Telephony systems

This course provides an introduction to the principles and operation of circuit-switched telephony as used in the Public Switched Telephone Network (PSTN). Fundamental issues that are also relevant to Voice over IP services are discussed.

By the end of this course you will be able to:

• describe the components and structure of the PSTN, the functional elements of an exchange and numbering in the PSTN.
• describe the role and principles of signalling inc. channel associated and common channel signalling.
• describe the structure and components of the local access network.
• describe the role of the various signalling conditions on the local loop with reference to DTMF and Calling Line Identity (CLI).
• describe the role of, and relationship between, the various protocols used by the common channel signalling system number 7 (C7) for inter-exchange signalling.
• explain the role of the various ISUP signalling messages involved in call set-up including the IAM and ACM messages.
• describe the services provided by, and the operation of, the Intelligent Network.
• explain the objectives of teletraffic engineering and describe the parameters used in
• assessing the service offered by a telephony system.

This online course includes assessments, the results of which are summarised in a certificate published at course completion.