Which statement is true about IP telephony calls?

To save on intra-office call costs, the Company network has implemented VOIP at all their
locations. Which statement is true about IP telephony calls?

A.
The voice carrier stream uses H.323 to set up, maintain, and tear down call endpoints.

B.
A Voice over IP (VoIP) packet consists of the voice payload, IP header, TCP header, RTP
header, and Layer 2 link header.

C.
Call control signaling uses Real-Time Transport Protocol (RTP) packets that contain
actual voice samples.

D.
The sum of bandwidth necessary for each major application, including voice, video, and
data, should not exceed 75 percent of the total available bandwidth for each link.

E.
None of the other alternatives apply

Explanation:
Voice over Internet Protocol (VOIP) is probably the most feasible among today’s
technologies for data, voice and video integration. VOIP is the technology that uses Internet
Protocol to transmit voice conversations over a data network such as an intranet or the
Internet.
The multisite IP WAN with distributed call processing has the following design
characteristics:
Cisco CallManager or Cisco CallManager cluster at each location (10, 000 users maximum
per site)
Cisco CallManager clusters are confined to a single campus and may not span the WAN
IP WAN as the primary voice path between sites, with the PSTN as the secondary voice
path
Transparent use of the PSTN if the IP WAN is unavailable
Cisco IOS gatekeeper for E.164 address resolution
Cisco IOS gatekeeper for admission control to the IP WAN
Maximum of 100 sites interconnected across the IP WAN using hub and spoke topologies
Compressed voice calls supported across the IP WAN
Single WAN codec supported
DSP resources for conferencing and WAN transcoding at each site

Voice mail and unified messaging components at each site
Minimum bandwidth requirement for voice and data traffic is 56 kbps. For voice, interactive
video, and data, the minimum requirement is 768 kbps. In each case, the bandwidth
allocated to voice, video, and data should not exceed 75% of the total capacity
Remote sites can use Cisco IOS as well as gateways based on the Skinny Gateway
Protocol