Signalling Overview

Defining what Signalling is and how and where it is used in networks today. This includes an introduction to several Signalling systems in common use (e.g. Signalling System No. 7 used in the Public Switched Telephone Network.)

Introduction to ISDN

This section introduces the basic concepts behind ISDN and their historical development. The ISDN reference model is introduced here.

Principles of ISDN

Detailed discussion of the reference points used in ISDN, the Basic Rate and Primary Rate Interface frame structures and restrictions on the Passive ‘S’ bus.

ISDN Services

This section focuses on the different Bearer Services, Tele Services and Supplementary Services used in ISDN. The three main ISDN addressing systems are considered, namely Multiple Subscriber Numbering, Direct Dialing In and Sub-Addressing.

Physical Layer

This section concentrates on the lowest layer of the OSI 7 layer Model. It considers the purpose of the Passive ‘S’ bus and it details the framing structure used over it. The section includes the activation procedure over the Passive bus.

Data link Layer

This section concentrates on Layer 2 of the OSI 7 Layer Model. It discusses the functions and procedures of the Data link layer and looks specifically at the Link Access Procedure for the D-Channel.

It reviews the frame format and processes involved with information transfer and looks

to bit level detail at the management messages at this layer.

Network Layer

This section concentrates on Layer 3 of the OSI 7 Layer Model. It discusses the functions and procedures of the Network layer. It looks to bit level at the message structure of a Q. 931 packet format listing the different message types used. The section also considers different formats of Information Elements. After reviewing the different dialing systems used in ISDN it then examines a typical message flow during the set-up and tearing down of a call.

DASS2/DPNSS Overview

An introduction to Digital Private Network Signalling System and its access protocol, Digital Access Signalling System No. 2. It introduces the functions of both Signalling protocols and their historical development. It specifies key standards and interfaces. The section also includes a brief look at the management messages and the message structure used.

Practical Exercises

A total of a full day of practical demonstrations and hands on time with ISDN testers is also included. Exercises cover all features of the testers such as setting up calls, many different tests and capturing and analysing the ISDN messages. Use of an ISDN simulator allows network responses to be seen in a classroom environment.