CONTENTS

�1���� Introduction
�2���� Scope
�3���� Definitions
�4���� Characteristics of protective components
�5���� Origin of overvoltages and overcurrents
�6���� Strategies for protection of telecommunication systems
�7���� Desirable electrical characteristics
������� 7.1���� Normal operation of the system
������� 7.2���� SPD operating conditions
������� 7.3���� Current-limiting devices
������� 7.4���� Isolating devices
�8���� Failure modes
������� 8.1���� Clamping devices
� ������8.2���� Current-limiting device
�9���� Location and mounting of SPDs
10���� Safety aspects
11���� General aspects on costs for installation and maintenance