This is an on-line course which explains from the user's point of view how and why ISDN works. In addition to this basic theoretical background, it explains some of the practical applications and consequences of these concepts.

You can:

• Navigate from page to page by using the "Next" and "Back" buttons above.
• Navigate between the sections of the course by clicking on the section names to the left.
• Ensure you have the grasped key concepts by answering the questions at the end of each section.
• Use the links provided within the "Practical Applications" page to find out how to apply what you have learned.

Note: This course is copyright � Dialogic Corporation - any reproduction or redistribution of this material is prohibited by law and may result in civil and criminal penalties.