| Question 1 | What is the default encapsulation method on a Cisco router serial interface? A. PPP B. SDLC C. HDLC D. Frame Relay
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| A1: | Answer C is correct; on serial interfaces, Cisco routers use the Cisco version of HDLC as their default encapsulation type. Answer A is incorrect; to enable PPP encapsulation on a serial interface, issue the encapsulation ppp command in interface configuration mode. Answer B is incorrect; if the router supports it (and not all Cisco routers do), the command to enable SDLC on a serial interface is encapsulation sdlc in interface config mode. Answer D is incorrect; to enable Frame Relay, from interface config mode, type encapsulation frame-relay. |
| Question 2 | Which of the following would provide connectivity between a branch office and the central site, assuming that the branch office supports a group of salespeople who need regular access to email and file servers at the central site at no more than 256Kbps? A. Dedicated B. ISDN C. Asynchronous modem D. Frame Relay
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| A2: | Answers B and D are correct. ISDN supports up to 128Kbps and is considered the slowest connection that is usable between branch and central sites. Frame Relay is the standard primary connection from most branches to the central site. Answer A is incorrect; a dedicated connection is probably overkill in this scenario. Answer C is incorrect; an asynchronous modem would be too slow to support multiple concurrent users connecting to remote servers. |
| Question 3 | Which of the following can be considered either branch-office or central-site equipment? A. 1700 Series router B. 2600 Series router C. 3600 Series router D. 7200 Series router
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| A3: | Answer B is correct; the 2600 Series router is considered the highest you would use at a branch office and the slowest router for a central site. Answer A is incorrect; the 1700 is considered too slow and does not provide sufficient scalability for the central site. Answer C is incorrect; the 3600 Series router is a central-site router and considered overkill for a branch office. Answer D is incorrect; the 7200 Series router is a high-end router suitable for incredibly high speeds. A branch office would never fully utilize the 7200. |
| Question 4 | Which of the following would be considered a backup connection for a SOHO? A. Dedicated connection B. Frame Relay C. DSL D. Asynchronous modem
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| A4: | Answer D is correct; a SOHO typically requires no more than DSL, cable, or ISDN as its primary connection. The asynchronous modem is slower than any of these primary connections and is suitable for backup. Answer A is incorrect; a dedicated connection would be a primary connection if used at all in a SOHO environment. Answer B is incorrect; like a dedicated connection, if Frame Relay were used, it would be the primary connection at a SOHO. Answer C is incorrect; DSL is usually considered a primary connection and would therefore not be a secondary or backup connection. |
| Question 5 | Assuming all the following technologies are available, which of the following would be the best choice for a telecommuter who uploads a large amount of data once a day? A. ISDN/PRI B. ISDN/BRI C. Frame Relay D. Asynchronous modem
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| A5: | Answer B is correct; telecommuters are typically in the SOHO environment. ISDN, like an asynchronous modem, is a dial-on-demand connection but has greater bandwidth potential. BRI is much less expensive than PRI. Answer A is incorrect; and ISDN/PRI would be the equivalent of a T1, which is overkill for a SOHO. Answer C is incorrect; like an ISDN/PRI, Frame Relay would be overkill at a SOHO. Answer D is incorrect; a large amount of data would take too long over an asynchronous modem connection. |
| Question 6 | Which of the following would be a dial-on-demand technology? A. Dedicated connection B. ISDN C. ATM D. Frame Relay
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| A6: | Answer B is correct; ISDN can be "dialed up" as needed. Answer A is incorrect; a dedicated connection is already established and therefore not brought up "on-demand." Answer C is incorrect; like a dedicated connection, ATM is already connected all the time. Answer D is incorrect; most service providers do not allow for switched virtual circuits (SVCs). As such, Frame Relay connections are always connected. |
| Question 7 | Why are broadband connections not used more frequently as a WAN connection mechanism? A. Cost B. Reliability C. Availability D. Difficult to manage
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| A7: | Answer C is correct; the main reason broadband connections are not more frequently utilized is that their availability is much lower in comparison to other, older technologies. Answer A is incorrect; for the most part, broadband connections are cheaper than their nonbroadband counterparts. Answer B is incorrect; the reliability of broadband connections is nearing the reliability of the other WAN technologies. Answer D is incorrect; broadband connections are easy to set up and manage. |
| Question 8 | Which of the following would help you decide to use a leased line as opposed to a Frame Relay circuit? (Choose all that apply.) A. Short connect times B. Long connect times C. Short distances D. Long distances
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| A8: | Answers B and C are correct; if you will be connecting for long periods of time over short distances, it can be cost-effective, in some circumstances, to have a leased, dedicated line. The leased, dedicated line ensures that you will not be sharing the bandwidth with any other entity. Answer A is incorrect; short connect times typically don't warrant a dedicated connection. Answer D is incorrect; long distances are usually cost-prohibitive when considering a leased, dedicated line. |
| Question 9 | Which of the following are circuit-switched connections? (Choose all that apply.) A. ISDN B. Frame Relay C. DSL D. Asynchronous modem
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| A9: | Answers A and D are correct. ISDN uses the same underlying framework as a typical modem. The key to a circuit-switched connection is that once the connection is established, you must break the connection and reconnect to get a different and better signal. Asynchronous modems use the PSTN to make and receive calls. The PSTN is based, even if only in theory in newer environments, on individual electronic circuits opening and closing for the duration of a call, from point A to point B. Answer B is incorrect; Frame Relay is a packet-switched technology. Answer C is incorrect; DSL is an ATM technology that uses cell switching, not circuit switching. Cell switching is similar in concept to packet switching. |
| Question 10 | Which of the following would allow you to accept ISDN/BRI calls at the central site? (Choose all that apply.) A. Frame Relay B. ISDN/PRI C. Asynchronous modem D. ISDN/BRI
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| A10: | Answers B and D are correct. An ISDN/PRI can accept connections from as many as 23 BRI clients if each client uses only 1 B channel. The minimum requirement to accept a BRI phone call would be a BRI. Answer A is incorrect; Frame Relay circuits cannot, natively, accept a BRI phone call. Answer C is incorrect; an asynchronous modem cannot accept an ISDN/BRI connection. |
