VoIP - Voice Over IP Quiz # 2

What is the range of the frequency of a telephone channel?

10 Hz to 9000 Hz

300 Hz to 3400 Hz

200 Hz to 20000 Hz

16 Hz to 1600 Hz

Which of the following are the components of local loop signaling?

Supervisory Signaling

Address Signaling

Trunk Signaling

All of the above

Which of the following is one of the most important things common in all IP phones?

Global Positioning System (GPS)

Bluetooth

Network Interface Card (NIC)

None of the above

Which of the following are the major VoIP protocols?

SIP

H.323

SMTP

MGCP

FTP

RTP

RTCP

What do you call a medium which allows multiple channels?

Multi mode

Single mode

Broadband

Baseband

Which of the following methods is most commonly used to remove echo in telephone networks these days?

Echo Avoidance

Echo Suppression

Echo Cancellation

All of the above

What is the minimum bandwidth required for VoIP to deliver high quality services?

32 kbps

64 kbps

128 kbps

256 kbps

Which of the following statements regarding CRTP is/are false?

CRTP is usually used on slow links i.e. links that have a speed less than 2 Mbps

Enabling CRTP does not add up to processing overhead

Enabling compression on both sides of the link is not required

CRTP can be used to conserve bandwidth on a WAN interface

CRTP is not recommended to be used on fast links i.e. links that have a speed more than 2 Mbps

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

100 ms

125 ms

150 ms

200 ms

Which of the following protocols are assigned ports for each voice call?

RTP in transmit direction

RTCP in transmit direction

RTP in receive direction

RTCP in receive direction

Which of the following classes are used for host addressing?

Class A

Class B

Class C

Class D

Class E

All of the above

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?

Trunk

Local Loop

Demarcation Point

Point of Presence

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?

DHCP

Firewall

NAT

None of the above

Which of the following VoIP protocols define end-to-end call signaling methods?

SIP

MGCP

RTP

H.323

Which of the following is the reason for using UDP instead of TCP for voice transmission?

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

Which of the following has the correct sequence (from the lowest layer to the highest)?

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

State whether true or false:

QSIG is implemented on PRI interfaces only.

True 

False

Which of the following protocols is used in a VoIP call at the application layer of the TCP/IP model?

NTP

RTCP

RTP

All of the above

Which of the following statements are true regarding circuit-switched networks (POTS) and packet-switched networks?

In POTS, if any line is down, a call cannot be made

In POTS, the line never goes down

In packet-switched networks, if any line goes down, the voice packets can still reach their destination by selecting the best alternate route from the available routes

None of the above

For which of the following services is SS7 responsible?

Basic call setup, management and tearing down of connections

Call forwarding

Calling party number display

All of the above

Through which protocols can VPNs be implemented at layer 2?

NTP

PPTP

RTCP

L2TP

State whether true or false

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

True

False 

Which of the following are examples of CCS?

QSIG

Q.933A

SS7

DPNSS

All of the above

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

Router

Switch

Firewall

Server

Which of the following are ITU standards for voice compression?

G.701

G.711

G.726

G.728

G.729

G.729A

All of the above

What are the three main steps required in the analog-to-digital conversion process?

Compression

Encoding

Filtering

Recording

Sampling

Quantization

Which of the following QoS techniques can be used to ensure consistent delivery and throughput of voice packets?

Queuing

Congestion Avoidance

Header Compression

Resource Reservation Protocol

Fragmentation

All of the above

On which of the following IP enabled devices can VoIP telephone services work?

Computer

Personal Digital Assistant (PDA)

IP telephone

All of the above

Which of the following VoIP protocols is an emerging standard for PSTN gateway control?

SIP

MGCP

RTP

H.323

How many bits are there in a MAC address?

32 bits

48 bits

24 bits

16 bits