RE: iscsi: unsolicited data question

["Karthik Selvan" <kselvan@marantinetworks.com>]

Title: Message

 

 

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 "