DA: Datamover Architecture for the Internet Small Computer System Interface (iSCSI)
RFC 5047
Document | Type |
RFC - Informational
(October 2007; No errata)
Updated by RFC 7146
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Authors | John Hufferd , Hemal Shah , Mallikarjun Chadalapaka , Julian Satran | ||
Last updated | 2015-10-14 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 5047 (Informational) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Lars Eggert | ||
Send notices to | (None) |
Network Working Group M. Chadalapaka Request for Comments: 5047 HP Category: Informational J. Hufferd Brocade Inc. J. Satran IBM H. Shah Broadcom Corporation October 2007 DA: Datamover Architecture for the Internet Small Computer System Interface (iSCSI) Status of This Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Abstract The Internet Small Computer System Interface (iSCSI) is a SCSI transport protocol that maps the SCSI family of application protocols onto TCP/IP. Datamover Architecture for iSCSI (DA) defines an abstract model in which the movement of data between iSCSI end nodes is logically separated from the rest of the iSCSI protocol in order to allow iSCSI to adapt to innovations available in new IP transports. While DA defines the architectural functions required of the class of Datamover protocols, it does not define any specific Datamover protocols. Each such Datamover protocol, defined in a separate document, provides a reliable transport for all iSCSI PDUs, but actually moves the data required for certain iSCSI PDUs without involving the remote iSCSI layer itself. This document begins with an introduction of a few new abstractions, defines a layered architecture for iSCSI and Datamover protocols, and then models the interactions within an iSCSI end node between the iSCSI layer and the Datamover layer that happen in order to transparently perform remote data movement within an IP fabric. It is intended that this definition will help map iSCSI to generic Remote Direct Memory Access (RDMA)-capable IP fabrics in the future comprising TCP, the Stream Control Transmission Protocol (SCTP), and possibly other underlying network transport layers, such as InfiniBand. Chadalapaka, et al. Informational [Page 1] RFC 5047 DA October 2007 Table of Contents 1. Motivation ......................................................4 1.1. Intent .....................................................4 1.2. Interpretation of Requirements .............................5 2. Definitions and Acronyms ........................................5 2.1. Definitions ................................................5 2.2. Acronyms ...................................................6 3. Architectural Layering of iSCSI and Datamover Layers ............7 4. Design Overview .................................................9 5. Architectural Concepts .........................................10 5.1. iSCSI PDU Types ...........................................10 5.1.1. iSCSI Data-Type PDUs ...............................10 5.1.2. iSCSI Control-Type PDUs ............................11 5.2. Data_Descriptor ...........................................11 5.3. Connection_Handle .........................................11 5.4. Operational Primitive .....................................12 5.5. Transport Connection ......................................13 6. Datamover Layer and Datamover Protocol .........................13 7. Functional Overview ............................................14 7.1. Startup ...................................................14 7.2. Full Feature Phase ........................................15 7.3. Wrap-up ...................................................15 8. Operational Primitives Provided by the Datamover Layer .........16 8.1. Send_Control ..............................................16 8.2. Put_Data ..................................................17 8.3. Get_Data ..................................................17 8.4. Allocate_Connection_Resources .............................18 8.5. Deallocate_Connection_Resources ...........................19 8.6. Enable_Datamover ..........................................19 8.7. Connection_Terminate ......................................20 8.8. Notice_Key_Values .........................................20 8.9. Deallocate_Task_Resources .................................20 9. Operational Primitives Provided by the iSCSI Layer .............21 9.1. Control_Notify ............................................21Show full document text