Subject: Multiple targets behind a single IP address

From: [email-masked]
Date: Mon, 9 Apr 2001 12:51:29 -0600

Section 1.2.7 states that WWUIs are used in iSCSI to provide a target
identifier for configurations that present multiple targets behind a single
IP address and port.

To provide this support I would expect the target WWUI to be in the BHS,
but, it does not seem to be there. Is the support missing from the spec?

- Jojy

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From: "KRUEGER,MARJORIE (HP-Roseville,ex1)" <[email-masked]>
Date: Mon, 9 Apr 2001 20:59:54 -0400

The Target Node Address is used in the login phase of the iSCSI protocol.
In order to attempt login, a TCP connection must be first set up.  It is
this connection which is associated with the target when the initiator is
successfully logged in (any PDUs received on that connection are addressed
to the "target the initiator logged into").  There is no connection
association to a target until an initiator is successfully logged in, and
any PDUs received before successful login that are not related to the login
phase (such as a command PDU) should be discarded (not "rejected", since
that could constitute a denial-of-service attack opportunity).

If an initiator is talking to multiple targets behind a single IP address,
it will have at least 1 TCP connection to each target.

The short answer is "the TCP connection is the target identifier" :-)

Marjorie Krueger
Networked Storage Architecture
Networked Storage Solutions Org.
Hewlett-Packard
tel: +1 916 785 2656
fax: +1 916 785 0391
email: [email-masked] 

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]]
> Sent: Monday, April 09, 2001 11:51 AM
> To: [email-masked]
> Subject: Multiple targets behind a single IP address
> 
>

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From: [email-masked]
Date: Tue, 10 Apr 2001 14:29:54 +0300

It has to get once to the target up to the end of the login phase.  Why
should it be in the BHS? Do you have to carry it on every PDU.

Julo

[email-masked] on 09/04/2001 21:51:29

Please respond to [email-masked]

To:   [email-masked]
cc:

- Jojy

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From: "Jim Hafner" <[email-masked]>
Date: Tue, 10 Apr 2001 07:40:13 -0700

Marjorie,

I think I have to ask some questions concerning your quoted statement that
the "TCP connection is the target identifier".    First, the term "target
identifier" is a heavily loaded term in SCSI; is that the sense you meant
it it? Second, how do multiple connections per session, particularly with
connections spanning multiple TCP entities (IPaddresses and IPports) fit in
your picture?  Third, is it the connection itself or the ipaddress/ipport
you're referring to?

Thanks,
Jim Hafner

"KRUEGER,MARJORIE (HP-Roseville,ex1)" <[email-masked]>@ece.cmu.edu
on 04-09-2001 05:59:54 PM

Sent by:  [email-masked]

To:   "[email-masked]'" <[email-masked]>,
      [email-masked]
cc:
Subject:  RE: Multiple targets behind a single IP address

Marjorie Krueger

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From: "KRUEGER,MARJORIE (HP-Roseville,ex1)" <[email-masked]>
Date: Tue, 10 Apr 2001 15:30:32 -0400

Oops, sorry for using that loaded term!  I mean "identifier" in the most
generic way and didn't mean to imply that this is a SCSI target identifier!
I think Jojy was asking what part of the iSCSI PDU indicates which target
this packet is addressed to, and I was trying to convey that the connection
the PDU is received on should provide the association with the target.  You
are correct in pointing out that the association is actually higher than
that, in that a connection is associated with a session, and it's the
session that identifies the target.

To your third point, the connection = ip address+port pair in TCP

Marjorie Krueger

> From: Jim Hafner [mailto:[email-masked]]
> Sent: Tuesday, April 10, 2001 7:40 AM
> To: KRUEGER,MARJORIE (HP-Roseville,ex1); [email-masked]