IBM 990 FICON channel in Fibre Channel Protocol (FCP) mode

Chapter 3. I/O system structure 97

Draft Document for Review April 7, 2004 6:15 pm 6947ch03.fm

The z990 FICON Express SX feature (feature code 2320) occupies one I/O slot in the z990

I/O cage. The feature has two Peripheral Component Interconnect cards. Each PCI card has

a single port supporting an LC Duplex connector, with one PCHID associated with each port,

and supports link speeds of 1Gbps and 2 Gbps.

Each port supports attachment to the following:

򐂰Fibre Channel Switch that supports 1Gbps/2Gbps Fibre Channel/FICON SX

򐂰Control unit that supports 1Gbps/2Gbps Fibre Channel/FICON SX

Each port of the z990 FICON Express SX feature uses an 850 nanometer (nm) fiber

bandwidth transceiver. The port supports connection to a 62.5 micron or 50 micron multimode

fiber optic cable terminated with an LC Duplex connector.

FICON channel in Fibre Channel Protocol (FCP) mode

When configured for FCP mode, the FICON Express features can access FCP devices either:

򐂰Via a FICON channel in FCP mode through a single Fibre Channel switch or multiple

switches to an FCP device

򐂰Via a FICON channel in FCP mode through a single Fibre Channel switch or multiple

switches to a Fibre Channel-to-SCSI bridge

The z990 servers, Linux for zSeries, and z/VM work together to provide performance

improvements by exploiting extensions to the Queued Direct Input/Output (QDIO)

architecture. Adapter Interruptions, first added to z/Architecture with HiperSockets, provide an

efficient, high-performance technique for I/O interruptions to reduce path lengths and

overhead in both the host operating system and the adapter - FICON Express, when using

the FCP CHPID type.

In extending the use of adapter interruptions to FCP channels, the programming overhead to

process a traditional I/O interruption is reduced. This benefits FCP support in Linux for

zSeries.

Note: Mode Conditioning Patch (MCP) cables are for use with 1Gbit/sec (100 MB/sec)

links only.

Multimode (62.5 or 50 micron) fiber optic cable may be used with the z990 FICON Express

LX feature for 1 Gbps only. The use of this multimode cable type requires a Mode

Conditioning Patch (MCP) cable to be used at each end of the fiber optic link, or at each

optical port in the link. Use of the single-mode to multimode MCP cables reduces the

supported optical distance of the 1 Gbps link to an end-to-end maximum of 550 meters.

Fiber optic conversion kits and Mode Conditioning Patch (MCP) cables are not

orderable as features on z990. Fiber optic cables, cable planning, labeling, and

installation are all customer responsibilities for new z990 installations and upgrades.

IBM Fiber Cabling Services offer total a cable solution service to help with your cable

ordering needs, and is highly recommended.

Note: z990 FCP channel direct attachment in point-to-point and arbitrated loop topologies

is not supported as part of the zSeries FCP enablement.