Seagate Fibre Channel Interface User Manual
Page 75
Fibre Channel Interface Manual, Rev. D
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Common Features
This is a bit significant field which requests options that are used in all classes of service by initiator login. Below is a list of
the features and the drive requirements. The drive returns an LS_RJT to PLOGI requests that do not satisfy the require-
ments.
E_D_TOV (Pt to Pt) (Error Detect Time Out Value)
This field is only for point-to-point connections and is not valid for loop operation.
Highest ANSI FC-PH Version and Lowest ANSI FC-PH Version
The highest and lowest version of the ANSI Fibre Channel Physical and Signaling standards supported by the drive.
A version level of 09h is defined for FC-PH, Rev. 4.3. A version level of 20h is defined for FC-PH-3, Rev. 9.4.
Earlier drives supported by this manual require 09h in the highest and lowest version fields. An LS_RJT will be returned in
response to any PLOGI that does not satisfy this requirement. Later drives do not check the version fields in PLOGI and
return 20h in the PLOGI ACC. The version fields are not considered an accurate indicator of functionality. Reference the
drive product manual for specific behavior.
Receive Data Field Size
In the common and class 3 service parameters. Current drives check this field for the range 256 < fs < 2112 and a multiple
of four bytes. For multiple frame sequences, all frames but the last frame of the sequence must be this size. The drive uses
the receive buffer field size in the class 3 parameters when it sends frames. The drive returns the receive buffer field size in
the class 3 parameters from the initiator in the PLOGI ACC.
Relative Offset by Info Category
Indicates on a bit position basis which categories (e.g., solicited control, data descriptor) support the relative offset in the
FC header. The drive does not require relative offset and does not check this field in the PLOGI. The drive sends Relative
Offset in FCP Data frames (it sets 02h, bit 1 set, in the accept to indicate Relative Offset is supported for solicited data, cat-
egory 0001b).
Total Concurrent Sequences
Number of concurrent sequences across all classes of service. Sequences are concurrent if they are open and delivery
verification has not been received. It is the initiator’s responsibility to not issue commands to the drive that will exceed the
initiator’s capabilities for concurrent sequences.
The drive returns FFh in Concurrent Sequences field of the PLOGI ACC payload.
Table 25:
Common Features bits
Feature
Drive requirement
Continuously Increasing Offset
Must be a one (1).
Random Relative Offset
Not checked. Port Login Accept returns a value of zero (0). Not supported.
Valid Vendor Version
X
F_Port (Fabric Port)
Must be a zero (0) to denote a N_Port.
Alternate Credit Model
Must be a one (1).
E_D_TOV Resolution
Not checked. Port Login ACC returns 0.
Dynamic Half Duplex
Not checked. Port Login ACC returns 0.
Continuous Increase
SEQ_CNT
Not checked. Port Login ACC returns 0.
Payload Length
Not checked. Port Login ACC returns 0.