HP Mainframe Connectivity Design Guide

FICON SAN components
A FICON SAN consists of the following hardware and software components:
• Directors
A FICON director creates the SAN fabric. By interconnecting directors, you can create scalable
SANs with thousands of port connections.
• Mainframes and channels
Channel cards provide an intelligent interface to the directors and CUs. Channel cards offload
all I/O function from the CPC, minimizing application processor overhead. Channel cards
contain multiple ports and are assigned CHPIDs.
• Storage devices
A SAN can integrate multiple storage system types, such as DASDs, disk arrays, and tape
libraries, to allocate storage efficiently.
• Cabling and cable connectors
Fiber optic cables provide the physical connections between SAN components.
• SAN management applications
HP applications manage and monitor components and ensure optimal SAN operation.
• CWDMs and DWDMs
You can use a CWDM or DWDM to extend the FICON SAN over long distances using dark
fiber (dedicated fiber link) between sites.
• Routers, bridges, and gateways
You can use FC-to-IP, FC-to-ATM or FC-to-SONET protocol conversion products to extend the
FICON SAN over long distances. The protocol conversion product must be certified to support
FICON. This requires an IP, ATM, SONET, or SDH circuit type.
FICON technology
FICON is a layer 4 protocol that runs over Fibre Channel and uses the FC-SB-2, FC-SB-3, FC-SB-4,
or the FC-SB-5 standard. Layers 1 through 3 are common to FCP and FICON, which enables them
to coexist (intermix) in a fabric.
NOTE: The main difference between FC-SB-2 and FC-SB-3 is that FC-SB-2 supports single-switch
fabrics only, and FC-SB-3 includes cascaded FICON director support.
The FC-SB-4 standard adds high-performance FICON features, including a new Transport Mode.
The FC-SB-5 standard expands on some of the high-performance capabilities introduced in the
FC-SB-4 standard. All currently offered HP FICON directors support Transport Mode and FC-SB-2
through FC-SB-5.
FICON was developed to convert ESCON channel programs to Fibre Channel frames to take
advantage of the speed, distance capabilities, capacity, and flexibility of Fibre Channel.
Table 1 (page 10) identifies the Fibre Channel protocol layers.
Table 1 Fibre Channel protocol layers
CCWsSCSI commandsProtocol
FICONFCPFC-4 layer
Common servicesFC-3 layer
Framing protocolFC-2 layer
10 FICON SAN design overview