VoIP - Voice Over IP MCQ Questions Answers

1. Maximum number of telephone calls that can be made from an ISDN PRI (for T1) simultaneously?

2. Which factors can affect QoS (Quality of Service) on a VoIP call?

3. What is the speed of a T1 line?

4. Which ones are voice compression techniques?

5. Is it possible for a POTS line running broadband DSL service to support VoIP telephony in the home?

6. Which can correct small amounts of packet loss in VoIP network?

7. Which protocol does VoIP use at the transport layer of the TCP/IP model?

8. On which layer of the OSI model does TCP & UDP work?

9. Two steps involved in the process of conversion of digital signals into analog signals?

10. Which cable is mostly used in traditional telephones?

11. Protocol to reduce the size of RTP/UDP/IP headers from 40 bytes to 2 bytes (mostly) to save bandwidth and provide better throughput?

12. Which services are provided by Real-time Transfer Protocol(RTP)?

13. Which modes of delivery are supported by IPsec?

14. Into how many smaller bandwidth channels can a T1 line be subdivided?

15. Which encryption technology cannot be used on international networks?

16. Major framing standards used for Channel Associated Signaling (CAS) by T1?

17. Telephony signaling protocol suite used to set up most of the world's PSTN calls?

18. QoS technique to define the maximum size of data packets to prevent excessive serialization delays?

19. Between Asymmetric and Symmetric transmissions, which statement is true of Symmetric transmission?

20. Which signaling protocol is used in a common channel to signal all other channels in ISDN?

21. RTP (Real-time Transport Protocol) requests retransmission if a voice packet is lost.

22. Functions of a voice gateway?

23. Three elements of a security policy necessary for a VoIP network?

24. You have to use an H.323 proxy if the firewall does not support dynamic access control.

25. How many bits are there in a MAC address?

26. Which VoIP protocol is an emerging standard for PSTN gateway control?

27. On which IP enabled device can VoIP telephone services work?

28. Which QoS technique can be used to ensure consistent delivery and throughput of voice packets?

29. Three main steps required in the analog-to-digital conversion process?

30. Which are ITU standards for voice compression?

31. Which device is used to physically connect all network devices like PCs, IP phones etc. to the LAN?

32. Which are examples of CCS?

33. VoIP runs only on the internet. It cannot run on any other network.

34. Through which protocols can VPNs be implemented at layer 2?

35. For which service is SS7 responsible?

36. Which are true regarding circuit-switched networks (POTS) and packet-switched networks?

37. Which protocol is used in a VoIP call at the application layer of the TCP/IP model?

38. QSIG is implemented on PRI interfaces only.

39. Which one has the correct sequence (from the lowest layer to the highest)?

40. Reason for using UDP instead of TCP for voice transmission?

41. Which VoIP protocols define end-to-end call signaling methods?

42. How to hide internal network addresses and allow several computers on LAN to simultaneously share the router's global IP address?

43. Path of wires that connect the subscriber's telephone to the telephone company's switch located at the latter's central office known as?

44. Which classes are used for host addressing?

45. Which protocols are assigned ports for each voice call?

46. According to the ITU standard G.114, what is the maximum delay acceptable for high quality voice?

47. Which statements regarding CRTP is/are false?

48. Minimum bandwidth required for VoIP to deliver high quality services?

49. Which method is most commonly used to remove echo in telephone networks these days?

50. What do you call a medium which allows multiple channels?

51. Which are the major VoIP protocols?

52. One of the most important things common in all IP phones?

53. Components of local loop signaling?

54. Range of the frequency of a telephone channel?

55. Most common trunk signal type used by E&M signaling?

56. Stateful firewalls do not remember the previous traffic that has occurred earlier in the session

57. Which one provide transport security by using encryption, data integrity and data authentication?

58. Which one is responsible for electrical echo on telephone networks?

59. Which signaling protocol can be used with gateways over a VoIP network?

60. Types of address signaling?

61. Which layer of the TCP/IP model ensures the quality and deliverability of VoIP packets?

62. How many bits are there in a Class B address in Net ID (Network portion) and Host ID (Host Portion) fields by default?

63. 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?

64. How many voice conversations are possible on an E1 line simultaneously?

65. Which ITU standard delivers faxed documents as e-mail attachments over a VoIP netwok?

66. Which signaling protocol is based on the ISDN Q.931 standard?

67. Which one is used by an exchange to convert analog audio to digitized audio?

68. Length of IP v4 addresses (in bits)?

69. Full form of PSTN?

70. Which protocol provides end-to-end delivery services for data that requires real-time support such as interactive voice and video?

71. Full form of TDM?

72. Full form of SS7?

73. Is it possible to transport fax and modem traffic over a VoIP network?

74. Full form of DPNSS?

75. What is a soft phone?

76. Full form of DSL?

77. Which TCP port number is used by H.323 protocol for call setup?

78. Function of D (Data) channel in ISDN?

79. Full form of CCS?

80. Functions of Call Control?

81. Full form of L2TP?

82. Full form of POTS?

83. Full form of BGP?

84. Full form of 3DES?