[Ips] IPS WG Last Call Complete: iSER revisions
Black_David@emc.com Tue, 11 October 2005 16:06 UTC
Received: from localhost.localdomain ([127.0.0.1] helo=megatron.ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1EPMdh-0006W6-U3; Tue, 11 Oct 2005 12:06:05 -0400
Received: from odin.ietf.org ([132.151.1.176] helo=ietf.org) by megatron.ietf.org with esmtp (Exim 4.32) id 1EPMdh-0006W0-28 for ips@megatron.ietf.org; Tue, 11 Oct 2005 12:06:05 -0400
Received: from ietf-mx.ietf.org (ietf-mx [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id MAA11522 for <ips@ietf.org>; Tue, 11 Oct 2005 12:06:02 -0400 (EDT)
From: Black_David@emc.com
Received: from mailhub.lss.emc.com ([168.159.2.31]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1EPMnp-00081U-Iz for ips@ietf.org; Tue, 11 Oct 2005 12:16:33 -0400
Received: from mxic2.corp.emc.com (mxic2.corp.emc.com [128.221.12.9]) by mailhub.lss.emc.com (Switch-3.1.6/Switch-3.1.6) with ESMTP id j9BG5t8L027642 for <ips@ietf.org>; Tue, 11 Oct 2005 12:05:58 -0400 (EDT)
Received: by mxic2.corp.emc.com with Internet Mail Service (5.5.2653.19) id <RT6A7ACH>; Tue, 11 Oct 2005 12:05:50 -0400
Message-ID: <F222151D3323874393F83102D614E0557A6FBB@CORPUSMX20A.corp.emc.com>
To: ips@ietf.org
Date: Tue, 11 Oct 2005 12:05:46 -0400
MIME-Version: 1.0
X-Mailer: Internet Mail Service (5.5.2653.19)
Content-Type: text/plain
X-PMX-Version: 4.7.1.128075, Antispam-Engine: 2.1.0.0, Antispam-Data: 2005.10.11.16
X-PerlMx-Spam: Gauge=, SPAM=0%, Reasons='EMC_BODY_1+ -5, EMC_FROM_00+ -3, NO_REAL_NAME 0, __C230066_P5 0, __CT 0, __CT_TEXT_PLAIN 0, __HAS_MSGID 0, __HAS_X_MAILER 0, __IMS_MSGID 0, __IMS_MUA 0, __MIME_TEXT_ONLY 0, __MIME_VERSION 0, __SANE_MSGID 0, __STOCK_CRUFT 0'
X-Spam-Score: 0.3 (/)
X-Scan-Signature: 5d7a7e767f20255fce80fa0b77fb2433
Subject: [Ips] IPS WG Last Call Complete: iSER revisions
X-BeenThere: ips@ietf.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: IP Storage <ips.ietf.org>
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/ips>, <mailto:ips-request@ietf.org?subject=unsubscribe>
List-Post: <mailto:ips@ietf.org>
List-Help: <mailto:ips-request@ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/ips>, <mailto:ips-request@ietf.org?subject=subscribe>
Sender: ips-bounces@ietf.org
Errors-To: ips-bounces@ietf.org
First of all, this message announces the conclusion of the WG Last Call on the iSER changes to support non-iWARP RDMA transports, such as InfiniBand. I have a number of editorial changes below that will require further editing, but not another WG Last Call. Also, the proposed editing changes to iSER introduced some technical changes: - RDMA Read after an RDMA Write on the same stream must be strictly ordered by the RDMA protocol. (Section 4.1, 3rd item) - Generalization of login phase description to allow use of a non-byte-stream messaging protocol. (Section 4.1, next to last item, and a few other places). - Failure to negotiate iSER may cause connection close in order to restart traditional iSCSI over TCP/IP (Section 5.1, end of 2nd paragraph). While I believe all of these changes have been discussed in the past, for process purposes, as WG chair, I believe that it is the rough consensus of the IP Storage WG that these technical changes should be made to the iSER draft. See: http://www.haifa.il.ibm.com/satran/ips/draft-ietf-ips-iser-05_candidate.txt Anyone who disagrees needs to post to the list ASAP with a technical rationale for their disagreement. On to the editorial changes that are needed: -- (1) Motivation text has a gap -- The generalization of the iSER text to support InfiniBand has exposed a problem in the Motivation section (2.1) of the iSER draft - the discussion jumps from SNIC to generic RDMA capable controller without explaining why. To address this, the following text: With these defined techniques in [RFC3720], a Network Interface Controller customized for iSCSI (SNIC) could offload the TCP/IP processing and support direct data placement. Supporting direct data placement is the main function of an RDMA Capable Protocol (RCP). should be changed to: With these defined techniques in [RFC3720], a Network Interface Controller customized for iSCSI (SNIC) could offload the TCP/IP processing and support direct data placement, but most iSCSI implementations do not support iSCSI "markers", making SNIC marker-based direct data placement unusable in practice. The iWARP protocol stack provides direct data placement functionality that is usable in practice, and in addition, there is also interest in using iSCSI with other RDMA protocol stacks that support direct data placement, such as the one provided by InfiniBand. The generic term RDMA-Capable Protocol is used to refer to the RDMA functionality provided by such protocol stacks. -- (2) RCP acronym is a problem -- While the acronym RCP for RDMA-Capable Protocol is correct, it detracts from readability. A lot of people will initially mis-read it as the Unix remote copy utility (e.g., see item 6. in Section 2.2, Architectural Goals). The generic term "RDMA" should be substituted for "RCP" in phrases such as "RDMA functionality", "RDMA messages", "RDMA services", "RDMA layer" etc. to eliminate the RCP acronym, or at least greatly reduce its use. -- (3) RDMA Capable Protocol needs to be generic --- There are several issues here, all of which revolve around the fact that RDMA Capable Protocols are not specified by iSER, and the iSER draft needs to accommodate new ones that haven't been designed, yet. - Section 2.3, item 6. Change "RCP guarantees data integrity." to "The RCP MUST ensure data integrity." or "The RCP is responsible for ensuring data integrity." This draft does not specify any RCP. Section 5.1, top of p.33. Same problem: "RCP provides error detection based on 32-bit CRC for all iSER Messages." This needs to be generalized to say that the RCP MUST or is responsible for providing error detection that is at least as good as a 32-bit CRC. RCP or whatever wording replaces it needs to be generic - go over the draft and pretend that there was an RDMA over carrier pigeon protocol and make sure that none of the wording would need to change to support trying to run iSER over that ... well, maybe not RDMA over carrier pigeon, but perhaps something like RDMA over MPEG (not as ridiculous as it sounds, as MPEG is the link format for some satellite links). -- (4) Other minor stuff -- The text describing InfiniBand seems to be ok, even the use of InfiniBand in Figure 1. Section 14.4 comes closest to the line, but it's probably ok. Section 7.3.9 needs to explain the else case for "If the underlying transport is TCP," The byte-stream requirement is applicable only to TCP, but the location of this phrase at the start of this section could make the entire paragraph or section applicable only to TCP. The other places that use this phrasing don't appear to have analogous problems, but should be double-checked. Delete the [VERBS] reference, as that draft has expired and will not become an RFC. If that's not acceptable, reference an RDMAC verbs draft in a publicly available place. -- Next Step -- The iSER authors should prepare and submit a -05 draft in accordance with the above guidance (including the rough consensus of the RDDP WG on the technical changes). Please make sure the draft passes the draft checker at http://tools.ietf.org/tools/idnits/idnits.pyht before submitting. Thanks, --David ---------------------------------------------------- David L. Black, Senior Technologist EMC Corporation, 176 South St., Hopkinton, MA 01748 +1 (508) 293-7953 FAX: +1 (508) 293-7786 black_david@emc.com Mobile: +1 (978) 394-7754 ---------------------------------------------------- _______________________________________________ Ips mailing list Ips@ietf.org https://www1.ietf.org/mailman/listinfo/ips
- [Ips] IPS WG Last Call Complete: iSER revisions Black_David
- Re: [Ips] IPS WG Last Call Complete: iSER revisio… Mallikarjun C.
- RE: [Ips] IPS WG Last Call Complete: iSER revisio… Black_David