Internet Small Computer System Interface (iSCSI) Corrections and Clarifications
RFC 5048
| Document | Type |
RFC - Proposed Standard
(October 2007; No errata)
Obsoleted by RFC 7143
Updated by RFC 7146
Updates RFC 3720
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 5048 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Lars Eggert | ||
| Send notices to | (None) | ||
Network Working Group M. Chadalapaka, Ed.
Request for Comments: 5048 Hewlett-Packard Co.
Updates: 3720 October 2007
Category: Standards Track
Internet Small Computer System Interface (iSCSI)
Corrections and Clarifications
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Abstract
The Internet Small Computer System Interface (iSCSI) is a SCSI
transport protocol and maps the SCSI architecture and command sets
onto TCP/IP. RFC 3720 defines the iSCSI protocol. This document
compiles the clarifications to the original protocol definition in
RFC 3720 to serve as a companion document for the iSCSI implementers.
This document updates RFC 3720 and the text in this document
supersedes the text in RFC 3720 when the two differ.
Table of Contents
1. Introduction ....................................................3
2. Definitions, Acronyms, and Document Summary .....................3
2.1. Definitions ................................................3
2.2. Acronyms ...................................................4
2.3. Clarifications, Changes, and New Semantics .................5
3. iSCSI Semantics for SCSI Tasks ..................................7
3.1. Residual Handling ..........................................7
3.1.1. Overview ............................................7
3.1.2. SCSI REPORT LUNS and Residual Overflow ..............7
3.2. R2T Ordering ...............................................9
3.3. Model Assumptions for Response Ordering ....................9
3.3.1. Model Description ..................................10
3.3.2. iSCSI Semantics with the Interface Model ...........10
3.3.3. Current List of Fenced Response Use Cases ..........11
4. Task Management ................................................12
4.1. Requests Affecting Multiple Tasks .........................12
4.1.1. Scope of Affected Tasks ............................12
4.1.2. Clarified Multi-Task Abort Semantics ...............13
4.1.3. Updated Multi-Task Abort Semantics .................14
Chadalapaka Standards Track [Page 1]
RFC 5048 iSCSI Corrections and Clarifications October 2007
4.1.4. Affected Tasks Shared across RFC 3720 and
FastAbort Sessions .................................16
4.1.5. Implementation Considerations ......................17
4.1.6. Rationale behind the New Semantics .................17
5. Discovery Semantics ............................................19
5.1. Error Recovery for Discovery Sessions .....................19
5.2. Reinstatement Semantics of Discovery Sessions .............19
5.2.1. Unnamed Discovery Sessions .........................20
5.2.2. Named Discovery Sessions ...........................20
5.3. Target PDUs during Discovery ..............................20
6. Negotiation and Others .........................................21
6.1. TPGT Values ...............................................21
6.2. SessionType Negotiation ...................................21
6.3. Understanding NotUnderstood ...............................21
6.4. Outstanding Negotiation Exchanges .........................22
7. iSCSI Error Handling and Recovery ..............................22
7.1. ITT .......................................................22
7.2. Format Errors .............................................22
7.3. Digest Errors .............................................22
7.4. Message Error Checking ....................................23
8. iSCSI PDUs .....................................................23
8.1. Asynchronous Message ......................................23
8.2. Reject ....................................................24
9. Login/Text Operational Text Keys ...............................24
9.1. TaskReporting .............................................24
10. Security Considerations .......................................25
11. IANA Considerations ...........................................26
11.1. iSCSI-Related IANA Registries ............................26
11.2. iSCSI Opcodes ............................................26
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