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## 4.7.2 Storage connectivity 

a. UTP is unshielded twisted pair. Consider the use of category 6 UTP for 1000 Mbps connections. 

b. Or 50 µm MM OM3 (2 GHz-km), but OM4 is highly recommended. 

MM = Multi-Mode SM = Single-Mode 

Connectivity to external I/O subsystems (for example, disks) is provided by FICON channels and zHyperLink$^{4}$. 

## FICON channels 

z14 supports the following FICON features: 

GLYPH<SM590000> FICON Express16S+ 

GLYPH<SM590000> FICON Express16S 

GLYPH<SM590000> FICON Express8S (carry-forward only) 

The FICON Express16S+, FICON Express16S, and FICON Express8S features conform to the following architectures: 

GLYPH<SM590000> Fibre Connection (FICON) 

GLYPH<SM590000> High Performance FICON on Z (zHPF) 

GLYPH<SM590000> Fibre Channel Protocol (FCP) 

The FINCON features provide connectivity between any combination of servers, directors, switches, and devices (control units, disks, tapes, and printers) in a SAN. 

Each FICON Express16S+, FICON Express16S, and FICON Express 8S feature occupies one I/O slot in the PCIe I/O drawer. Each feature has two ports, each supporting an LC Duplex connector, with one PCHID and one CHPID associated with each port. 

All FICON Express16S+, FICON Express16S, and FICON Express8S features use SFP optics that allow for concurrent repairing or replacement for each SFP. The data flow on the unaffected channels on the same feature can continue. A problem with one FICON port no longer requires replacement of a complete feature. 

All FICON Express16S+, FICON Express16S, and FICON Express8S features also support cascading, which is the connection of two FICON Directors in succession. This configuration minimizes the number of cross-site connections and helps reduce implementation costs for disaster recovery applications, IBM Geographically Dispersed Parallel Sysplex™ (GDPS), and remote copy. 

IBM z14™ servers support 32K devices per FICON channel for all FICON features. 

Each FICON Express16S+, FICON Express16S, and FICON Express8S channel can be defined independently for connectivity to servers, switches, directors, disks, tapes, and printers, by using the following CHPID types: 

GLYPH<SM590000> CHPID type FC: The FICON, zHPF, and FCTC protocols are supported simultaneously. 

