Departmental Switch Model DS-16B Hardware Reference Manual
Switch Management
Operating Mode The operating modes are determined by the host adapter. The six
operating modes for the switch are:
The administrator determines the adapter in use, then sets the switch
for the corresponding operating mode.
Virtual Channels The switch provides the ability to tune the switch in a specific
application.
The first two virtual channels are reserved for the switch’s internal
functions and are not available.
The default virtual channel settings are already optimized for switch
performance. Changing the default values, if properly selected, may improve
switch performance somewhat, but may also severely degrade performance.
You should not change these settings without fully understanding the
change’s effects.
Table 3-5 Operating Mode Definitions
Mode Description
Non-SCSI Tachyon Mode When set, multiple sequences from different sources are interleaved to
Tachyon-based controllers at Sequence boundaries rather than at
frame boundaries, resulting in better performance from Tachyon-based
controllers.
Isolated Operation Setting this mode isolates the switch from the rest of the Fabric.
Disable Device Probing When this is set, devices that do not register themselves with the Name
Server will not be present in the Name Server data base.
VC-Encoded Address Mode When this mode is set, frame source and destination addresses utilize
an address format compatible with some first-generation switches.
Disable Translative Mode The setting is only relevant if VC Encoded Address Mode is also set.
When set, this maintains explicit address compatibility with some first-
generation switches.
Per-Frame Route Priority In addition to the eight virtual channels used in frame routing priority,
support is also available for per-frame based prioritization when this
value it set. When set, the virtual channel ID will be used in conjunction
with a frame header to form the final virtual channel ID.
