Data Comm Chapter 9

1. Wide area networks share a few characteristics with local area networks.

2. Wide area networks in most cases now carry both data and voice.

3. Many of the same technologies and communications protocols found in local area networks are used to create metropolitan area networks.

4. LANs cover much greater distances than MANs do.

5. Some MAN topologies are based on a ring.

6. Most MANs are supported by Ethernet ring technology.

7. SONET was designed to support multiple streams of voice channels.

8. Local area network Ethernet allows users to set their own data transfer rates.

9. A wide area network would not exist without a sub-network.

10. A wide area network's sub-network, or cloud, may be categorized by the way it transfers information from one end of the sub-network to the other.

11. A virtual circuit breaks a large amount of data into n packets.

12. The path in a circuit-switched network exists only in the software.

13. Broadcast networks are as common as circuit-switched and packet-switched networks.

14. Circuit-switched networks were designed primarily for voice signals.

15. The sub-network of a wide area network is the logical infrastructure and thus consists of nodes and various types of interconnecting media.

16. To provide a reliable service, the network requires that a logical connection be established between the two endpoints.

17. A common example of a connection-oriented network application is DNS.

18. The underlying sub-network of a connectionless application cannot be a circuit-switched network.

19. A wide area network's underlying sub-network consists of multiple nodes, each with multiple possible connections to other nodes within the sub-network.

You can assign many meanings to the weights in a weighted network graph.

21. Most wide area networks use some form of Dijkstra's algorithm to determine a least-cost route through a network.

22. Compared to Dijkstra's least-cost routing algorithm, the flooding technique seems more complex.

23. The major disadvantage of flooding is the large number of copied packets distributed throughout the network.

24. One disadvantage of distributed routing is related to the problems that arise if the routing tables need to be updated.

25. When all the routing information is in one place, it is difficult to make updates to the routing information.

26. The first routing algorithm used within the Internet was called a distance vector routing algorithm.

27. Any network is as strong as its strongest link.

28. Some congestion control methods are based on simple techniques such as the flow control methods.

29. CSMA/CD is the only network technology that successfully supports connection admission control and quality of service.

30. CSMA/CA is the most popular LAN protocol.

1. A ____ area network is typically confined to a single building or a couple floors within one building. a. personal c. Metropolitan b. local d. wide

2. A network that expands beyond a metropolitan area is a ____ area network. a. personal c. Metropolitan b. local d. Wide

3. ____ area networks can cover large geographic distances, including the entire Earth. a. Personal c. Wide b. Local d. Universal

4. MANs are almost exclusively ____ networks, and thus capable of supporting data rates into the tens of millions and hundreds of millions of bits per second. a. fiber-optic c. twisted-paired b. copper-wired d. coaxial-cabled

5. ____ are advertised as networks with very low error rates and extremely high throughput. a. PANs c. GANs b. UANs d. MANs

6. A feature that is fairly common in ____ is the ability of a user to dynamically allocate more bandwidth on demand. a. PANs c. MANs b. LANs d. WANs

7. Almost all MANs are based on one of two basic forms of supporting technology: ____ or Ethernet. a. SONET c. GALNET b. SOHO d. SWNET

8. The SONET network topology is a ____. a. star c. bus b. ring d. star-bus

9. SONET rings typically have a failover time of ____ milliseconds. a. 20 c. 40 b. 30 d. 50

10. A ____ profile describes various characteristics about the connection, such as basic data transfer rates, basic burst rates, excess data transfer rates, and excess burst rates. a. bandwidth c. client b. server d. router

11. A local area network works as a ____ network in that clusters of workstations are connected to a central point (hub or switch) through which workstations can transmit messages to one another. a. star-based c. ring-based b. bus-based d. star-ring-based

12. A wide area network connects its workstations through the use of a ____ design and requires routing to transfer data across the network. a. bus c. Mesh b. star d. ring

13. A network that is connected in a ____ is one in which neighbors are connected only to neighbors. a. star c. Bus b. mesh d. star-bus

14. All wide area networks are collections of at least two basic types of equipment: a station and a ____. a. link c. workstation b. server d. node

15. The type and number of interconnections between nodes and the way network data is passed from node to node are the responsibility of the ____. a. sub-network c. Server b. station d. client

16. The three basic types of subnetworks are ____, packet-switched, and broadcast. a. multicast c. circuit-switched b. protocol-switched d. unicast

17. The ____-switched network is most often found in networks designed to transfer computer data (such as the Internet). a. circuit c. Protocol b. packet d. port

18. To distinguish between a piece of data processed at the data link layer and a piece of data processed at the network layer, the term "____" is used at the data link layer, and the term "packet" is used at the network layer. a. load c. Frame b. product d. payload

19. The two types of packet-switched networks are the datagram and the ____. a. static circuit c. standard circuit b. fixed circuit d. virtual circuit

20. When a node on a wide area network ____ network transmits its data, the data is received by all the other nodes. a. broadcast c. circuit-switched b. packet-switched d. datagram packet-switched

21. ____ and virtual circuit networks require path setup time and cannot dynamically reroute packets should a network problem occur. a. Broadcast c. Circuit-switched b. Wireless d. Datagram

22. A ____ network is the only network that offers a dedicated path. a. packet-switched c. virtual circuit b. broadcast d. circuit-switched

23. A ____ network application provides some guarantee that information traveling through the network will be delivered to the intended receiver in the same order in which it was transmitted. a. connectionless c. virtual circuit b. connection-oriented d. packet-switched

24. A ____ application does not guarantee the delivery of any information or data. a. connectionless c. virtual circuit b. connection-oriented d. packet-switched

25. ____ applications do not negotiate a connection, and the transfer of data is rarely, if ever, acknowledged. a. FTP c. Connection-oriented b. Connectionless d. Reliable service

26. A classic algorithm that calculates a least-cost path through a network is ____ algorithm. a. Dijkstra's maximum-cost c. Turing's longest-path b. Dijkstra's longest-path d. Dijkstra's least-cost

27. A network limit, called the ____, can be placed on how many times any packet is copied. a. hop limit c. time to live b. hop count d. time to hop

28. Each time a packet is copied, a counter associated with the packet increases by one. This counter is called the ____. a. hop limit c. TTL count b. time to live d. hop count

29. ____ is advantageous when a copy of a packet needs to get to all nodes. a. Flooding c. Dijkstra's shortest-path b. Dijkstra's least-cost d. Dijkstra's maximum-cost

30. ____ routing involves storing all the routing information at one central location. a. Distributed c. Remote b. Centralized d. Fixed

31. One of the primary advantages of ____ routing is the fact that no single node is responsible for maintaining all routing information. a. centralized c. Distributed b. focalized d. Local

32. ____ and distributed routing are methods for sending routing information. a. Distributed c. Fixed b. Adaptive d. Centralized

33.When routing tables adapt to network changes, the routing system is called ____. a. fixed c. adaptive b. local d. static

34. With ____ routing, routing tables are created once, typically when the network is installed, and then never updated again. a. Fixed c. changing b. Adaptive d. modifying

35. When a network or a part of a network becomes so saturated with data packets that packet transfer is noticeably impeded, ____ occurs. a. network flowing c. frame control b. packet control d. network congestion

36. When an application is simply observing its own throughput and not relying on any special types of signals coming from the network, this is called ____ congestion control. a. explicit c. forward explicit b. implicit d. backward explicit

37. With ____, when a frame relay router experiences congestion, it sends a congestion signal forward to the destination station, which in turn tells the originating station to slow down the transfer of data. a. forward explicit congestion notification (FECN) b. backward explicit congestion notification (BECN) c. implicit congestion control d. remote congestion control

38. In ____, before one node sends a series of n packets to another node, the sending node inquires in advance whether the receiving node has enough buffer space for the n packets. a. explicit congestion control c. connection admission control b. implicit congestion control d. buffer preallocation

39. ____ avoids congestion by requiring users to negotiate with the network regarding how much traffic they will be sending, or what resources the network must provide to satisfy the user's needs before the user sends any data. a. Explicit congestion control c. Connection admission control b. Implicit congestion control d. Buffer preallocation

40. A ____ is a legally binding, written document, that can include service parameters offered in the service, various types of service/support options, incentives if the service levels are exceeded, and penalties if service levels are not met. a. connection admission control c. software license agreement b. service level agreement d. congestion control