RE: iSCSI: Portal Group clarification

[Eddy Quicksall <eddy_quicksall@ivivity.com>]

Yes.

Note however that a Network Portal can belong to more than one Target Portal
Group but only one Target Portal Group within a single node (which is a
target in this context).

Eddy

-----Original Message-----
From: Kevin Gibbons [mailto:kgibbons@NishanSystems.com] 
Sent: Tuesday, April 01, 2003 6:39 PM
To: ips@ece.cmu.edu
Subject: iSCSI: Portal Group clarification

Hi, I would like to make sure I understand the iSCSI model correctly.  Can
anyone confirm that a Portal, providing access to a target, is part of
exactly one Portal Group at a time?  My reading of the spec indicates this
is true.  That each Portal has a 16 bit Portal Group tag.  But I would like
to make sure.

I believe that in iSCSI draft 20, it states that a Portal can be part of
exactly one Portal Group.  Please see page 15:

   - Portal Groups: iSCSI supports multiple connections within the same
   session; some implementations will have the ability to combine
   connections in a session across multiple Network Portals. A Portal
   Group defines a set of Network Portals within an iSCSI Network
   Entity that collectively supports the capability of coordinating a
   session with connections spanning these portals. Not all Network
   Portals within a Portal Group need participate in every session
   connected through that Portal Group. One or more Portal Groups may
   provide access to an iSCSI Node. Each Network Portal, as utilized by
   a given iSCSI Node, belongs to exactly one portal group within that
   node.

	Also, please see page 39 for similar wording.  There is also a
figure on page 40:

     ----------------------------IP Network---------------------
            |               |                    |
       +----|---------------|-----+         +----|---------+
       | +---------+  +---------+ |         | +---------+  |
       | | Network |  | Network | |         | | Network |  |
       | | Portal  |  | Portal  | |         | | Portal  |  |
       | +--|------+  +---------+ |         | +---------+  |
       |    |               |     |         |    |         |
       |    |    Portal     |     |         |    | Portal  |
       |    |    Group 1    |     |         |    | Group 2 |
       +--------------------------+         +--------------+
            |               |                    |
   +--------|---------------|--------------------|--------------------+
   |        |               |                    |                    |
   |  +----------------------------+  +-----------------------------+ |
   |  | iSCSI Session (Target side)|  | iSCSI Session (Target side) | |
   |  |                            |  |                             | |
   |  |       (TSIH = 56)          |  |       (TSIH = 48)           | |
   |  +----------------------------+  +-----------------------------+ |
   |                                                                  |
   |                     iSCSI Target Node                            |
   |             (within Network Entity, not shown)                   |
   +------------------------------------------------------------------+


Please let me know if I am in error.
	Thanks very much! Kevin

-------------------------------------------------
Kevin Gibbons
Nishan Systems, Inc.
kgibbons@NishanSystems.com
(408) 519-3756
-------------------------------------------------