Enhanced Remote Direct Memory Access (RDMA) Connection Establishment
RFC 6581

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 09

Internet Engineering Task Force (IETF)                  A. Kanevsky, Ed.
Request for Comments: 6581                                     Dell Inc.
Updates: 5043, 5044                                      C. Bestler, Ed.
Category: Standards Track                                Nexenta Systems
ISSN: 2070-1721                                                 R. Sharp
                                                                   Intel
                                                                 S. Wise
                                                     Open Grid Computing
                                                              April 2012

              Enhanced Remote Direct Memory Access (RDMA)
                        Connection Establishment

Abstract

   This document updates RFC 5043 and RFC 5044 by extending Marker
   Protocol Data Unit (PDU) Aligned Framing (MPA) negotiation for Remote
   Direct Memory Access (RDMA) connection establishment.  The first
   enhancement extends RFC 5044, enabling peer-to-peer connection
   establishment over MPA / Transmission Control Protocol (TCP).  The
   second enhancement extends both RFC 5043 and RFC 5044, by providing
   an option for standardized exchange of RDMA-layer connection
   configuration.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by
   the Internet Engineering Steering Group (IESG).  Further
   information on Internet Standards is available in Section 2 of
   RFC 5741.

   Information about the current status of this document, any
   errata, and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6581.

Kanevsky, et al.             Standards Track                    [Page 1]
RFC 6581         Enhanced RDMA Connection Establishment       April 2012

Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Introduction ....................................................3
      1.1. Summary of Changes Affecting RFC 5044 ......................4
      1.2. Summary of Changes Affecting RFC 5043 ......................4
   2. Requirements Language ...........................................4
   3. Definitions .....................................................4
   4. Motivations .....................................................7
      4.1. Standardization of RDMA Read Parameter Configuration .......7
      4.2. Enabling MPA Mode ..........................................9
      4.3. Lack of Explicit RTR in MPA Request/Reply Exchange ........10
      4.4. Limitations on ULP Workaround .............................11
           4.4.1. Transport Neutral APIs .............................11
           4.4.2. Work/Completion Queue Accounting ...................11
           4.4.3. Host-based Implementation of MPA Fencing ...........12
   5. Enhanced MPA Connection Establishment ..........................13
   6. Enhanced MPA Request/Reply Frames ..............................14
   7. Enhanced SCTP Session Control Chunks ...........................15
   8. MPA Error Reporting ............................................16
   9. Enhanced RDMA Connection Establishment Data ....................17
      9.1. IRD and ORD Negotiation ...................................18
      9.2. Peer-to-Peer Connection Negotiation .......................20
      9.3. Enhanced Connection Negotiation Flow ......................21
   10. Interoperability ..............................................21
   11. IANA Considerations ...........................................22
   12. Security Considerations .......................................23
   13. Acknowledgements ..............................................23
   14. References ....................................................23
      14.1. Normative References .....................................23
      14.2. Informative References ...................................24

Kanevsky, et al.             Standards Track                    [Page 2]
RFC 6581         Enhanced RDMA Connection Establishment       April 2012

1.  Introduction

   When used over the Transmission Control Protocol (TCP), the current