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

6 FICON Administrator’s Guide

53-1002753-01

FICON configurations

Cascaded FICON

Cascaded FICON refers to an implementation of FICON that uses one or more FICON channel paths

whereby the domain ID of the entry switch is different than the domain of the switch where the

control unit is attached. Therefore, cascading requires a 2-byte link address. Any time a 2-byte link

address is defined on a channel, all link addresses must be 2-byte link addresses.

Switches may be interconnected using the following links:

• Traditional ISLs

• Inter-Chassis Links (ICL)

• Fibre Channel over Internet Protocol (FCIP)

The processor interface is connected to one switch (known as the entry switch), while the storage

interface is connected to the other. This configuration is supported for both disk and tape, with

multiple processors, disk subsystems, and tape subsystems sharing the ISLs or ICLs between the

switches and Backbones. Multiple ISLs between the switches and Backbones are also supported.

Cascading between switches and Backbones is also supported, An example of this would be a

Brocade DCX 8510-8 Backbone enterprise-class platform connected to a Brocade 6510.

A cascaded configuration (Figure 3) requires two-byte addressing. Two byte-addressing requires a

list of authorized switches. This authorization feature, called fabric binding, is available through the

Secure Access Control List feature. The fabric binding policy allows a predefined list of switches

(domains) to exist in the fabric and prevents other switches from joining the fabric. This type of

configuration is described in “User security considerations” on page 17.

FIGURE 3 Cascaded FICON

There are hardware and software requirements specific to two-byte addressing:

• The FICON switches themselves must be from the same vendor (that is, both should be from

Brocade).

Site A

FC Switch FC Switch

FC Link

FICON CU

Site B

ISL