Chapter Review

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1. An external modem is a small box that is connected to the computer by a ______________ cable running from the computer's port to the modem's computer-cable connection.
2. The modem at the _______________ end converts digital signals into analog signals.
3. Baud rate refers to the speed of oscillation of the _____________ _____________ on which a bit of data is carried.
4. The bps can be greater than the __________ rate.
5. Asynchronous transmission occurs over __________________ __________.
6. The Microcom Network Protocol (MNP) is a standard for asynchronous __________ - _____________ control.
7. In asynchronous communication, it is possible to double throughput by using ____________________ without having to pay for a faster channel speed.
8. Synchronous communication relies on a _____________ scheme coordinated between two devices.
9. More advanced, complex repeaters can act as multiport _________ to connect different types of media.
10. Repeaters do not have a __________________ function and so will pass along all data from one segment to the next.
11. A repeater takes a weak signal and ______________________ it.
12. A repeater functions at the ________________ layer of the OSI reference model.
13. If the volume of traffic from one or two computers or a single department is flooding the network with data and slowing down the entire operation, a ________________ could isolate those computers or that department.
14. The bridge builds a routing table based on the ________________ addresses of computers that have sent traffic through the bridge.
15. Bridges work at the OSI __________ - _________ layer and, specifically, the _____________ ______________ ________________ sublayer.
16. Bridges are often used in large networks that have widely dispersed segments joined by __________________ ___________.
17. Under spanning tree algorithm (STA), software can sense the existence of more than one _____________, determine which would be the most efficient, and then configure the bridge to use that one.
18. Bridges connect two segments and regenerate the signal at the ______________ level.
19. Routers work at the _________________ layer of the OSI reference model.
20. Because they must perform complex functions on each packet, routers are _________________ than most bridges.
21. Routers do not look at the destination node address; they look only at the _________________ address.
22. Unlike bridges, routers can accommodate multiple active ____________ between LAN segments and choose among them.
23. The two major types of routers are ____________ and __________________.
24. A brouter will ______________ nonroutable protocols.
25. Most often, gateways are dedicated ________________ on a network.
26. The gateway takes the data from one environment, strips it, and repackages it in the __________________ ___________ from the destination system.
27. Gateways are ___________ specific, which means that they are dedicated to a particular type of transfer.
28. With the exception of ADSL, public telephone lines require users to _______________ make a connection for each communication session.
29. The three factors an administrator must take into account when considering how best to implement communication between two modems are __________________, _______________, and __________.
30. Leased lines provide ___________________ connections that do not use a series of switches to complete the connection.
31. A good remote-access option that offers stable lines for companies that are constantly communicating between networks is to use ______________ lines.
32. The ____________ - _____ - _____________ _____________________ ___________________ allows a remote client to establish a secure connection to the corporate LAN over the Internet and RAS.
33. Because the PSTN was designed primarily for voice, _________ - _____ lines do not have the consistent quality required for secure data communications.
34. A dedicated line is _______________ and more _______________ than a dial-up connection.
35. One advantage that dedicated lines offer over dial-up lines is that the service company implements ____________ _______________________ to improve communication, thereby ensuring line quality.
36. Digital lines provide ______________ - ___ - _____________ synchronous communication.
37. Because DDS uses ________________ communication, it does not require modems.
38. T1 uses a technology called ____________________ in which several signals from different sources are collected into a component and fed into one cable for transmission.
39. T1 can accommodate 24 ____________________ data transmissions over each two-wire pair.
40. Subscribers who do not need or cannot afford the bandwidth of an entire T1 line can subscribe to one or more T1 _________________.
41. With packet switching, the data is broken down into packets, and each packet is tagged with a _____________________ _________________ and other information.
42. At the destination, the packets are _____________________ into the original message.
43. Two packets from the original data package can arrive out of sequence because they followed different ____________ to reach the same destination.
44. Virtual circuits are composed of a series of ________________ connections between the sending computer and the receiving computer.
45. Because of its extensive ____________ _______________, X.25 can appear to be slow.
46. X.25 was originally developed for the __________________ environment.
47. Frame-relay data travels from a network over a ________________ _________________ line to a data switch and into the frame-relay network.
48. Frame-relay networks can also provide subscribers with __________________ as needed, which lets the customer make nearly any type of transmission.
49. Frame-relay networks are faster at performing basic ________________ - __________________ operations than are X.25 networks.
50. ATM is an advanced implementation of ______________ ______________ that provides high-speed data transmission rates.
51. ATM transmits data in 53-byte _________ rather than variable-length frames.
52. ATM switches are multiport devices that can act as either ____________ to forward data from one computer to another within a network or _________________ to forward data at high speeds to remote networks.
53. ATM uses switches as ___________________________ to permit several computers to put data on a network simultaneously.
54. ATM can be used with existing _____________ designed for other communications systems.
55. Basic Rate ISDN divides its available ________________ into three data channels.
56. FDDI is a specification that describes a high-speed (100 Mbps) token-ring LAN that uses ___________ - __________ media.
57. FDDI can be used for __________________ networks to which other, low-capacity LANs can connect.
58. A computer on an FDDI network can transmit as many frames as it can produce within a predetermined time before letting the ____________ go.
59. Traffic in an FDDI network consists of two similar streams flowing in opposite directions around two counter-rotating ______________.
60. An advantage of the dual-ring topology is ______________________.
61. To isolate serious failures in the ring, FDDI uses a system called _________________ in which a computer that detects a fault sends a signal onto the network.

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