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6
Using ISDN and
DDR Technologies
The CCNP Remote Access Exam requires you to have an in depth understanding of various
WAN technologies. In this chapter the discussion focuses on ISDN. ISDN is not a new
technology by any means. However, it is still widely implemented around the world. Even
with the advent of newer (and faster) broadband technologies, ISDN continues to grow in
the workplace, albeit at a slower rate than what has been seen in the recent past.
There are two specific implementation types discussed in this chapter: BRI and PRI.
Although they are based on the same technologies and use the same protocols, their
implementations are very different. This chapter touches on the background information
necessary to give you a solid understanding of each technology.
How to Best Use This Chapter
By taking the following steps, you can make better use of your study time:
·
Keep your notes and answers for all your work with this book in one place for easy
reference.
·
Take the "Do I Know This Already?" quiz and write down your answers. Studies show
retention is significantly increased through writing down facts and concepts, even if
you never look at the information again.
·
Use the diagram in Figure 6-1 to guide you to the next step.