tailieunhanh - CompTIA Network+ Certification Study Guide part 40

CompTIA’s Network+ certification Study Guide part 40 is a globally-recognized, vendor neutral exam that has helped over 235,000 IT professionals reach further and higher in their careers. The 2009 Network+ exam (N10-004) is a major update with more focus on security and wireless aspects of networking. Our new study guide has been updated accordingly with focus on network, systems, and WAN security and complete coverage of today’s wireless networking standards. | 376 CHAPTER 8 Wide Area Networking Q What is the biggest difference between packet-switched and circuit-switched networks A The biggest difference between packet-switched and circuit-switched networks is that circuit switching requires someone to configure and set up each individual connection before it is used where as packet switching allows for dynamic setup and an always-on connection. Q Why is packet-switching technology so much more desirable A Packet switching is more desirable than circuit switching because packet switching divides the transmitting data into packets and given sequence numbers so that they can all be put back together again in the right order at the destination. The benefit of this is that each packet can take a different route to get to its destination. Once there the message will be recompiled and take its original form. Circuit switching does not allow for this kind of flexibility because it is not an always-on switching method. Q Should I memorize the speeds of WAN protocols for the test A Understanding the different kinds of WAN protocols and properties how they differ and why is vital to answering the CompTIA Network exam question correctly. There will be plenty of questions on the exam that are scenario-based in which you have to know the speeds of various WAN protocols and properties. Q Is Frame Relay more flexible compared to FDDI A Frame Relay is more flexible than FDDI because if an organization needs to communicate to their remote sites they can add or take away channels as needed depending on how much bandwidth is required. With FDDI the idea is to provide high-speed service to all stations connected to the ring. If you no longer need such services at one remote site you cannot change the fixed bandwidth without affecting all sites. Q What kind of organizations use Optical Carrier OCx links A The SONET standard defines a hierarchy of interface rates that allow data streams at different rates to be multiplexed as shown in Table .