF LPAR should be configured to poll the CUP for port statistical
counter data in order to minimize contention for the CUP device. Host contention for access to the
CUP can lead to missing interrupts, potentially causing the host to box the device. It is a best
practice however to have more than one CHPID defined as a path to the CUP in order to ensure
redundancy for host-to-CUP connectivity.
FICON CUP restrictions
The following restrictions apply to Brocade FICON switches having at least 256 ports when FMS
mode is enabled and when host applications are used for inband monitoring and management of
the switch:
• FICON Management Server mode (FMS mode) must be enabled on the switch to enable CUP
management features. When this mode is enabled, Fabric OS prevents configuration requests
from out-of-band management interfaces from interfering with host in-band configuration
requests by serializing access to switch parameters.
FE
FE
CHPIDs
Management
Application Server
FICON Switch
Embedded
port
FE
Embedded
port
Embedded
port
FICON director
FICON director
System Automation
OS390 application
I/0-CPs