RE: iSCSI: NOP-In

["John Hufferd" <hufferd@us.ibm.com>]

Eddy, et.al.
Initiators can not originate a ping with data.  But it can echo a ping with
data.  That is, it can reflect back to the initiator, via a NOP-In, the
data that was sent to it within a NOP-Out from the initiator.  However, the
target may not originate a ping via a NOP-In and include Data.

This was done, if I remember the history correctly, because initiators are
never prepared to accept unsolicited data of any kind.  They always solicit
data if they are to receive it.  Hence, an unsolicited NOP-In with data,
seemed to some to be problematical, and that capability was removed.

.
.
.
John L. Hufferd
Senior Technical Staff Member (STSM)
IBM/SSG San Jose Ca
Main Office (408) 256-0403, Tie: 276-0403,  eFax: (408) 904-4688
Home Office (408) 997-6136, Cell: (408) 499-9702
Internet address: hufferd@us.ibm.com


Eddy Quicksall <eddyq@ivivity.com> on 05/13/2002 05:21:11 AM

To:    Julian Satran/Haifa/IBM@IBMIL
cc:    ips <ips@ece.cmu.edu>, John Hufferd/San Jose/IBM@IBMUS
Subject:    RE: iSCSI: NOP-In






Maybe I misunderstood John's statement. John, aren't you saying that the
target is not allowed to send ping data at all (i.e., that is MUST always
use  0xFFFFFFFF in the TTT)?


My implied (though perhaps not so well written)
point was that a ping  INITIATED by the target


Eddy

-----Original Message-----
From: Julian Satran  [mailto:Julian_Satran@il.ibm.com]
Sent: Monday, May 13, 2002 1:56  AM
To: Eddy Quicksall
Cc: ips; John Hufferd;  owner-ips
Subject: RE: iSCSI: NOP-In



The implied use for data is to echo it. Julo


                                                                          
     Eddy Quicksall                                                       
     <eddyq@ivivity.com                To:         John Hufferd/San       
     >                         Jose/IBM@IBMUS, Julian                     
                               Satran/Haifa/IBM@IBMIL                     
     05/13/2002 03:28                   cc:        ips                    
     AM                        <ips@ece.cmu.edu>, owner-ips               
     Please respond to         <owner-ips@ece.cmu.edu>,  "\"\"Robert D.   
     Eddy Quicksall            Russell\" <rdr\""                          
                                       Subject:         RE: iSCSI: NOP-In 
                                                                          
                                                                          
                                                                          



BTW, What is the reason for a Target Ping not to  carry any data?

Eddy

-----Original Message-----
From: John  Hufferd [mailto:hufferd@us.ibm.com]
Sent: Sunday, May 12, 2002 3:10  PM
To: Julian Satran
Cc: ips; owner-ips; ""Robert D. Russell"  <rdr"
Subject: Re: iSCSI: NOP-In



Julian,
you are of  course correct.  My implied (though perhaps not so well
written)
point  was that a ping INITIATED by the target, is also possible, but can
not have  data.  And that the removal of the word "ping" would perhaps
prevent  that concept from being obvious.

.
.
.
John L.  Hufferd
Senior Technical Staff Member (STSM)
IBM/SSG San Jose Ca
Main  Office (408) 256-0403, Tie: 276-0403,  eFax: (408) 904-4688
Home  Office (408) 997-6136, Cell: (408) 499-9702
Internet address:  hufferd@us.ibm.com


Julian Satran@IBMIL
05/12/2002 04:47  AM

To:    John Hufferd/San Jose/IBM@IBMUS@IBMDE
cc:     ips@ece.cmu.edu, owner-ips@ece.cmu.edu, "Robert D. Russell"
       <rdr@io.iol.unh.edu>
From:  Julian  Satran/Haifa/IBM@IBMIL
Subject:    Re: iSCSI: NOP-In   (Document link: John Hufferd)

John.

Ping from target is  prohibited from having data only if  TTT is
0xfffffffff
i.e., when no  reply request is requested.

Julo




                       John

                      Hufferd@IBMUS            To:       "Robert D.
Russell"
<rdr@io.iol.unh.edu>
                                                cc:       Julian
Satran/Haifa/IBM@IBMIL, ips@ece.cmu.edu,
                      05/10/2002 12:53          <owner-ips@ece.cmu.edu>

                      AM                        From:     John Hufferd/San
Jose/IBM@IBMUS
                                                Subject: Re: iSCSI:
NOP-In(Document  link: Julian Satran - Mail)















You may  be correct, but I think we need to use the Ping word, so that it
becomes  obvious, as it does now, that Ping from Initiator can have data
but
ping  from Target can not.

.
.
.
John L. Hufferd
Senior Technical  Staff Member (STSM)
IBM/SSG San Jose Ca
Main Office (408) 256-0403, Tie:  276-0403,  eFax: (408) 904-4688
Home Office (408) 997-6136, Cell: (408) 499-9702
Internet address:  hufferd@us.ibm.com