Users Guide

support.dell.com PowerVault 51F Commands 4-11
The switch provides the ability to tune the switch in a specific application, by configur-
ing the parameters for the switch's eight virtual channels. Note that the first two
virtual channels are reserved for the switch's internal functions and are not
user-configurable. The default virtual channel settings have already been 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 effects of those
changes. Table 4-6 describes the virtual channel parameters.
VC Encoded
Address
Mode
When this mode is set, frame source and destination addresses
utilize an address format compatible with PowerVault 50F
system.
When this mode is set to
0
, 239 PowerVault 51F switches may
be cascaded.
Disable Trans-
lative Mode
The setting is only relevant if VC Encoded Address Mode is also
set. When set, this mode maintains explicit address compatibility
with first-generation switches. However, enabling this feature
also disables translative/phantom addressing.
Set this mode only if hardware or software systems are attached
to the fabric which explicitly rely on a specific frame address
format.
Per-frame
Route Priority
In addition to the eight virtual channels used in frame routing pri-
ority, support is also available for per-frame based prioritization.
When set, the virtual channel ID will be used in conjunction with
a frame header to form the final virtual channel ID.
Table 4-6. Virtual Channel Parameters
Field Description Default
VC Link
Control
This changes the virtual channel used for N_Port-
generated, Class 2 link control frames (ACKs,
P_BSYs, and P_RJTs).
0 = Force N_Port-generated link control frames
to be sent back using a Class 2 data virtual
channel.
1 = Force N_Port-generated link control frames
to be sent back using a virtual channel normally
reserved for fabric-internal traffic.
0
VC Class 2 Sets the virtual channel used for Class 2 frame
traffic. May be set to virtual channel 2, 3, 4, or 5.
2
VC Class 3 Sets the virtual channel used for Class 3 frame
traffic. May be set to virtual channel 2, 3, 4, or 5.
3
Table 4-5. Fabric Parameters
(continued)
Field Description