director 2/64 installation guide

director 2/64 installation guide 3–13
Using EWS to Configure the Director 2/64
Fabric Parameters
Configure the following parameters as required by your fabric.
BB_Credit
Configure the director to support buffer to buffer credit (BB_Credit) from 1 through
60. This is the value used for all ports, except those configured for extended distance
buffering (10-100 km). The default value is 16. For a description of the
buffer-to-buffer credit, refer to the industry specification, Fibre Channel Physical and
Signaling Interface.
R_A_TOV
Configure resource allocation time-out value (R_A_TOV) in tenth-of-a-second
increments. This variable works with the error detect time-out value (E_D_TOV)
variable to control the director’s behavior when an error condition occurs. Resources
are allocated to a circuit when errors are detected and are not released for reuse until
the time set by the R_A_TOV value expires. The default value is 100 tenths (10
seconds). Set a value between 10 tenths and 1200 tenths (1 through 120 seconds).
NOTE: Set the same value for R_A_TOV on all directors and edge switches in a multiswitch
fabric. If the value is not the same on all units, the fabric segments. Also, the value for R_A_TOV
must be greater than the value configured for E_D_TOV.
E_D_TOV
Adjust the E_D_TOV in tenth-of-a-second increments. An error condition occurs
when an expected response is not received within the time limit set by this value. The
default value is 20 tenths (2 seconds). Set a value between 2 tenths through 600 tenths
(.2 through 60 seconds).
NOTE: Set the same value for E_D_TOV on all switches and directors in a multiswitch fabric. If
the value is not the same, the fabric segments.
Switch Priority
Setting this value determines the principal director for the multiswitch fabric. Choose
Principal (highest priority), Default, or Never Principal (lowest priority) from the
Switch Priority drop-down list.
Setting these priority values determines the principal director selected for the
multiswitch fabric. For example, if you have three directors in the fabric and set one as
Principal, one as Default, and one as Never Principal, the unit set to Principal
becomes the principal director in the fabric.