RFC 1323 (rfc1323) – Page 1 of 37

TCP Extensions for High Performance

Alternative Format: Original Text Document

Network Working Group                                        V. Jacobson
Request for Comments: 1323                                           LBL
Obsoletes: RFC 1072, RFC 1185                                  R. Braden
                                                                     ISI
                                                               D. Borman
                                                           Cray Research
                                                                May 1992


                  TCP Extensions for High Performance

Status of This Memo

   This RFC specifies an IAB standards track protocol for the Internet
   community, and requests discussion and suggestions for improvements.
   Please refer to the current edition of the "IAB Official Protocol
   Standards" for the standardization state and status of this protocol.
   Distribution of this memo is unlimited.

Abstract

   This memo presents a set of TCP extensions to improve performance
   over large bandwidth*delay product paths and to provide reliable
   operation over very high-speed paths.  It defines new TCP options for
   scaled windows and timestamps, which are designed to provide
   compatible interworking with TCP's that do not implement the
   extensions.  The timestamps are used for two distinct mechanisms:
   RTTM (Round Trip Time Measurement) and PAWS (Protect Against Wrapped
   Sequences).  Selective acknowledgments are not included in this memo.

   This memo combines and supersedes RFC-1072 and RFC-1185, adding
   additional clarification and more detailed specification.  Appendix C
   summarizes the changes from the earlier RFCs.

TABLE OF CONTENTS

   1.  Introduction .................................................  2
   2.  TCP Window Scale Option ......................................  8
   3.  RTTM -- Round-Trip Time Measurement .......................... 11
   4.  PAWS -- Protect Against Wrapped Sequence Numbers ............. 17
   5.  Conclusions and Acknowledgments .............................. 25
   6.  References ................................................... 25
   APPENDIX A: Implementation Suggestions ........................... 27
   APPENDIX B: Duplicates from Earlier Connection Incarnations ...... 27
   APPENDIX C: Changes from RFC-1072, RFC-1185 ...................... 30
   APPENDIX D: Summary of Notation .................................. 31
   APPENDIX E: Event Processing ..................................... 32
   Security Considerations .......................................... 37



Jacobson, Braden, & Borman