VDV Network Infrastructure 4

Question 1

What is the function of Spanning Tree Protocol (STP) in a switched network?

Accepted Answer

Prevents Layer 2 switching loops by blocking redundant paths

Answer

STP prevents broadcast storms caused by Layer 2 loops by electing a root bridge and placing redundant ports in a blocking state.

Question 2

A coaxial cable run in a CATV distribution system shows excessive signal loss. Which tool would best identify the fault location?

Accepted Answer

Time Domain Reflectometer (TDR)

Answer

A TDR sends a signal pulse down the cable and measures the time for reflections to return, identifying faults, shorts, or impedance mismatches and their distance.

Question 3

In a PoE installation, what is the maximum power a PoE+ (802.3at) switch port can deliver to a powered device?

Accepted Answer

30 watts

Answer

PoE+ (802.3at Type 2) delivers up to 30 watts at the powered device (PD), compared to 15.4 watts for standard PoE (802.3af).

Question 4

What is the purpose of a demarcation point (demarc) in a building's network infrastructure?

Accepted Answer

Separates the ISP's responsibility from the customer's internal network

Answer

The demarc is the physical boundary where the service provider's network ends and the customer's premises wiring begins, defining ownership and maintenance responsibility.

Question 5

Which grounding conductor is used to bond the telecommunications equipment rack to the building's grounding system?

Accepted Answer

Telecommunications Bonding Backbone (TBB)

Answer

The Telecommunications Bonding Backbone (TBB) connects the telecommunications main grounding busbar (TMGB) to intermediate grounding busbars (TGB) throughout the building.

(VDV) Voice Data Video Technician Certified Practice Test

(VDV) Voice Data Video Technician Certified Practice Test

VDV Network Infrastructure 4