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Remote Direct Memory Access (RDMA) over IP Problem Statement (RFC4297)

IP.com Disclosure Number: IPCOM000132153D
Original Publication Date: 2005-Dec-01
Included in the Prior Art Database: 2005-Dec-03
Document File: 21 page(s) / 48K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

A. Romanow: AUTHOR [+4]

Abstract

Overhead due to the movement of user data in the end-system network I/O processing path at high speeds is significant, and has limited the use of Internet protocols in interconnection networks, and the Internet itself -- especially where high bandwidth, low latency, and/or low overhead are required by the hosted application.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 6% of the total text.

Network Working Group                                         A. Romanow
Request for Comments: 4297                                         Cisco
Category: Informational                                         J. Mogul
                                                                      HP
                                                               T. Talpey
                                                                  NetApp
                                                               S. Bailey
                                                               Sandburst
                                                           December 2005


      Remote Direct Memory Access (RDMA) over IP Problem Statement

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.

Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract

   Overhead due to the movement of user data in the end-system network
   I/O processing path at high speeds is significant, and has limited
   the use of Internet protocols in interconnection networks, and the
   Internet itself -- especially where high bandwidth, low latency,
   and/or low overhead are required by the hosted application.

   This document examines this overhead, and addresses an architectural,
   IP-based "copy avoidance" solution for its elimination, by enabling
   Remote Direct Memory Access (RDMA).

Romanow, et al.              Informational                      [Page 1]
RFC 4297             RDMA over IP Problem Statement        December 2005


Table of Contents

   1. Introduction ....................................................2
   2. The High Cost of Data Movement Operations in Network I/O ........4
      2.1. Copy avoidance improves processing overhead. ...............5
   3. Memory bandwidth is the root cause of the problem. ..............6
   4. High copy overhead is problematic for many key Internet
      applications. ...................................................8
   5. Copy Avoidance Techniques ......................................10
      5.1. A Conceptual Framework: DDP and RDMA ......................11
   6. Conclusions ....................................................12
   7. Security Considerations ...........................................