HP Mainframe Connectivity Design Guide

FICON third-party director support
The following combinations of FICON directors in the same fabric are allowed; however, HP does
not provide support for third-party FICON directors. HP provides support for its products and
cooperates with the third-party's technical support staff, as needed.
• B-series with Brocade Silkworm
• C-series with Cisco MDS
• B-series with Brocade Mi10K, M6140, and M4700, as described in “Interoperability with
McDATA directors” (page 44)
NOTE: All FICON directors in a fabric must use the same firmware version.
Consider the following additional information for third-party director support:
• All FICON directors in a fabric must be from the same vendor (Brocade, Cisco, or McDATA),
including intermix environments.
• In general, you cannot use Brocade Silkworm and Brocade/McDATA Intrepid directors in the
same FICON fabric. For exceptions, see “Interoperability with McDATA directors” (page 44).
• You cannot use McDATA directors in the same FICON fabric with the discontinued
CNT/InRange FICON directors (UMD and FC/9000).
FICON SAN performance considerations
The following components affect FICON SAN performance:
• Mainframe model and capacity
• Channel (CHPID) speed
• Number of channels (CHPIDs)
• FICON SAN topology and number of fabrics
• Number of channel paths to the storage system
• Number of ports on the storage system
• Storage port speed
• I/O transfer sizes and usage patterns
• RAID controllers
• Disk configuration
Infrastructure factors
A single-switch fabric provides the highest level of performance. In a cascaded fabric, the following
factors can affect performance:
• Latency
Director latency is less than 5% (at 1 Gb/s) of the data transfer time, and therefore, is not a
major performance factor. However, in a cascaded fabric, as more devices send frames
through the same ISL, oversubscription can occur.
Distance latency also affects performance and is more difficult to overcome than
oversubscription. For more information, see “FICON and FICON SAN extension” (page 120).
• Oversubscription
Oversubscription degrades FICON SAN performance. When devices must contend for the
same ISL or path, each device receives an equal share or 1/n of the available bandwidth on
the path (where n is the number of contending devices). Oversubscription occurs when devices
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