Chapter ! 1. Which part of an asynchronous data stream is used for bit synchronization between transmitter and receiver? a. START BIT d. first data bit b. PARITY BIT e. none of the above c. STOP BIT ANSWER: A 2. Which circuit is used to assist in clock recovery for synchronous data transmissions? a. balanced modulator d. hybrid transfer b. phase shifter e. none of the above c. scrambler ANSWER: E 3. An 8-PSK system has an incoming data stream at 2400 bps. What is the symbol rate of the transmitter? a. 2400 sps d. 600 sps b. 1200 sps e. none of the above c. 800 sps ANSWER: C 4. Which RS232C signal is considered to be a remote handshake between two stations? a. RTS - request to send d. DSR - data set ready b. CTS - clear to send e. none of the above c. CD - carrier detect ANSWER: C 5. Which type of error is associated with a bad stop bit? a. parity d. receive register full b. overrun e. none of the above c. framing ANSWER: C 6. The purpose of RS232C is to a. convert digital data to analog data. b. convert serial to parallel data. c. establish a standard interface between terminals and modems. d. establish an interface between local and long distance lines. e. none of the above ANSWER: C 7. In a multipoint network, which station is the communications controlling station? a. primary d. web master b. secondary e. none of these c. supervisory ANSWER: A 8. Communication simultaneously, in both directions, between two stations is know as a. simplex d. duplex apartment b. half duplex e. a mistake c. full duplex ANSWER: C 9. a. b. of these c. An example of a medium is coax cable d. none of these fiber optic cable e. all radio waves (air)

a. modem b. UART (universal asynchronous transmitter/receiver) c. communications controller d. terminal e. none of these is DCE ANSWER: A Chapter 2 1. What is the bandwidth of the telephone system? a. 300 - 3KHz d. 600 - 25KHz b. 500 - 5KHz e. 150 - 3500KHz c. 1KHz - 20KHz ANSWER: A 2. Which of these is specified by Cconditioning? a. signal to noise ratio d. gain/attenuation distortion b. harmonic distortion e. standing wave ratio c. phase hits ANSWER: D 3. Long distance trunk lines operate as _______ lines. a. simplex c. full duplex b. half duplex ANSWER: B 4. Pulse spreading is a result of a. relative delay distortion d. phase impulse hits b. amplitude jitter e. crosstalk c. phase jitter ANSWER: A 5. Which measurement compares signal strength to noise level? a. attenuation/gain distortion d. impulse hits b. signal to noise ratio e. amplitude jitter c. standing wave ratio ANSWER: A 6. Which telephone line impairment is a change in signal amplitude for a short time duration? a. white noise d. interference b. gain hit e. signal to noise ratio c. harmonic distortion ANSWER: B 7. Line conditioning is performed on a. dial up lines d. answers a, b, and c b. leased lines e. answers b and c c. private lines ANSWER: E 8. Envelope delay distortions a measure of a. amplitude variations across the bandwidth b. phase variations in signals across the bandwidth c. relative time delay across the bandwidth d. signal attenuation across the bandwidth e. how badly the post office mangles your envelopes ANSWER: C 9. D-conditioning defines specifications of

a.

amplitude variations d. interference limits b. propagation delay variations e. answers c and d c. signal to noise ratio ANSWER: C 10. What is done to a telephone line to tighten gain/attenuation parameters? a. it is replaced with new copper lines d. it is switched to a different line b. it is replaced with fiber cable e. nothing c. it is conditioned ANSWER: C

Chapter 3 1. CRC-31 error detection method uses more overhead than parity. ANSWER: F 2. Checksum characters are created by adding all the bytes of a message and discarding carries. ANSWER: T

3. What is the limitation for parity as an error detection method? a. only reliable if a single error occurs in a character b. a bad parity bit does not guarantee that there is something wrong in the character received c. different parity errors occur if you are using an even or odd parity system d. none of these apply ANSWER: A

4. What TELCO parameter limits the type of modem that can be used with a given data rate? a. bandwidth c. attenuation b. noise d. line impedance ANSWER: A

5. Which of the following error methods is used for error correction? a. LRC c. Checksum b. CRC d. Parity ANSWER: A

6. How many bit errors within a single transmission can be corrected by using the Hamming code for error correction? a. 1 c. 1 per character b. 2 d. as many errors as are present ANSWER: A

ANSWER: E 10. Which of these is considered DCE (data communications equipment)?

7. Using an ODD parity system, what is the state of the parity bit for a C character? ASCII for C is 43. a. high b. low

ANSWER:

B

ANSWER:

A ANSWER: C

8. To correct a character with a bad parity bit, the receiver will a. invert the parity bit b. invert the bit that is bad c. ignore the bad character d. request that the bad character (and possibly, the rest of the message) be retransmitted ANSWER: D

8. In which OSI model level would be found specifications for virtual routing throughout a network? a. data link c. session b. network d. application ANSWER: B

7. An 8-PSK system has an incoming data stream at 2400 bps. What is the symbol rate of the transmitter? a. 2400 sps c. 800 sps b. 1200 sps d. 600 sps ANSWER: C

9. Which error detection method uses a quasi-"division" algorithm to generate the error character? a. parity c. cyclic redundancy check (CRC) b. longitudinal redundancy check (LRC) d. hamming code ANSWER: C

1. All the options below, except one are selected using the ACIA control register. Which one is not an option? a. number of data bits d. odd or even parity b. number of stop bits e. none - all of these are selectable options c. number of start bits ANSWER: C 2. Which of these is NOT indicated in the ACIA status register? a. interrupt request b. receive data register full c. parity error d. clear to send e. none - all of these are indicated in the status register ANSWER: E

8. Which modem is used to handle 9600 bps dat rates? a. QPSK c. FSK b. BPSK d. QAM ANSWER: D

9. How many symbols are produced by a QPSK modem? a. 2 c. 8 b. 4 d. 16 ANSWER: B

10. How many Hamming bits are inserted into a 100 bit message? a. 6 d. 10 b. 7 e. 128 c. 8 ANSWER: B

1. In a bus topology, if one station fail, the entire system is down. ANSWER: F 2. A star or hub topology uses a central station for controlling the interconnection between two other stations. ANSWER: T

10. What TELCO parameter limits the type of modem that can be used with a given data rate? a. bandwidth c. attenuation b. noise d. line impedance ANSWER: A

3. Which of these does NOT have to be the same for ACIAs at both ends of the data connection for successful data transfer? a. same number of data bits b. same data rate c. same number of stop bits d. same type of parity used e. none - all of these have to be the same for successful, error free transfer of data ANSWER: E

1. Frequency division multiplexers send more channels in one transmission than do time division multiplexers. ANSWER: T 2. Time division multiplexing allocates a time slot for each channel inputted to the multiplexer. ANSWER: T

3. Addresses in the data link level of the OSI model are virtual addresses representing destination and source networks. ANSWER: F

4. The applications level of the OSI model is where the user interfaces with the system. ANSWER: T

5. Packet switching is some times referred to as "near real time" switching. ANSWER: T 6. Which topology experiences contention for access to the network? a. bus d. hub b. ring e. Mount Hood c. star ANSWER: D

4. Which of these does NOT generate an Interrupt Request assuming both transmit and receive interrupts are enabled? a. parity error d. cpu failed to read receive data in time b. undetected start bit e. none - all of these generate an interrupt c. transmit register empty ANSWER: B

Which of the following encoding types uses the first half of the bit time to hold the complement of the data and the second half to provide for a clock transition? a. raw data b. non-return to zero mark inverted (NRZ-AMI) c. Manchester d. return to zero mark inverted (RZAMI) e. none of these ANSWER: C

5. Which of these is NOT a function of the ACIA transmit area? a. set data rate d. check for framing bits b. add framing and parity bits e. none - all of these are transmit functions c. convert parallel data to serial ANSWER: D

7. At which OSI level is a standard description of a modem and its specifications found? a. physical d. transport b. data link e. application c. network

6. How many different symbols are available from an 8-PSK transmitter a. 3 c. 8 b. 4 d. 16

4. Time division multiplexing a. divides packets into audio cells to be placed on the telephone lines b. assigns channels to different frequencies in the transmission band width c. assigns time slots to each channel's packet sections d. uses asynchronous data transmission only e. is limited to local area networks only

ANSWER:

C ANSWER: A 4. How many consecutive ones is recognized by SDLC as an abort sequence a. 5 d. greater than 14 b. 6 e. none c. 7 - 14 ANSWER: C

a. b. 2. rate of a. b.

5. How many channels are used to make up a group level channel in frequency division multiplexing? a. 1 d. 8 b. 2 e. 12 c. 4 ANSWER: E

CCITT's X.25 EIA's RS232C IBM's Token Ring IEEE's 802.3

c. d.

Ethernet sends and receives data at a 1500 bps c. 10 Mbps d. B 256 Kbps 2500 Kbps

ANSWER: 6. What is a disadvantage of time division multiplexing (TDM)? a. slower transmission rates more overhead b. small bandwidth e. none of these c. large packet sizes ANSWER: D 6. SDLC is a(n) _______________ data link protocol a. bit oriented, frame format d. character oriented, packet format b. character oriented, block format e. asynchronous, character oriented c. bit oriented, message format ANSWER: A d. 5. How many consecutive HDLC frames can be sent without an acknowledge or response a. 7 d. 127 b. 8 e. 511 c. 64 ANSWER: 7. What is the purpose of using alternate mark inversion and return to zero encoding of data? a. more efficient transmission of analog data b. assist in clock recovery c. faster digital data transmission d. increased line bandwidth e. reduced susceptibility to noise ANSWER: B A

3. How long is an untappable Ethernet segment? a. 1000 M c. 2500 M b. 1500 M d. 10 M ANSWER: A

4. Which data link protocol is the basis for the Ethernet data link protocol a. BISYNC c. HDLC b. asynchronous d. SDLC ANSWER: C

8. Which of these is NOT a currently used method of multiplexing data channels onto a single transmission medium? a. time division multiplexing d. code division multiplexing b. frequency division multiplexing e. encrypted division multiplexing c. wave division multiplexing ANSWER: E

7. To avoid interpreting a 01111110 sequence in the data stream, a zero is stuffed after _____ consecutive ones a. 3 d. 6 b. 4 e. 7 c. 5 ANSWER: C

5. A business housed entirely in a single building would use a ______ type network to interconnect its computers and terminals. a. local area c. metropolitan area b. wide area d. underground ANSWER: A

1. An SDLC information control field is recognized by a. a DC3 character d. a P/F bit in a one state b. a SYN SYN sequence e. a one in the most significant bit c. a zero in the least significant bit ANSWER: C 2. An unnumbered frame reject (FRMR) is used for all these problems except a. prohibited data d. out of sequence Nr/Ns number b. invalid command e. all of these are covered by FRMR field c. error in a data bit ANSWER: C

8. Which type of error detection is used with SDLC/HDLC? a. checksum d. Hamming code b. parity e. none c. CRC ANSWER: A

ANSWER: D Each item has a single match - no duplicate choices a. regenerate signals d. entry point into a network b. connect similar networks e. guide traffic thru networks c. connect dissimilar networks 6. repeater A

9. Which of the following is NOT an enhancement specified in HDLC? a. unlimited address field d. b0 is least significant bit b. larger Nr/Ns numbers e. unlimited data field size c. use any character code ANSWER: D

ANSWER: 7. node

ANSWER: 8. bridge

D

ANSWER: 9. 10. Unnumbered commands in SDLC are transmitted by a. primary only c. either primary or secondary b. secondary only d. no one ANSWER: A gateway

B

ANSWER: 10. router

C

3. In the SDLC address field the address specifies a. secondary station only send and receive stations b. primary station only e. primary and secondary stations c. destination and source stations

ANSWER: 1. cell is a. b. c.

E

d. 1. Which specification standard incorporates the Ethernet standard?

The size of a payload for an ATM 48 bytes long 53 bytes long variable

d. dependent on the upper level protocol transported e. dependent on the network in use ANSWER: A 2. Which of these responsibilities does NOT apply to the ATM cell (data link) level? a. translation of addresses to VCIs and VPIs b. header generation c. segmentation and reassembly d. flow control e. cell multiplexing ANSWER: C

ANSWER:

E

9. ISDN is a. a transport type protocol that uses the plain old telephone system b. a data link protocol that uses HDLC as a basis c. digital interface system d. an integrated services network e. all of the above ANSWER: B

c. dial up access to Internet d. e-mail e. all of these services are provided by TELENET ANSWER: E

6. URL addresses identify all except the following a. ISP server d. e-mail server b. physical location of user e. user's PC c. user's network ANSWER: 7. a. b. B d.

3. Which of these types of data flows is used for highly burstable traffic? a. constant bit rate (CBR) c. available bit rate (ABR) b. variable bit rate (VBR) ANSWER: C

10. Which ISDN block is responsible for converting non-ISDN format? a. Terminal Equipment 1 (TE1) d. Exchange Terminal (ET) b. Network Termination 2(NT2) e. none of these c. Terminal Adaptor (TA) ANSWER: C

c.

The digital URL identifies networks and host nodes busy networks type of protocol used e. faulty servers location of ISP A

4. Which term refers to the process of converting a frame or packet into ATM cells? a. adaption d. reassembly b. convergence e. segmentation c. mapping ANSWER: E

1. Which of these can NOT be used to access the Internet? a. on-line service b. Internet service provider (ISP) c. serial line interface protocol (SLIP) d. actuated line program grid (ALPG) e. all of these are methods for accessing the Internet ANSWER: A 2. What is the purpose of Internet Relay Chat (IRC)? a. interactive "real time" access to other users b. web page browsing c. index of web sites d. video teleconferencing e. e-mail transfers ANSWER: A

ANSWER: 8. a. b. c.

Firewalls are used for preventing access by an outside user d. creating Extranets limiting access to certain URLs e. all of these creating Intranets E

ANSWER:

5. Which ATM adaption layer (AAL) is the simplest and carries bursty LAN data traffic a. AAL-0 d. AAL-4 b. AAL-2 e. AAL-5 c. AAL-3 ANSWER: E

6. What is the composition of a ISDN BRI (basic rate interface)? a. 2 B and 1 D channel d. 30 D and 1 B channel b. 2 D and 1 B channel e. 30 B and 1 D channel c. 23 B and 1 D channel ANSWER: A

9. Which of these is NOT a problem with using symmetric private key cryptography? a. brute force attack can be used to uncover key b. transporting key between users c. decrypting long messages takes too much time d. loss or theft of key nullifies security e. all of these are problems using private keys ANSWER: 10. a. Union b. c. C

3. Which OSI level is the TCP part of TCP/IP closely related to? a. transport d. presentation b. network e. applications c. data link ANSWER: A

Who controls the Internet? government d. International Telecommunications Microsoft e. no one Internet Users Group E

7. Which service is NOT included on an ISDN line? a. video b. voice c. data d. teleconferencing e. all of these can be carried by an ISDN line ANSWER: E

4. What does the acronym TCP/IP stand for? a. traffic communications protocol / information protocol b. top cat protocol / international protocol c. telephone communications policy / internet procedure d. telecommunications police / internet patrol e. transport control protocol / internet protocol ANSWER: E

ANSWER:

1. Fiber optic cables have large bandwidths, but are delicate and easy to break? ANSWER: F 2. What is the basic topology of the FDDI network? a. bus d. ring b. star e. hub c. tree ANSWER: D

8. The U.S. primary rate interface (PRI) data rate is a. 10 Mbps d. 100 Mbps b. 1.544 Mbps e. 2.048 Mbps c. 64 Kbps

5. Which of these services is provided by TELENET? a. file transfer b. remote database access

3. What type of station is connected to both transmission paths of a FDDI network?

a. b. c.

single attached station d. back up station dual attached station e. mid-network station mirrored station B

b. c.

block cell

e.

campus

a. b.

ANSWER:

4. Which of these is NOT an advantage of fiber cables? a. easy to interconnect fiber segments b. has a larger usable bandwidth c. freedom from electromagnetic interference d. rugged e. secure - difficult to tap ANSWER: A

ANSWER: C 2. Which is one method of securing cellular transmissions? a. frequency hopping d. password handshake b. area handoff e. cell identification c. packet coding ANSWER: A

c.

direct connection frequency hopping line of sight room roaming diffuse B

d. e.

ANSWER:

5. What is the term for a switched fibre channel network? a. cell d. packet b. cycle e. frame c. fabric ANSWER: C

3. Microwave transmissions a. are done only at night d. are used by the telephone company only b. are done using fiber optic cables e. none of these c. use line of sight ANSWER: C

9. Which method is utilized by wireless networks to overcome voice priority in channel use? a. frequency hopping d. channel sealing b. direct sequencing e. public key c. code division multiplexing ANSWER: D

10. Which satellite type circles the globe in a "fixed" position orbit above the equator? a. LEO d. Irridium b. MEO e. none of these c. GEO ANSWER: C

6. Which of these is NOT an application for fibre channel? a. backbones d. video conferencing b. imaging e. all of these are fibre channel applications c. multimedia ANSWER: E

4. Geostationary or geosynchronous satellites a. orbit about the equator d. are basically repeaters b. appear fixed in relationship to the Earth e. are all of these c. cover a good portion of the Earth's surface ANSWER: B

MILLER

7. Which of these statements is NOT true for SONET? a. uses frequency division multiplexing (FDM) b. common SONET interface ATM is STS-3c/STM at 155 Mbps c. it is a synchronous optical network d. supports both ATM and BISDN e. all of these are true ANSWER: A

5. A standing wave ratio is a measure of a. power out compared to reflected power back b. power out compared to noise out c. the amount of power received d. power radiated from the surface of a waveguide e. power radiated from the antenna ANSWER: A

8. Which type of media is least susceptible to electrical interference? a. microwaved. fiber optics b. unshielded twisted pair cable e. coax cable c. shielded twisted pair cable ANSWER: D

6. Which of these measures provides security to mobile phone transmissions by varying the transmitted frequency? a. direct sequencing d. multipath fading b. frequency hopping e. frequency division multiplexing c. code division multiplexing ANSWER: B

9. What kind of data is transported using the fibre channel? a. voice c. data b. video d. all of the above ANSWER: D

7. Which of these servies is NOT provided by a smart card? a. user authentication d. message decoding b. home locator registry e. visitor location directory c. billing information ANSWER: D

1. What is the unit designation for the area managed by a single cellular phone central office? a. city d. spot beam

8. Which type of infared connection is used for workstations that are relatively close to each other?