RE: iSCSI Change - New NOP-Out/In text

["Wheat, Stephen R" <stephen.r.wheat@intel.com>]

Julian,

As a relatively new reader of all this good material, perhaps some "new
eyes" editorial questions/suggestions are of value.  My apologies up front
if this doesn't meet with the WG protocol for such suggestions.

Stephen

-----Original Message-----
From: Julian Satran [mailto:Julian_Satran@il.ibm.com]
Sent: Thursday, August 16, 2001 8:09 AM
To: ips@ece.cmu.edu
Subject: iSCSI Change - New NOP-Out/In text
   
+++ srw
The first two paragraphs intermix rational and specification for a "ping
command".
Rational is also repeated.
For brevity and clarity, I suggest striving to keep rational segregated from
semantic definition.

Also, the target's semantics are inconsistent between the NOP-out and NOP-in
paragraphs.

I offer the following text update.

I am willing to do such editorial changes for the rest, but am awaiting
whether the suggestions are valuable.
+++ srw

   A NOP-Out may be sent by an initiator as a "ping command".  This form of
the NOP-Out
   can be used to verify that a connection is still active and all its
components are
   operational.  Based upon whether a corresponding NOP-In is received, this
   provides an initiator a way to determine whether it may be necessary to
   close the connection and try to establish a new connection.

   A NOP-Out is also sent by an initiator in response to a NOP-In.

   A NOP-Out may also be used to confirm a changed ExpStatSN if there is
   no other PDU to carry it for a long time.

   This command MAY use in-order delivery or immediate delivery.

   When used as a ping command, the Initiator Task Tag MUST be set to valid
value (not the
   reserved 0xffffffff).

   Upon receipt of a NOP-In with the
   Target Transfer Tag set to a valid value (not the reserved 0xffffffff),
   the initiator MUST respond with a NOP-Out. In this case the NOP-Out
Target Transfer
   Tag MUST contain a copy of NOP-In Target Task Tag.

   When a target receives the NOP-Out with a
   valid Initiator Task Tag, it MUST respond with a Nop-In Response (see
NOP-in).
                                ^^^^ consider MUST???

1.1.1     Initiator Task Tag

   An initiator assigned identifier for the operation.

   The NOP-Out MUST have the Initiator Task Tag set to a valid value only
   if a response in the form of NOP-In is requested.
   If the Initiator Task Tag does not contain a valid value, the CmdSN
   field contains as usual the next CmdSN but CmdSN is not advanced and the
   I bit must be set to 1.

1.1.2     Target Transfer Tag

   A target assigned identifier for the operation.

   The NOP-Out MUST have the Target Transfer Tag set only if it is issued
   in response to a NOP-In with a valid Target Transfer Tag, in which case
   it copies the Target Transfer Tag from the NOP-In PDU.

   When the Target Transfer Tag is set, the LUN field MUST be also copied
   from the NOP-In.