Brocade Communications Systems A7533A - Brocade 4Gb SAN Switch Base Command Reference Manual page 134

2
configure
The R_A_TOV, E_D_TOV, WAN_TOV, and MAX_HOPS configuration parameters are inter-related.
Data Field Size
Sequence-Level Switching
Disable Device Probing
Suppress Class F Traffic
Switch PID Format
0
1
2
Per-frame Route Priority
Long Distance Fabric
102
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:
Native PID Format (16 based, 16 port format), for fabrics with legacy
low-count port switches.
Core PID Format (0 based, 256 port format), preferred mode for mixed fabrics
with legacy and new switches.
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 level; otherwise, the fabric will be segmented.
Fabric OS Command Reference Manual
53-1000436-01