EMC Symmetrix DMX-3, Руководство по эксплуатации продукта, Страница: 97 / 326

Channel attachments 97
Symmetrix DMX-3 Hardware
Mainframe serial
channel extenders This section describes the various types of conversion devices and
channel extenders compatible with Symmetrix systems for channel
attachment. Symmetrix systems can attach to ESCON (serial)
channels directly, or through ESCON channel extenders, or directors.
Note: Each repeater can be either an ESCON director or an IBM 9036 Remote
Channel Extender. If two ESCON directors are used, one of them must use
ports that are dedicated to the Symmetrix-to-ESCON channel path.
ESCON director The ESCON director provides dynamic switching and extended link
path lengths (with XDF capability) when attaching an ESCON
channel (TYPE=CNC) to a Symmetrix serial channel interface. One or
two ESCON directors may be configured in the channel attachment.
However, one of the directors must be configured with a static
connection because the ESCON architecture recognizes only one port
address. The dynamic switch configuration is defined in the IOCP.
The ESCON director may also be used to provide additional
flexibility and extend channel lengths when used with channel
converters.
Table 22
Symmetrix ESCON cable distances
Cable type Cable description Maximum distance
a
Direct fiber, multimode 50 micron 2 km (1.24 miles) per cable segment
62.5 micron 3 km (1.86 miles) per cable segment
Fiber repeaters/converters (for example,
McDATA 9191 to McDATA 9191)
3 converters/repeaters maximum allowed 9 micron 30 km (18.64 miles) per cable segment
Other fiber repeaters/converters
three converters/repeaters maximum allowed 9 micron 20 km (12.42 miles) per cable segment
b
a. A cable segment is a physical cable connecting one node to another.
b. Typical best-case distance specifications are quoted; refer to specific vendor’s equipment for current information.