Subject: RE: [Ips] Login Phase in iSER over IB

From: "John Hufferd" <[email-masked]>
Date: Mon, 15 Aug 2005 11:43:51 -0700

I am OK, with these proposed changes.

.

.

.

John L Hufferd

Sr. Executive Director of Technology

Brocade Communications Systems, Inc

[email-masked]

Office Phone: (408) 333-5244; eFAX: (408) 904-4688

Alt Office Phone: (408) 997-6136; Cell: (408) 627-9606

  _____  

From: [email-masked] [mailto:[email-masked]] On Behalf Of
Alex Nezhinsky
Sent: Monday, August 15, 2005 11:20 AM
To: [email-masked]
Subject: [Ips] Login Phase in iSER over IB

I would like to propose some changes for the "iSER over IB" draft
(http://www.ietf.org/internet-drafts/draft-hufferd-iser-ib-00.txt). The
changes being proposed address a group of statements regarding possible
mechanisms of message exchange during the iSER Login Phase in protocols
such as IB. 

The following statement is an example (section 3.1.6): "For LLPs that
have message delivery capability such as [IB], the iSCSI Layer may use
that messaging capability immediately after connection establishment
before enabling iSER-assisted mode."

Because IB as such does not provide streaming capability equivalent to
the plain (not RDMA-enabled) TCP mode in iWARP, a substitute for it
should be found elsewhere. One option is to use the messaging
capabilities provided by the transport layer itself. This is a valid
option because the Login phase exchange is carried out in half-duplex
mode. It can be understood from the previous statement that using two
separate connections for the iSCSI Login and iSER Full-Feature phases is
also allowed. For example, the Login phase is carried out using an IPoIB
connection, while the iSER part is carried out using a separate IB RC
connection. 

In order to clarify that only using a single transport connection is
mandated, the following changes are proposed:

1) In 3.1.6 the third paragraph is to be replaced with:

"And in that same section (4.1) the next to last * paragraph is hereby
replaced with the following: 

    * For a transport layer that operates in stream mode such as TCP,
the RDMA-Capable Protocol implementation supports the enabling of the
RDMA mode after Connection establishment and the exchange of Login
parameters in stream mode. For a transport layer that provides message
delivery capability, such as [IB], the RDMA-Capable Protocol
implementation supports the use of this messaging capability by the
iSCSI Layer directly for the Login phase after connection establishment
before enabling iSER-assisted mode."

2) In 3.1.6.1 the first paragraph is to be repaced with:

"For a transport layer that provides message delivery capability, such
as [IB], the iSCSI Layer MUST interact with the transport layer directly
to use the messaging capability for exchanging the iSCSI Login Request
and Login Response PDUs. The method for establishing the actual
connection is protocol specific and outside the scope of this
specification. The same connection MUST be used for both the iSCSI Login
phase and the subsequent iSER-supported Full-Feature phase.

Alexander Nezhinsky

Software Engineer

Infiniband Storage Solutions

www.voltaire.com <http://www.voltaire.com/> 

9 Ha-Menofim, Herzelya 46725 Israel

tel: +972- 9- 9717637

fax: +972- 9- 9717660

mobile: +972-50-7504376

_______________________________________________
Ips mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/ips