Cisco CIVND

Question 1

What is the basis of analog video broadcasting?

Answer 1

Frequency Division Multiplexing (FDM)

Question 2

What are the analog video broadcasting standards?

Answer 2

NTSC, PAL, and SECAM

Question 3

What are the video signaling protocols?

Answer 3

ISDN, H.323, SIP, SCCP

Question 4

Explain the two variations of ISDN.

Answer 4

BRI = 1 D channel plus 2 Bearer channels (64 Kbps each)
PRI = 1 D plus 23 B

Question 5

Describe the protocols that make up H.323.

Answer 5

H.225 - signaling
H.245 - negotiate media (ports, codecs, etc.)
H.450 - supplementary services (hold, transfer, retrieve, etc.)

Question 6

What are the 5 components of SIP?

Answer 6

User Agent Client
User Agent Server
Registrar Server
Proxy Server
Redirect Server

Question 7

What carries the media stream after signaling establishes the connection?

Answer 7

RTP (Real-Time Transport Protocol)

Question 8

How does RTP know the correct order to deliver packets?

Answer 8

RTP includes a sequence number.

Question 9

What is the RTP port range?

Answer 9

16384 - 32768

Question 10

Explain RTCP as it relates to RTP.

Answer 10

It provides call statistics and always uses the odd number port immediately after the even number RTP port.

Question 11

List the video codecs.

Answer 11

MPEG-1
MPEG-2
MPEG-4 / H.264

Question 12

List the audio codecs and associated bandwidth.

Answer 12

G.711 (64 Kbps), G.729 (8 Kbps), and iLBC (15.2 Kbps)

Question 13

Explain the properties of the MPEG-4 / H.264 codec.

Answer 13

Bandwidth efficient, AAC, DRM, high quality, low bit-rate.

Question 14

How many FPS is 50I?

Answer 14

25 frames per second

Question 15

Explain the difference between Interlacing and Progressive.

Answer 15

Interlacing splits each frame into 2 - 1 with odd lines and another with even lines. Progressive shows the entire frame.

Question 16

Explain the difference between multipoint/multisite and multiway.

Answer 16

This refers to telepresence endpoint capabilities to support multiple parties in the same call. Multipoint/multisite is the ability of the endpoint itself to mix the streams. Multiway engages external hardware resource called an MCU.

Question 17

What is maximum number of participants supported on a Cisco telepresence endpoint with the multisite license?

Answer 17

4 (endpoint hosting the conference plus 3 others)

Question 18

Explain the difference between VCS Control/Expressway and Expressway Core/Edge.

Answer 18

VCS Control is used to register endpoints and call control.
VCS Expressway allows firewall traversal for external calls.
Expressway Core/Edge allow an endpoint outside the firewall to register with CUCM inside the firewall. It does not provide call control.

Question 19

Describe the benefits of Cisco Discovery Protocol (CDP)

Answer 19

CDP can discover the amount of PoE power needed for an endpoint.

CDP sends the voice VLAN information.

Question 20

What is the open standard equivalent of Cisco Discovery Protocol (CDP)?

Answer 20

LLDP[-MED] - MED provides supplementary services like PoE power and voice VLAN info.

Question 21

What is the DHCP option that points an endpoint to the TFTP server for configuration download?

Answer 21

Option 150. Option 66 is an lesser-used alternative that uses hostname/DNS to lookup the TFTP server.