1. IT-320Chapter 17 Voice Communications

2. Objectives 1. Explain how DS-0 relates to a voice communication channel. 2. Describe the hierarchy used with the PSTN. 3. Describe the function of SS7. 4. Define PBX and Centrex, listing the advantage and disadvantage of each. 5. Compare and contrast PSTN and VoIP. 6. List and describe the three main protocols used for VoIP. 7. List and describe the characteristics of the various electromagnetic waves used in wireless communications. 8. Compare and contrast the various 802.11 standards. 9. Compare and contrast Bluetooth and the 802.11 standard.

3. Objectives

4. FIGURE 17-1 The Hierarchy of Switching Systems Used on the PSTN Patrick Regan Wide Area Networks Copyright ©2004 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.

5. FIGURE 17-2 Enterprise IP Telephony Gateway Configuration Patrick Regan Wide Area Networks Copyright ©2004 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.

6. FIGURE 17-3 The H.323 Protocol Suite Patrick Regan Wide Area Networks Copyright ©2004 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.

7. FIGURE 17-4 The H.323 Network Patrick Regan Wide Area Networks Copyright ©2004 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.

8. IT-320 Chapter 18 Wireless Technology Used in WANs

9. FIGURE 18-1 A Wireless End Station and a Wireless Access Point Patrick Regan Wide Area Networks Copyright ©2004 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.

10. FIGURE 18-2 The Hidden Node Problem Patrick Regan Wide Area Networks Copyright ©2004 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.

11. FIGURE 18-3 The 4-way Handshake Patrick Regan Wide Area Networks Copyright ©2004 by Pearson Education, Inc. Upper Saddle River, New Jersey 07458 All rights reserved.