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Internet Protocol Small Computer System Interface (iSCSI) Cyclic Redundancy Check (CRC)/Checksum Considerations (RFC3385)

IP.com Disclosure Number: IPCOM000009936D
Original Publication Date: 2002-Sep-01
Included in the Prior Art Database: 2002-Oct-01
Document File: 24 page(s) / 53K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

D. Sheinwald: AUTHOR [+4]

Abstract

In this memo, we attempt to give some estimates for the probability of undetected errors to facilitate the selection of an error detection code for the Internet Protocol Small Computer System Interface (iSCSI).

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 5% of the total text.

Network Working Group                                       D. Sheinwald

Request for Comments: 3385                                     J. Satran

Category: Informational                                              IBM

                                                               P. Thaler

                                                              V. Cavanna

                                                                 Agilent

                                                          September 2002

       Internet Protocol Small Computer System Interface (iSCSI)

         Cyclic Redundancy Check (CRC)/Checksum Considerations

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 (2002).  All Rights Reserved.

Abstract

   In this memo, we attempt to give some estimates for the probability

   of undetected errors to facilitate the selection of an error

   detection code for the Internet Protocol Small Computer System

   Interface (iSCSI).

   We will also attempt to compare Cyclic Redundancy Checks (CRCs) with

   other checksum forms (e.g., Fletcher, Adler, weighted checksums), as

   permitted by available data.

1. Introduction

   Cyclic Redundancy Check (CRC) codes [Peterson] are shortened cyclic

   codes used for error detection.  A number of CRC codes have been

   adopted in standards: ATM, IEC, IEEE, CCITT, IBM-SDLC, and more

   [Baicheva].  The most important expectation from this kind of code is

   a very low probability for undetected errors.  The probability of

   undetected errors in such codes has been, and still is, subject to

   extensive studies that have included both analytical models and

   simulations.  Those codes have been used extensively in

   communications and magnetic recording as they demonstrate good "burst

   error" detection capabilities, but are also good at detecting several

   independent bit errors.  Hardware implementations are very simple and

   well known; their simplicity has made them popular with hardware

Sheinwald, et. al.           Informational                      [Page 1]

RFC 3385                iSCSI CRC Considerations          September 2002

   developers for many years.  However, algorithms and software for

   effective implementations of CRC are now also widely available

   [Williams].

   The probability of undetected errors depends on the polynomial

   selected to generate t...