SS7 Basics, Second Edition
This guidebook provides an overview of SS7 technologies, how they are structured, and why they are important.
TABLE OF CONTENTS SS7 Basics, Second Edition
Chapter 1: SS7 Defined
Common Channel Signaling is a signaling method in which a signaling channel conveys, by means of labeled messages, signaling information relating to call setup, control, network management, and network maintenance. Examples of Common Channel Signaling systems are CCITT Signaling System No. 7 and various national versions such as ANSI SS7 as originated by the original Bell Communications Research (now named Telcordia Technologies) and AT&Ts original SS6 and SS7 standards.
The Need for SS7
Worldwide telephone networks are undergoing significant changes as methods of call processing and network management are altered to provide new services and to streamline operations. These changes are driven by user demand for enhanced services and the corresponding efforts of telephone operating companies to satisfy current and future needs. Enhanced services require bi-directional signaling capabilities, flexibility of call setup, and remote database access.
Earlier signaling systems lacked the sophistication required to deliver much more than POTS (Plain Old Telephone Service). These traditional systems use dial pulses and multi-frequency (MF) tones to transmit call and circuit-related information such as dialed digits and circuit busy/idle states.
The complexity of adding new functionality to traditional signaling systems meant that a new network signaling architecture was needed. SS7 was developed to satisfy the telephone operating companies requirements for an improvement to existing signaling systems.
Basic SS7 Network Architecture
A telecommunications network consists of a number of switches and application processors interconnected by transmission circuits. The SS7 network exists within, the telecommunications network and controls it.
Copyright APDG Publishing 2002 under license agreement with Books24x7
