RE: is TargetName always mandatory or not?

["Andre Asselin" <asselin@us.ibm.com>]

John,
     The wording you have below, I assume that is for the description of
TargetName in Appendix D, right?  If so, since TargetName isn't required
for a discovery session, could I suggest this wording instead?

        This key must be provided by the initiator of the TCP connection to
        the remote endpoint in the first login request if the initiator is
        not establishing a discovery session.

Also, there are a few other places in the spec that need to be updated to
be consistent with TargetName being required in the leading login of all
normal sessions.

The current version of the 6th paragraph in chapter 5 reads:

The initial Login request of the first connection of a session (leading
login) MUST include the InitiatorName key=value pair. The leading Login
request MAY also include the SessionType key=value pair in which case if
the SessionType is not "discovery" then the leading Login Request MUST
also include the key=value pair TargetName.

A suggested rewrite would be (building on the text suggested by Bob
Russell):


All initial Login requests MUST include the InitiatorName key=value pair.

If the initial Login request is also a leading Login (TSID=0) and the
new session is to be a discovery session, then the initial Login request
MUST also include the SessionType=discovery key=value pair.

If the initial Login request is a leading Login and the new session is to
be a normal session,  then the initial Login request MUST also include
the TargetName key=value pair and MAY also include the SessionType=normal
key=value pair.

All initial Login requests that are not also a leading Login (TSID != 0)
MUST include the TargetName key=value pair.

Also, this text appears in 2.2.7:

        The initiator MUST present both its iSCSI Initiator Name and the
        iSCSI Target Name to which it wishes to connect in the first login
        request of a new session.  The only exception is if a discovery
        session (see 2.4) is to be established; the iSCSI Initiator Name is
        still required, but the iSCSI Target Name may be ignored.  The key
        "SessionType=discovery" is sent by the initiator at login to
indicate
        a discovery session.

A suggested rewrite would be:


        The initiator must present its iSCSI Initiator Name in the first
login
        request.  If the initiator is not establishing a discovery session
(see 2.4), it
        also must present the iSCSI Target Name to which it wishes to
connect in the first login request.
        The key "SessionType=discovery" is sent by the initiator at login
to indicate
        a discovery session. See chapter 5 for a more detailed description
of the login process.

Rationale for making the MUST lowercase: I think specs should state the
MUSTs, MAYs, and SHOULDs in only one place so that a requirement isn't
stated multiple times in slightly different language.  If the powers that
be disagree, then feel free to ignore my opinion...

Andre Asselin
IBM ServeRAID Software Development
Research Triangle Park, NC




                                                                                                                                      
                    John                                                                                                              
                    Hufferd/San          To:     Julian Satran/Haifa/IBM@IBMIL                                                        
                    Jose/IBM@IBMUS       cc:     Jim Hafner/Almaden/IBM@IBMUS, ips@ece.cmu.edu                                        
                    Sent by:             Subject:     RE: is TargetName always mandatory or not?                                      
                    owner-ips@ece.                                                                                                    
                    cmu.edu                                                                                                           
                                                                                                                                      
                                                                                                                                      
                    11/02/2001                                                                                                        
                    02:40 PM                                                                                                          
                                                                                                                                      
                                                                                                                                      




Julian,
I agree with Jim Hafner on this issue.  The Draft should say:

"The TargetName is required on the first login message on every connection
(in all cases, new session or adding connections to existing sessions)."

Also I think we need to change section 3.12.9, which currently says:

"The TSID is the target assigned tag for a session with a specific named
initiator that, together with the ISID uniquely identifies a session with
that initiator".

Should be changed to:

"The TSID is the target assigned tag for a session with a specific named
initiator that, together with the ISID uniquely identifies a session from
that specific target to that specific initiator. That is, the TSID is a
unique value within the scope of a specific Target (Not necessarily Unique
within the iSCSI Target Network Entity)."

.
.
.
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
Internet address: hufferd@us.ibm.com


Jim Hafner/Almaden/IBM@IBMUS@ece.cmu.edu on 11/02/2001 08:04:03 AM

Sent by:  owner-ips@ece.cmu.edu


To:   ips@ece.cmu.edu
cc:
Subject:  RE: is TargetName always mandatory or not?




Folks,

I think this thread may be exposing either an ambiguity in the draft or
perhaps a gap.

I think it's possible to interpret the requirement that TargetName be
supplied (for normal sessions) only on the *first login message on the
first connection of a new session* and is not required on the *first login
message of subsequent connections intended for the same session". My
personal interpretation is that the TargetName is required on the *first
login message on every connection (in all cases, new session or adding
connections to existing sessions)*.  I also think Andre's example of a
network entity containing many iSCSI targets with shared network portals
(and the scoping of portal group tags and TSIDs by iSCSI target) points out
the need for the more restrictive requirement (and the rest of my response
to Andre assumed this).

But I've heard other comments that can be interpreted as the less
restrictive requirement is what is intended.

So, I suggest (and I don't think this is asking much) that the requirement
be that TargetName be supplied on the first Login message of every
connection (not just the leading one).

Jim Hafner