VDV Voice Systems 4

Question 1

Which protocol does SIP use for transporting voice media (audio packets) between endpoints?

Accepted Answer

RTP over UDP

Answer

SIP uses RTP (Real-Time Protocol) carried over UDP to transport the actual voice media between endpoints due to UDP's low latency characteristics.

Question 2

What is the acceptable maximum one-way voice delay recommended by ITU-T G.114 for toll-quality calls?

Accepted Answer

150 ms

Answer

ITU-T G.114 recommends a maximum one-way delay of 150 ms for toll-quality voice to prevent noticeable conversational degradation.

Question 3

A technician measures 24 VDC on a tip and ring pair at a 66-block. What does this indicate?

Accepted Answer

The line is on-hook and active

Answer

A standard on-hook analog POTS line carries approximately 48 VDC (–48V); reading 24 VDC suggests the line is active but at half battery, which may indicate a high-resistance fault.

Question 4

What is the purpose of a Music on Hold (MOH) server in a PBX system?

Accepted Answer

Stream audio to callers placed on hold

Answer

An MOH server streams audio content — music, announcements, or promotional messages — to callers who have been placed on hold.

Question 5

Which feature in a VoIP system allows an extension to be answered from a different phone without transferring?

Accepted Answer

Call pickup

Answer

Call pickup allows a user at one extension to answer a call ringing at a different extension by dialing a pickup code.

(VDV) Voice Data Video Technician Certified Practice Test

(VDV) Voice Data Video Technician Certified Practice Test

VDV Voice Systems 4