RE: draft URL

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

Julian,

As David Black pointed out, the word "impossible" may be a bit strong for
finding PDUs with respect to snooping test equipment.  In the next
paragraph, the result of setting the urgent bit is not correctly stated by
indicating the urgent pointer will be pointing to the first byte of an iSCSI
message in the TCP segment.  This should be reworded to state:

   The result provides an Urgent Pointer pointing to the first or
   second byte of a PDU.  If the PDU is within the TCP segment,
   then this PDU will be the last PDU contained.

No assurance must be made as to whether the Urgent Pointer will be contained
within the TCP segment.  The statement 'first byte of a iSCSI message' is
also misleading in that an assumption is often made that the pointer will be
positioned to the first message rather than the last.  This should be
clearly stated.  I still hope for an API that illustrates a mechanism for
allowing this technique to be beneficial.

Page 13,

   "Unfortunately, when relying solely on the "message length in the
   iSCSI message" scheme to delineate iSCSI messages, a missing TCP
   segment that contains an iSCSI message header (with the message
   length) makes it impossible to find message boundaries in subsequent
   TCP segments. The missing TCP segment must be received before any
   following segments can be processed.

   The iSCSI protocol uses the urgent bit in the TCP header to delineate
   iSCSI messages. The first byte, and only the first byte, of every
   iSCSI PDU SHOULD be marked "urgent" if the receiving party has
   indicated its readiness to accept PDUs marked with the Urgent Bit &
   Pointer.  The result is that there will be a TCP segment with a valid
   TCP pointer (urgent flag set) pointing to the first byte of an iSCSI
   message in the TCP segment."

Doug

>
> Until the draft appears on the I-D repository you can pick it up from:
>
> http://www.haifa.il.ibm.com/satran/draft-ietf-ips-iSCSI-01.txt
>
> Please ignore the 00.txt that stil appears on the title page (I
> just forgot
> to change it).
>
> the older version is at:
>
> http://www.haifa.il.ibm.com/satran/draft-ietf-ips-iSCSI-00.txt
>
> Julo
>
>
>