RE: iscsi: unsolicited data question

["Julian Satran" <Julian_Satran@il.ibm.com>]

OK Julo

"Karthik Selvan" <kselvan@marantinetworks.com> Sent by: owner-ips@ece.cmu.edu 06/14/2002 11:56 AM Please respond to "Karthik Selvan"

To:        "'BURBRIDGE,MATTHEW \(HP-UnitedKingdom,ex2\)'" <matthew_burbridge@hp.com>, "'Arul Ponnusamy'" <aponnusamy@corp.iready.com>, "'Ranganathan, Deva'" <Deva_Ranganathan@adaptec.com>, Julian Satran/Haifa/IBM@IBMIL         cc:        <ips@ece.cmu.edu>         Subject:        RE: iscsi: unsolicited data question

Hi,

1) Your table looks great. 

Thanks
Karthik selvan

Hi all,

There are two forms of unsolicited data: "Immediate Data" and
"Unsolicited Data Out PDUs".

The text in section 11.12 is correct and is backed up by the table.

However, the table may be improved my changing it thus:
+----------+-------------+------------------+--------------+
|InitialR2T|ImmediateData|Accept Unsolicited|   Accept     |
|          |             |   Data Out PDUs  |Immediate Data|
+----------+-------------+------------------+--------------+
| No       | No          | Yes              | No           |
+----------+-------------+------------------+--------------+
| No       | Yes         | Yes              | Yes          |
+----------+-------------+------------------+--------------+
| Yes      | No          | No               | No           |
+----------+-------------+------------------+--------------+
| Yes      | Yes         | No               | Yes          |
+----------+-------------+------------------+--------------+

Cheers

Matthew Burbridge


-----Original Message-----
From: Karthik Selvan [mailto:kselvan@marantinetworks.com]
Sent: Friday, June 14, 2002 9:22 AM
To: 'Arul Ponnusamy'; 'Ranganathan, Deva'; 'Julian Satran'
Cc: ips@ece.cmu.edu
Subject: RE: iscsi: unsolicited data question



Hi,

1) In draft 12.98, Page no : 215, line 14 says
"If ImmediateData is set to Yes and InitialR2t is to Yes(default), then
only immediate data are accepted in the first burst."

2) Page 216 table uses "Immediate unsolicited data only".

3)  whenever  there is a difference between text and the table in std.
documents, we have to follow the text.

4)  Julo may solve this in next draft or he may clarify more in the
mailing list.

Hope this helps
karthik selvan

-----Original Message-----
From: Arul Ponnusamy [mailto:aponnusamy@corp.iready.com]
Sent: Friday, June 14, 2002 1:12 AM
To: 'Karthik Selvan'; Arul Ponnusamy; 'Ranganathan, Deva'; 'Julian
Satran'
Cc: ips@ece.cmu.edu
Subject: RE: iscsi: unsolicited data question


<karthik> Draft Section 11.12 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)

[Arul Ponnusamy] I think "immediate data" implies that it is
unsolicited. Infact the table in the section 11.12 says explicitly
"Immediate unsolicited data only".


 -----Original Message-----
From: Karthik Selvan [mailto:kselvan@marantinetworks.com]
Sent: Friday, June 14, 2002 12:46 AM
To: 'Arul Ponnusamy'; 'Ranganathan, Deva'; 'Julian Satran'
Cc: ips@ece.cmu.edu
Subject: RE: iscsi: unsolicited data question




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: 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?

<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:Deva_Ranganathan@adaptec.com]
Sent: Thursday, June 13, 2002 6:59 PM
To: 'Julian Satran'
Cc: ips@ece.cmu.edu
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:Julian_Satran@il.ibm.com]
Sent: Wednesday, June 12, 2002 6:05 AM
To: Dennis Young
Cc: ips@ece.cmu.edu; owner-ips@ece.cmu.edu
Subject: Re: iscsi: unsolicited data question



yes - julo


Dennis Young <dyoung@rhapsodynetworks.com>
Sent by: owner-ips@ece.cmu.edu
06/12/2002 06:20 AM
Please respond to Dennis Young
       
        To:        ips@ece.cmu.edu
        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: matthewb@bri.hp.com "