Brocade FICON Administrator’s Guide (Supporting Fabric OS v7.3.0) - Manual (Page 71)

pipeline and requests more data from the tape. If an exception status is received from the device, the
reading of data and emulation is terminated.
FIGURE 19 Tape Read Pipelining
FICON and ESCON conversion support
Brocade extension switches and blades can operate with the Prizm FICON to ESCON converter and
ESBT Bus/Tag Interface Module for Prizm from Optica Technologies, Inc. This allows FICON tape
emulation when connecting to ESCON and to bus and tag devices including 3480, 3490, and 3590
controllers. Discovery of these devices is automatic when FICON emulation is enabled on an FCIP
tunnel.
Printer emulation
Brocade extension switches and blades can operate with a Prizm FICON to ESCON converter and an
ESBT Bus/Tag Interface Module for Prizm from Optica Technologies, Inc. This allows FICON printer
emulation when connecting to printers such as the 1043, 3203, 3211, 3800, 4245, 4248, 6262, Xeros
Printer Access Facility (XPAF), and Intelligent Printer Data Stream (IPDS) models. Discovery of these
devices is automatic when FICON emulation is enabled on an FCIP tunnel.
For printer emulation, basic write streams are emulated to help resolve link latency resulting from
channel programming and associated FICON protocols. Because most supported printers will be
connected through the Prizm FICON to ESCON converter or ESBT Bus/Tag Interface Module, resolving
latency on the WAN is not required. The bottleneck will be the remote channel connection where it is
more important to have outstanding commands queued. Basic read commands known to be part of the
write command chain, typically those that read printer page counters, will be handled locally without
waiting for the actual read data from the device.
This emulation provides the following benefits:
FICON and ESCON conversion support
FICON Administrator's Guide 69
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