1. Which of the following are the major VoIP protocols?
Answers:
• SIP
• H.323
• SMTP
• MGCP
• FTP
• RTP
• RTCP
2. What are the three main steps required in the analog-to-digital conversion process?
Answers:
• Compression
• Encoding
• Filtering
• Recording
• Sampling
• Quantization
3. What are the three elements of a security policy necessary for a VoIP network?
Answers:
• Transport Security
• Data Security
• Network Security
• Intrusion Detection
4. Which of the following are types of address signaling?
Answers:
• TDM
• Pulse dialing
• DTMF
• FDM
5. Which of the following signaling protocols can be used with gateways over a VoIP network?
Answers:
• SIP
• H.264
• H.323
• MGCP
6. Which of the following provide transport security by using encryption, data integrity and data authentication?
Answers:
• VPNs
• Firewalls
• Antivirus
• IPSec
7. Which of the following protocols are assigned ports for each voice call?
Answers:
• RTP in transmit direction
• RTCP in transmit direction
• RTP in receive direction
• RTCP in receive direction
8. Through which protocols can VPNs be implemented at layer 2?
Answers:
• NTP
• PPTP
• RTCP
• L2TP
9. Which of the following are the major framing standards used for Channel Associated Signaling (CAS) by T1?
Answers:
• Super Frame (SF)
• Multi Frame (MF)
• Super Extended Frame (SEF)
• Extended Super Frame (ESF)
10. Which of the following services are provided by Real-time Transfer Protocol(RTP)?
Answers:
• Time stamping
• Acknowledgements
• Sequence numbering
• Delivery monitoring
11. Which of the following are voice compression techniques?
Answers:
• Waveform algorithms
• Frequency algorithms
• Source algorithms
• Encoding algorithms
12. Which of the following is used by an exchange to convert analog audio to digitized audio?
Answers:
• SS7
• PCM
• ISDN
• DSL
13. Which of the following signaling protocols is based on the ISDN Q.931 standard?
Answers:
• Q.933A
• DPNSS
• QSIG
• SS7
14. How many voice conversations are possible on an E1 line simultaneously?
Answers:
• 16
• 24
• 30
• 32
15. What is the full form of 3DES?
Answers:
• Triple Decoding Encoding Standard
• Triple Data Encryption Standard
• Triple Data Encoding Standard
• Triple Digital Encryption Service
16. According to the OSI model, which layer performs the function of transforming bits of data into electrical signals and sending those signals across the media?
Answers:
• Network
• Data Link
• Transport
• Physical
17. What is the full form of BGP?
Answers:
• Border Gateway Protocol
• Border Gateway Police
• Border Global Position
• Border Global Protocol
18. How many bits are there in a Class B address in Net ID (Network portion) and Host ID (Host Portion) fields by default?
Answers:
• Net ID=8 bits & Host ID=24 bits
• Net ID=16 bits & Host ID=16 bits
• Net ID=24 bits & Host ID=8 bits
• None of the above
19. What is the full form of POTS?
Answers:
• Public Old Telephone Service
• Plain Old Telephone Service
• Plain Old Telecommunication System
• Protocols Of Telecommunication System
20. What is the full form of L2TP?
Answers:
• Level 2 Technology Protocol
• Level 2 Transmission Protocol
• Layer 2 Transport Protocol
• Layer 2 Tunneling Protocol
21. Which of the following is responsible for electrical echo on telephone networks?
Answers:
• Speakerphones
• Impedance mismatch
• Incorrect voltage
• All of the above
22. State whether true or false:
Stateful firewalls do not remember the previous traffic that has occurred earlier in the session
Answers:
• True
• False
23. What are the functions of Call Control?
Answers:
• Call setup
• Call maintenance
• Call termination
• All of the above
24. Which of the following is the most common trunk signal type used by E&M signaling?
Answers:
• Wink-start
• Immediate-start
• Delay-start
• Loop-start
25. What is the range of the frequency of a telephone channel?
Answers:
• 10 Hz to 9000 Hz
• 300 Hz to 3400 Hz
• 200 Hz to 20000 Hz
• 16 Hz to 1600 Hz
26. What is the full form of CCS?
Answers:
• Conditional Channel Signaling
• Combined Channel Signaling
• Common Channel Signaling
• Collective Channel Signaling
27. Which of the following is one of the most important things common in all IP phones?
Answers:
• Global Positioning System (GPS)
• Bluetooth
• Network Interface Card (NIC)
• None of the above
28. What do you call a medium which allows multiple channels?
Answers:
• Multi mode
• Single mode
• Broadband
• Baseband
29. Which of the following methods is most commonly used to remove echo in telephone networks these days?
Answers:
• Echo Avoidance
• Echo Suppression
• Echo Cancellation
• All of the above
30. What is the minimum bandwidth required for VoIP to deliver high quality services?
Answers:
• 32 kbps
• 64 kbps
• 128 kbps
• 256 kbps
31. According to the ITU standard G.114, what is the maximum delay acceptable for high quality voice?
Answers:
• 100 ms
• 125 ms
• 150 ms
• 200 ms
32. Which of the following classes are used for host addressing?
Answers:
• Class A
• Class B
• Class C
• Class D
• Class E
• All of the above
33. What is the function of D (Data) channel in ISDN?
Answers:
• It is used for carrying data
• It is used for carrying voice
• It is used for carrying signaling information
• All of the above
34. Which TCP port number is used by H.323 protocol for call setup?
Answers:
• 5060
• 1720
• 1718
• 2727
35. What is the path of wires that connect the subscriber's telephone to the telephone company's switch located at the latter's central office known as?
Answers:
• Trunk
• Local Loop
• Demarcation Point
• Point of Presence
36. Which of the following can be used to hide internal network addresses and allow several computers on LAN to simultaneously share the router's global IP address?
Answers:
• DHCP
• Firewall
• NAT
• None of the above
37. Which of the following VoIP protocols define end-to-end call signaling methods?
Answers:
• SIP
• MGCP
• RTP
• H.323
38. Which of the following is the reason for using UDP instead of TCP for voice transmission?
Answers:
• UDP is more reliable as compared to TCP
• UDP is fast as compared to TCP
• UDP re-transmits any packet lost during transmission whereas TCP does not
• All of the above
39. Which of the following has the correct sequence (from the lowest layer to the highest)?
Answers:
• Physical, Network, Data Link, Session, Transport, Presentation, Application
• Physical, Data Link, Network, Transport, Session, Presentation, Application
• Transport, Session, Data Link, Application, Presentation, Network, Physical
• Physical, Data Link, Network, Transport, Presentation, Session, Application
40. What is the full form of DSL?
Answers:
• Digital Subscription Line
• Digital Super Link
• Digital Speed Line
• Digital Subscriber Line
41. State whether true or false:
QSIG is implemented on PRI interfaces only.
Answers:
• True
• False
42. Which of the following protocols is used in a VoIP call at the application layer of the TCP/IP model?
Answers:
• NTP
• RTCP
• RTP
• All of the above
43. For which of the following services is SS7 responsible?
Answers:
• Basic call setup, management and tearing down of connections
• Call forwarding
• Calling party number display
• All of the above
44. State whether true or false
VoIP runs only on the internet. It cannot run on any other network.
Answers:
• True
• False
45. Which of the following are examples of CCS?
Answers:
• QSIG
• Q.933A
• SS7
• DPNSS
• All of the above
46. Which of the following devices is used to physically connect all network devices like PCs, IP phones etc. to the LAN?
Answers:
• Router
• Switch
• Firewall
• Server
47. Which of the following are ITU standards for voice compression?
Answers:
• G.701
• G.711
• G.726
• G.728
• G.729
• G.729A
• All of the above
48. What is a soft phone?
Answers:
• It is a hardware phone especially made for VoIP
• It is a software that works on a laptop, desktop or a pocket PC
• It is the traditional phone that we use these days
• None of the above
49. On which of the following IP enabled devices can VoIP telephone services work?
Answers:
• Computer
• Personal Digital Assistant (PDA)
• IP telephone
• All of the above
50. What is the full form of DPNSS?
Answers:
• Dedicated Private Network Signaling Services
• Digital Public Network Signaling System
• Dual Primary Network System Signaling
• Digital Private Network Signaling System
