Transmission Control Protocol

Darpa Internet Program
Protocol Ppecification

September 1981
prepared for

Defense Advanced Research Projects Agency
Information Processing Techniques Office
1400 Wilson Boulevard
Arlington, Virginia 22209

by

Information Sciences Institute
University of Southern California
4676 Admiralty Way
Marina del Rey, California 90291
Transmission Control Protocol

TABLE OF CONTENTS

1. INTRODUCTION
   1. Motivation
   2. Scope
   3. About This Document
   4. Interfaces
   5. Operation
2. PHILOSOPHY
   1. Elements of the Internetwork System
   2. Model of Operation
   3. The Host Environment
   4. Interfaces
   5. Relation to Other Protocols
   6. Reliable Communication
   7. Connection Establishment and Clearing
   8. Data Communication
   9. Precedence and Security
   10. Robustness Principle
3. FUNCTIONAL SPECIFICATION
   1. Header Format
   2. Terminology
   3. Sequence Numbers
   4. Establishing a connection
   5. Closing a Connection
   6. Precedence and Security
   7. Data Communication
   8. Interfaces
   9. Event Processing

PREFACE

This document describes the DoD Standard Transmission Control Protocol (TCP). There have been nine earlier editions of the ARPA TCP specification on which this standard is based, and the present text draws heavily from them. There have been many contributors to this work both in terms of concepts and in terms of text. This edition clarifies several details and removes the end-of-letter buffer-size adjustments, and redescribes the letter mechanism as a push function.