CCNA Exam 642-432 - Cisco Voice Over IP

CCNA Exams 642-432 with subject Cisco Voice Over IP to help you preparing CCNA exams.

Exam : 642-432
Title : Cisco Voice Over IP
Ver : 02.13.07

3 Sample Questions out of 213 Questions:

QUESTION 5
What is the E.164 numbering plan?
A. A proprietary PBX number plan.
B. The IETF North American number plan.
C. The European PBX standard telephony number plan.
D. The ITU worldwide number plan.

Answer: D

Explanation:
Numbering Scheme
The standard PSTN is a large, circuit-switched network. It uses a specific numbering scheme, which complies with the ITU-T international public telecommunications numbering plan (E.164) recommendations. For example, in North America, the North American Numbering Plan (NANP) is used, which consists of an area code, an office code, and a station code. Area codes are assigned geographically, office codes are assigned to specific switches, and station codes identify a specific port on that switch.

The format in North America is 1Nxx-Nxx-xxxx, with N = digits 2 through 9 and x = digits 0 through 9. Internationally, each country is assigned a one- to three-digit country code; the country’s dialing plan follows the country code. In Cisco’s voice implementations, numbering schemes are configured using the destination-pattern command.

E.164 is an ITU-T recommendation which defines the international public telecommunication numbering plan used in the PSTN and some other data networks.

QUESTION 7
Which of the following best describes the main difference between G.729 and G.729a?
A. G.729 has higher complexity.
B. G.729 requires a higher bit rate.
C. G.729a has built-in echo cancellation.
D. G.729a has improved speech performance.
E. G.729a is designed for use with 3DES encryption

Answer: A

QUESTION 8
What type of signalling is used for a circuit transmitted within the same channel as the voice?
A. PCM
B. SS7 Signalling
C. In-line Signalling
D. Common Channel Signalling
E. Channel Associated Signalling

Answer: E