Subject: RE: iscsi: unsolicited data question

From: Arul Ponnusamy <[email-masked]>
Date: Thu, 13 Jun 2002 23:15:25 -0700

1) I have the same doubt as Deva. i.e Solicited mode and unsolicited mode
differ only with respect to the first outgoing data burst. 
Unsolicited mode:
R2T is not needed only for the first outgoing data burst. The subsequent
data MUST be solicited.
Solicited mode:
all data outs (including the first data out) MUST be solicited. 
 
Is this correct?
 
2) As per section 9.8 and 11.10, for WRITE operations without explicit
Initial R2T, the InitialR2T MUST have negotiated to NO. But as per 11.12
says that if InitialR2T=yes and ImmediateData=yes, then Immediate
unsolicited data only allowed. 
It looks like ambigous. Or Do I miss any other part of the spec which
explains this?

Arul

-----Original Message-----
From: Ranganathan, Deva [mailto:[email-masked]]
Sent: Thursday, June 13, 2002 6:59 PM
To: 'Julian Satran'
Cc: [email-masked]
Subject: RE: iscsi: unsolicited data question

"tells me that a target, at all times during a data sequence transfer, can
be

one or the other, but not both (non R2T for the initial data out, R2T for
the
remaining data).  Is this correct?"
 
really? I thought thatit is permissible to have non-R2T for the initial data
out and R2T for
remaining. i.e for a 64K transfer, the first 32K can be the first burst size
of data and
the next 32K will be solicited by the target through R2T. Am I missing
something?

-Deva

-----Original Message-----
From: Julian Satran [mailto:[email-masked]]
Sent: Wednesday, June 12, 2002 6:05 AM
To: Dennis Young
Cc: [email-masked]; [email-masked]
Subject: Re: iscsi: unsolicited data question

yes - julo 

	Dennis Young <[email-masked]> 
Sent by: [email-masked] 

06/12/2002 06:20 AM 
Please respond to Dennis Young 

        To:        [email-masked] 
        cc:         
        Subject:        iscsi: unsolicited data question 

I have a question which has been asked before, but I couldn't find a direct 
answer in the archive.  The table on page 200 of draft 12 doesn't directly
answer this question either.

The first paragraph on page 36 of draft 12 says "Targets operate in either 
solicitied (R2T) data mode or unsolicited (non R2T) data mode."
tells me that a target, at all times during a data sequence transfer, can be

one or the other, but not both (non R2T for the initial data out, R2T for
the
remaining data).  Is this correct?

Thanks,
Dennis

---snip from an old email dated 3/30/2001---

" Hi Julian 
Sorry if I'm covering old ground... Is it possible to use unsolicited data
for the first burst and then request any remaining data using R2T? For
example, if the target has a previously allocated buffer available (length
defined by FirstBurstSize) for unsolicited data, then once the initiator has
sent unsolicited data up to and including this amount then the remaining
data (if any) can be requested using R2T once the target has the buffer
space available. 
...Matthew Burbridge Hewlett Packard, Bristol Telnet: 312 7010 E-mail:
[email-masked] "

---

From: "Karthik Selvan" <[email-masked]>
Date: Fri, 14 Jun 2002 00:45:42 -0700

Hi,
        1) I have the same doubt as Deva. i.e Solicited mode and
unsolicited mode differ only with respect to the first outgoing data
burst. 

Unsolicited mode:
 
Is this correct? 
 
<karthik>Yes 
 
2) As per section 9.8 and 11.10, for WRITE operations without explicit
Initial R2T, the InitialR2T MUST have negotiated to NO.  
 
  <karthik> yes
 
 But as per 11.12 says that if InitialR2T=yes and ImmediateData=yes,
then Immediate unsolicited data only allowed.  
 
<karthik> Draft Section 11.2 clearly says that 
"If ImmediateData is set to Yes and InitialR2t is to Yes(default), then
only immediate data are accepted in the first burst."
 
 So it is not  ambigous.  (The word "immediate data" makes the
difference) 
Please refer previous postings in the mailing list. You can get detailed
answers.
 
Hope this helps
karthik selvan

-----Original Message-----
From: Ranganathan, Deva [mailto:[email-masked]]
Sent: Thursday, June 13, 2002 6:59 PM
To: 'Julian Satran'
Cc: [email-masked]
Subject: RE: iscsi: unsolicited data question

"tells me that a target, at all times during a data sequence transfer,
can be

one or the other, but not both (non R2T for the initial data out, R2T
for
the
remaining data).  Is this correct?"
 
really? I thought thatit is permissible to have non-R2T for the initial
data out and R2T for
remaining. i.e for a 64K transfer, the first 32K can be the first burst
size of data and
the next 32K will be solicited by the target through R2T. Am I missing
something?

-Deva

-----Original Message-----
From: Julian Satran [mailto:[email-masked]]
Sent: Wednesday, June 12, 2002 6:05 AM
To: Dennis Young
Cc: [email-masked]; [email-masked]
Subject: Re: iscsi: unsolicited data question

yes - julo 

06/12/2002 06:20 AM 

        To:        [email-masked] 
        cc:         

I have a question which has been asked before, but I couldn't find a
direct 
answer in the archive.  The table on page 200 of draft 12 doesn't
directly
answer this question either.

The first paragraph on page 36 of draft 12 says "Targets operate in
either 
solicitied (R2T) data mode or unsolicited (non R2T) data mode."
tells me that a target, at all times during a data sequence transfer,
can be

one or the other, but not both (non R2T for the initial data out, R2T
for
the
remaining data).  Is this correct?

Thanks,
Dennis

---snip from an old email dated 3/30/2001---

" Hi Julian 
Sorry if I'm covering old ground... Is it possible to use unsolicited
data
for the first burst and then request any remaining data using R2T? For
example, if the target has a previously allocated buffer available
(length
defined by FirstBurstSize) for unsolicited data, then once the initiator
has
sent unsolicited data up to and including this amount then the remaining
data (if any) can be requested using R2T once the target has the buffer
space available. 
...Matthew Burbridge Hewlett Packard, Bristol Telnet: 312 7010 E-mail:
[email-masked] "