Re: iSCSI : Reject PDU Concerns.

[julian_satran@il.ibm.com]

That is not completely accurate.  You could enter the marker intervals if
you know them or, assuming that you have CRCs the analyzer can look for
48byte sequence (or 56 byte sequences) with a correct CRC and after finding
several block that make sense consider itself synched. Consider also that
after any longer silence the ULP will be aligned with TCP.  The analyzer
could work as it can loose data!

Julo

Matt Wakeley <matt_wakeley@agilent.com> on 23/01/2001 20:54:54

Please respond to Matt Wakeley <matt_wakeley@agilent.com>

To:   IPS Reflector <ips@ece.cmu.edu>
cc:
Subject:  Re: iSCSI : Reject PDU Concerns.




julian_satran@il.ibm.com wrote:

> 2) An error_byte field should be considered for inclusion in the Reject
> PDU which contains the byte offset of the errant byte[or word] in the
> received header/payload that caused the target to send a Reject response
> to the command.
>
> This is a simple solution that provides for quick fault isolation and
> root cause of the reason for the reject. This also rids the Reject PDU
> of any detailed elaboration of reason codes meant to allow root cause of
> the reason for the reject.
>
> <js> that is no big help since there can be more than one error and it
> helps mostly in debugging. For implementation errors in the target and/or
> initiator I am sure the protocol analyzer will be happy to help but
running
> implementation should not be burdened with. For those that are running
> errors on good implementations we will provide some details when
necessary
> </js>

Julian,

With only in-band framing [the markers that are currently defined in the
spec], there is no way a protocol analyzer can be used in the traditional
way.  In order for the protocol analyzer to work, it would have to be
continuously running since the tcp connection(s) was  established.
Besides,
early on there will not be any protocol analyzers.

-Matt