Marker PDU Aligned Framing for TCP Specification
RFC 5044

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Network Working Group                                          P. Culley
Request for Comments: 5044                       Hewlett-Packard Company
Category: Standards Track                                       U. Elzur
                                                    Broadcom Corporation
                                                                R. Recio
                                                         IBM Corporation
                                                               S. Bailey
                                                   Sandburst Corporation
                                                              J. Carrier
                                                               Cray Inc.
                                                            October 2007

            Marker PDU Aligned Framing for TCP Specification

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

   Marker PDU Aligned Framing (MPA) is designed to work as an
   "adaptation layer" between TCP and the Direct Data Placement protocol
   (DDP) as described in RFC 5041.  It preserves the reliable, in-order
   delivery of TCP, while adding the preservation of higher-level
   protocol record boundaries that DDP requires.  MPA is fully compliant
   with applicable TCP RFCs and can be utilized with existing TCP
   implementations.  MPA also supports integrated implementations that
   combine TCP, MPA and DDP to reduce buffering requirements in the
   implementation and improve performance at the system level.

Culley, et al.              Standards Track                     [Page 1]
RFC 5044                  MPA Framing for TCP               October 2007

Table of Contents

   1. Introduction ....................................................4
      1.1. Motivation .................................................4
      1.2. Protocol Overview ..........................................5
   2. Glossary ........................................................8
   3. MPA's Interactions with DDP ....................................11
   4. MPA Full Operation Phase .......................................13
      4.1. FPDU Format ...............................................13
      4.2. Marker Format .............................................14
      4.3. MPA Markers ...............................................14
      4.4. CRC Calculation ...........................................16
      4.5. FPDU Size Considerations ..................................21
   5. MPA's interactions with TCP ....................................22
      5.1. MPA transmitters with a standard layered TCP ..............22
      5.2. MPA receivers with a standard layered TCP .................23
   6. MPA Receiver FPDU Identification ...............................24
   7. Connection Semantics ...........................................24
      7.1. Connection Setup ..........................................24
           7.1.1. MPA Request and Reply Frame Format .................26
           7.1.2. Connection Startup Rules ...........................28
           7.1.3. Example Delayed Startup Sequence ...................30
           7.1.4. Use of Private Data ................................33
                  7.1.4.1. Motivation ................................33
                  7.1.4.2. Example Immediate Startup Using
                           Private Data ..............................35
           7.1.5. "Dual Stack" Implementations .......................37
      7.2. Normal Connection Teardown ................................38
   8. Error Semantics ................................................39
   9. Security Considerations ........................................40
      9.1. Protocol-Specific Security Considerations .................40
           9.1.1. Spoofing ...........................................40
                  9.1.1.1. Impersonation .............................41
                  9.1.1.2. Stream Hijacking ..........................41
                  9.1.1.3. Man-in-the-Middle Attack ..................41
           9.1.2. Eavesdropping ......................................42
      9.2. Introduction to Security Options ..........................42
      9.3. Using IPsec with MPA ......................................43
      9.4. Requirements for IPsec Encapsulation of MPA/DDP ...........43
   10. IANA Considerations ...........................................44
   Appendix A. Optimized MPA-Aware TCP Implementations ...............45
      A.1. Optimized MPA/TCP Transmitters ............................46
      A.2. Effects of Optimized MPA/TCP Segmentation .................46