Chapter Review Questions

The following questions test your knowledge of topics explained in this chapter. You can find the answers to the questions in Appendix A, "Answers to Chapter Review Questions."

1.	Which two functions does a gateway provide? VLAN separation Translation between the VoIP and PSTN network Physical access for analog telephones and fax machines Power over Ethernet to the IP phone Database services
2.	Which protocol provides out-of-band control information for RTP-based call flows? H.225 RAS RTP SNMP RTCP
3.	A company has four sites and wants to implement VoIP at all of them. The requirements include implementing gateway devices with no call-processing intelligence at the remote sites, controlling all call traffic from the headquarters location, and having a single point of CAC. Which network architecture is appropriate to meet these requirements? Single-site architecture Distributed architecture Centralized architecture H.323 gateway architecture
4.	In which of the following situations would a gateway be required? Cisco CallManager-to-IP network connection PBX-to-voice mail connection Key system-to-IP network connection PBX-to-PBX connection
5.	Which function best describes a numbering plan? Determines routes between source and destination Defines a telephone number of a voice endpoint or application Performs digit manipulation when sending calls to the PSTN Performs least-cost routing for VoIP calls
6.	Which worldwide prefix scheme was developed by the ITU to standardize numbering plans? G.114 E.164 G.164 E.114
7.	Which three factors must be considered when calculating the total bandwidth of a VoIP call? CODEC size CRC usage Network-link overhead Sample size Capacity of network links
8.	What is the overhead for Frame Relay? 3 bytes 5 bytes 6 bytes 18 bytes
9.	What is the equivalent of one Erlang? 60 call seconds 36 centum call seconds 3600 centum call seconds 1 minute
10.	Which feature provides transport security for a VoIP network? Encryption and data authentication Inspection of traffic at the firewall Proactive notification of an attempted attack Intrusion detection