Brocade Communications Systems A7990A - StorageWorks SAN Director 4/16 Blade Switch Command Reference Manual page 132

Note: Enter commands in lowercase only; mixed case is for readability.
2
configure
Data Field Size
Sequence-Level Switching
Disable Device Probing
Suppress Class F Traffic
Switch PID Format
Per-frame Route Priority
Long Distance Fabric
2-98
Note
The R_A_TOV, E_D_TOV, WAN_TOV, and MAX_HOPS configuration
parameters are inter-related. Assigning a specific value to one or more of these
parameters can change the range of allowed values that can be assigned to the
other parameters. As a result, the user might not be able to set all the values within
the range displayed against each parameter. To reduce problems, the
configuration utility validates the modified parameter values and prompts the user
to re-enter some values, if the validation check fails.
The data field size specifies the largest possible value, in bytes, for the size of a
type 1(data) frame. The switch advertises this value to other switches in the fabric
during construction of the fabric as well as to other devices when they connect to
the fabric. Setting this to a value smaller than 2112 might result in decreased
performance.
When sequence-level switching is set to 1, frames of the same sequence from a
particular source are transmitted as a group. When this feature is set to 0, frames
are transmitted interleaved among multiple sequences.
Under normal conditions, sequence-level switching should be disabled for better
performance. However, some host adapters have performance issues when
receiving interleaved frames from multiple sequences. When there are such
devices attached to the fabric, sequence-level switching should be enabled.
When disable device probing is set to 1, devices that do not register with the Name
Server will not be present in the Name Server data base. Set this mode only if the
switch's N_Port discovery process (PLOGI, PRLI, INQUIRY) causes an attached
device to fail.
By default, the switch can send Class F frames. When this option is turned on,
Class F traffic is converted to Class 2 traffic before being transmitted.
The formats are as follows:
0 Native PID Format (16 based, 16 port format), for fabrics with legacy
low-count port switches.
1 Core PID Format (0 based, 256 port format), preferred mode for mixed
fabrics with legacy and new switches.
2 Extended Edge PID Format (16 based, 256 port format), used in mixed
fabrics with legacy and new switches to avoid the need to reboot host
systems when static PID binded is used.
In addition to the eight virtual channels used in frame routing priority, support is
also available for per-frame-based prioritization when this value is set. When Per-
frame Route Priority is set to 1, the virtual channel ID is used in conjunction with
a frame header to form the final virtual channel ID.
When this mode is set to 1, ISLs in a fabric can be up to 100 km long. The exact
distance level is determined by the per-port configuration on the E_Ports of each
ISL. Both E_Ports in an ISL must be configured to run the same long-distance
Fabric OS Command Reference Manual
Publication Number: 53-1000240-01