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178 Chapter 6: Using ISDN and DDR Technologies

Q&A

The questions and scenarios in this book are more difficult than what you should experience on
the actual exam. The questions do not attempt to cover more breadth or depth than the exam;
however, they are designed to make sure that you know the answer. Rather than enabling you
to derive the answer from clues hidden inside the question itself, the questions challenge your
understanding and recall of the subject.

Questions from the "Do I Know This Already?" quiz from the beginning of the chapter are
repeated here to ensure that you have mastered the chapter's topic areas. Hopefully, these
questions will help you limit the number of exam questions on which you narrow your choices
to two options and then guess.

The answers to these questions can be found in Appendix A, on page 397.

List the two most common implementations of ISDN.

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List the number of bearer channels for BRI, T1 PRI and E1 PRI.

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What type of information is carried over the D channel?

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List the specifications that define Layer 2 and Layer 3 of ISDN.

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When is it necessary to use dialer in-band in an ISDN BRI configuration?

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