RE: new iSCSI PDU outline

["Douglas Otis" <dotis@sanlight.net>]

Julian,

Would you consider splitting headers.  As was done with MTF, there was just
a simple 32 bit simple XOR checksum for header fields.  Here is an example
with a CDB appended.  The WN could expand the appended type into SCSI_CMND,
SCSI_RSP, SCSI_R2T, iSCSI_Specific, etc.

  |7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|7 6 5 4 3 2 1 0|
  +---------------+---------------+---------------+---------------+
 0| WN            | Reserved                      | AddCDB        |
  +---------------+---------------+---------------+---------------+
 4| Length                                                        |
  +---------------+---------------+---------------+---------------+
 8| ->CmdSN or <-StatRN                                           |
  +---------------+---------------+---------------+---------------+
12| ->ExpStatSN or <-ExpCmdSN                                     |
  +---------------+---------------+---------------+---------------+
16| ->MaxStatRN? <-MaxCmdSN                                       |
  +---------------+---------------+---------------+---------------+
20| XOR Checksum                                                  |
  +---------------+---------------+---------------+---------------+
  +---------------+---------------+---------------+---------------+
24| SCSI_CMND  ...                                                |
  +-                                                              |
32|                                                               |
  +---------------+---------------+---------------+---------------+
36| CDB ...                                                          |
  +---------------+---------------+---------------+---------------+
x | (Data ...)                                                         |
  +---------------+---------------+---------------+---------------+
y | CRC                                                           |
  +---------------+---------------+---------------+---------------+

Doug