RE: iSCSI: padding on intermediate sequences

[Sukha Ghosh <sukha_ghosh@ivivity.com>]

Just to clarify,

What Eddy (please correct me if I am wrong) is asking is that if a Data-in
response is multiple sequences of Data-In PDUs then the ending Data in PDUs
(F = 1)of intermediate sequences must also follow the 4-byte alignment rule
with pure data payload no padding. This means that only the last data-in PDU
can have padding, if necessary.   

-----Original Message-----
From: Robert D. Russell [mailto:rdr@io.iol.unh.edu]
Sent: Tuesday, March 26, 2002 2:48 PM
To: Eddy Quicksall
Cc: ips@ece. cmu. edu (E-mail)
Subject: Re: iSCSI: padding on intermediate sequences


Eddy:

I may not be understanding you correctly, but the
words in section 9.7.7 I believe mean that these data
segments should contain an integer number of 4 byte words
of data, not arbitrary "pad" bytes.  If the data segment
length is a multiple of 4 then there will be NO pad bytes.

There seems to be confusion over your use of "pad"
and the standard's use of "pad".  Would you please clarify?

Thanks,
Bob


On Tue, 26 Mar 2002, Eddy Quicksall wrote:

> Section 9.7.7 says:
>
> The Data Segments of Data-in and Data-out PDUs SHOULD be filled to the
> integer number of 4 byte words (real payload) unless the F bit is set
> to 1.
>
> This allows one to pad intermediate sequences of a transfer. But, there
are
> reasons why padding on intermediate sequences within a transfer can make
> life difficult.
>
> Can we forbid padding on all but the last PDU for the transfer? If that is
> objectionable, could we forbid padding on all but the last PDU of a
transfer
> if DataInOrder=yes.
>
> Eddy
>