CONTENTS

  Title Page

  Copyright Page

  Preface

  1      Preparations for Problem Solving

  1.1     Introduction

  1.2     Problem Solving Tools
    1.2.1      NCL
    1.2.2      Event Logging
    1.2.3      Counters
    1.2.4      Common Trace Facility (CTF)
    1.2.5      Loopback Tests

  1.3     Solving a Problem - General Procedure

  2      X.25 Problems

  2.1     Introduction

  2.2     General Procedure

  2.3     Event Messages

  2.4     X.25 Fails to Run After System Reboot

  2.5     DEC X25gateway Does Not Load

  2.6     Local DTE Fails
    2.6.1      DTE Restart Failure
      2.6.1.1      LAPB Links
      2.6.1.2      LLC2 Links
    2.6.2      LAPB Link Set Up Failure
      2.6.2.1      Physical Line Set Up Failure
    2.6.3      LLC2 Link Set Up Failure

  2.7     Incoming Calls Cannot be Received on a Local DTE

  2.8     Incoming Calls Cannot be Received on Client Systems

  2.9     Outgoing Calls Cannot be Made on a Local DTE

  2.10    User Application Programs Fail

  2.11    Virtual Circuit Fails

  3      X.29 and PAD Problems

  3.1     Introduction

  3.2     SET HOST/X29 Does Not Work

  3.3     An Established X.29 Call Clears Unexpectedly

  3.4     X.29 Applications Fail to Connect

  3.5     X.29 Calls Clear Unexpectedly on a Host System

  A   Loopback Testing

  A.1     Testing the Modem Connect Line

  B   Clear Cause Codes

  C   Diagnostic Codes

  D   Reporting Problems to Digital

  D.1     Introduction

  D.2     Details of the Software

  D.3     Details of the Problem

  D.4     Copying System Dump Files

  FIGURES

  A-1        Data Path in Driver and Loopback Modes

  TABLES

  2-1        Event Messages

  B-1        Clear Cause Codes

  C-1        X.25 Diagnostic Codes