Subject: WG Review IP Storage (ips)

From: The IESG <[email-masked]>
Date: Mon, 11 Sep 2000 07:41:11 -0400

A new IETF working group has been proposed in the Transport Area.
The IESG has not made any determination as yet. 

The following Description was submitted, and is provided for
informational purposes only:

IP Storage (ips)
----------------
 
 Current Status: Proposed Working Group
 
 Transport Area Advisor: 
     Allison Mankin  <[email-masked]>
 
 Mailing Lists: 
     General Discussion:[email-masked]
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     Archive:           http://ips.pdl.cs.cmu.edu/mail/maillist.html
 
Description of Working Group:
 
There is significant interest in using IP-based networks to transport 
block storage traffic.  This group will pursue the pragmatic approach of
encapsulating existing protocols, such as SCSI and Fibre Channel, in an
IP-based transport or transports.  The group will focus on the transport 
or transports and related issues (e.g., security, naming, discovery, and
configuration), as opposed to modifying existing protocols. Standards 
for the protocols to be encapsulated are controlled by other standards
organizations (e.g., T10 [SCSI] and T11 [Fibre Channel]).  The WG cannot
assume that any changes it desires will be made in these standards, and
hence will pursue approaches that do not depend on such changes unless 
they are unavoidable.  In that case the WG will create a document to be 
forwarded to the standards group responsible for the technology 
explaining the issue and requesting the desired changes be considered.  
The WG will endeavor to ensure high quality communications with these 
standards organizations.  The WG will consider whether a layered 
architecture providing common transport, security, and/or other 
functionality for its encapsulations is the best technical approach.

The protocols to be encapsulated expect a reliable transport, in that
failure to deliver data is considered to be a rare event for which
time-consuming recovery at higher levels is acceptable.  This has
implications for both the choice of transport protocols and design of 
the encapsulation(s).  The WG's encapsulations may require quality of 
service assurances (e.g., bounded latency) to operate successfully; the 
WG will consider what assurances are appropriate and how to provide them 
in shared traffic environments (e.g., the Internet) based on existing 
IETF QoS mechanisms such as Differentiated Services.

Use of IP-based transports raises issues that do not occur in the 
existing transports for the protocols to be encapsulated.  The WG will 
address at least the following:

- Congestion control suitable for shared traffic network environments
  such as the Internet.

- Security measures, including authentication and privacy, sufficient
  to defend against threats up to and including those that can be 
  expected on a public network.

- Naming and discovery mechanisms for the encapsulated protocols on
  IP-based networks, including both discovery of resources (e.g.,
  storage) for access by the discovering entity, and discovery for
  management.

- Management, including appropriate MIB definition(s).

The WG will address security and congestion control as an integral part 
of bits protocol encapsulation(s); naming, discovery, and management are
important related issues, but may be addressed in companion documents.

The WG specifications will provide support for bridges and gateways that
connect to existing implementations of the encapsulated protocols. The 
WG will preserve the approaches to discovery, multi-pathing, booting, 
and similar issues taken by the protocols it encapsulates to the extent
feasible.

It may be necessary for traffic utilizing the WG's encapsulations to 
pass through Network Address Translators (NATs) and/or firewalls in some
circumstances; the WG will endeavor to design NAT- and firewall-friendly
protocols that do not dynamically select target ports or require 
Application Level Gateways.

Effective implementations of some IP transports for the encapsulated
protocols are likely to require hardware acceleration; the WG will 
consider issues concerning the effective implementation of its protocols 
in hardware.

The standard internet checksum is weaker than the checksums used by=20 
other implementations of the protocols to be encapsulated.  The WG will 
consider what levels of data integrity assurance are required and how 
they should be achieved.

The WG will produce a framework document that provides an overview of 
the environments in which its encapsulated protocols and related 
protocols are expected to operate.  The WG will produce requirements and 
specification documents for each protocol encapsulation, and may produce 
applicability statements.  The requirements and specification documents 
will consider both disk and tape devices, taking note of the variation 
in scale from single drives to large disk arrays and tape libraries, 
although the requirements and specifications need not encompass all such 
devices.

The WG will not work on:

- Extensions to existing protocols such as SCSI and Fibre Channel beyond
  those strictly necessary for the use of IP-based transports.

- Modifications to internet transport protocols or approaches requiring
  transport protocol options that are not widely supported, although 
  the WG may recommend use of such options for block storage traffic.

- Support for environments in which significant data loss or data
  corruption is acceptable.

- File system protocols.

Operational Structure:

Due to the scope of the task and the need for parallel progress on 
multiple work items, the WG effort is organized as follows:

A technical coordinator will be identified and selected for each 
protocol encapsulation adopted as a work item by the group.  This person 
will be responsible for coordinating the technical efforts of the group 
with respect to that encapsulation, working with and motivating the 
document editors, and evangelizing the group's work within both the 
community and relevant external organizations such as T10 and T11.
 
In addition to the normal responsibilities of IETF working group chairs, 
the IPS chairs hold primary responsibility for selection of 
coordinators, identifying areas of technical commonality and building 
cross-technology efforts within the group.

Coordinators for initially important encapsulations:

SCSI over IP (aka iSCSI): TBD

Fibre Channel (FC-2) over IP: TBD