Nortel Technology Standards and Protocol for IP Telephony Solutions

Transcription

1 1 Nortel Technology Standards and Protocol for IP Telephony Solutions QUESTION: 1 To achieve the QoS necessary to deliver voice between two points on a Frame Relay network, which two items are required to guarantee that voice quality is maintained? (Choose two.) Assume that a Permanent Virtual Circuit (PVC) is available to address converged voice and data. A. a Variable Bit Rate (VBR) service type B. a WAN access device that shapes traffic C. a WAN access device that does NOT fragment voice IP packets D. a WAN access device that can managefirst-in, First-Out (FIFO) queuing E. a Committed Information Rate (CIR) large enough to address the total peak voice traffic plus a portion allocated for Best-Effort (BE) data Answer: B,E QUESTION: 2 A video conference is in progress between two networked locations using gigabit Ethernet. The video conferencing application is using User Datagram Protocol (UDP) to transport the video and audio data. Why should UDP be used instead of Transmission Control Protocol (TCP)? A. TCP CANNOThandle streaming data applications. B. UDP is better than TCP at seamlessly synchronizing voice and video together. C. UDP serves as an efficient transport for handling real-time application traffic. D. UDP uses less bandwidth than TCP in a WAN, but more bandwidth than TCP in a LAN. QUESTION: 3 How does Real-Time Control Protocol (RTCP), the control protocol of Real-Time Protocol (RTP), assist RTP in handling packetized voice in an IP telephony environment? A. Controls the RTP data flows. B. Identifies sources and providesqos feedback. C. Interoperates with Transmission Control Protocol (TCP). D. Controls the network bandwidth used by RTP data flows.

2 2 Answer: B QUESTION: 4 The basic attributes of Real-Time Protocol (RTP) provide for support of applications like voice and video. Which three attributes of RTP support real-time applications? (Choose three.) A. Timestamping B. Packet sequencing C. Header compression D. Payload identification E. Packet retransmission,b,d QUESTION: 5 What are two differences between IP, Asynchronous Transfer Mode (ATM) and Frame Relay (FR)? (Choose two.) A. ATM has a fixed cell size, but IP and FR do NOT. B. FR has built in mechanisms within the protocol forqos. C. ATM is connectionless, but IP and FR are connection oriented. D. IP is a Layer 3 protocol, but ATM and FR are Layer 2 protocols. QUESTION: 6 To implement VoIP on a customer's IP network, which transport protocol should you use to best meet the real-time requirement for VoIP, and why? A. User Datagram Protocol (UDP); It ignores lost packets. B. Transmission Control Protocol (TCP); It retransmits lost packets. C. User Datagram Protocol (UDP);The amount of delay time is bounded. D. Transmission Control Protocol (TCP);The amount of delay time is bounded. QUESTION: 7 A customer has a mix of Layer 2 and Layer 3 switches in their LAN. To ensure the best QoS as they implement VoIP, which two QoS methods should you recommend? (Choose two.)

3 3 A q B. Weighted Fair Queuing (WFQ) C. Random Early Detection (RED) D. Differentiated Services (DiffServ) QUESTION: 8 During the first phase of a network assessment you discover the customer forces all switch ports to 100 Mbps full duplex. The customer plans to deploy an IP-enabled Private Branch Exchange (PBX) and Internet Telephones. Which network recommendation should you propose to the customer? A. Install all devices with default settings. B. Require all VoIP components toautonegotiate. C. Force the Internet gateways to 100 Mbps full duplex. D. Force the Internet gateways to 100 Mbps full duplex and let the Internet Telephonesautonegotiate. Answer: B QUESTION: 9 The following VoIP network assessment steps have already been completed for a customer's data network: 1- Estimation of VoIP traffic 2- Assessment of LAN/WAN resources 3- Capacity is available for VoIP Which step should you perform next? A. Implement p/q in the LAN. B. Determine network protocol usage. C. Measure the network ability to provideqos. D. Implement the proposed VoIP network solution. QUESTION: 10

4 4 A company requires a 30-day assessment performed on its network. Which tool is best suited for gathering the necessary data to ensure a successful VoIP deployment without requiring an engineer on-site for the duration of the testing? A. Sniffer Pro B. TraceRoute C. NetIQ Chariot D. HPOpenview QUESTION: 11 Before beginning a network assessment of a customer's data network for VoIP, why is it important to understand the customer's perception of *good or acceptable voice quality? A. It will affect the CODEC(s) selected for the network. B. It will have minimal impact on the assessment of the network. C. It will affect the understanding of the network traffic requirements. D. It will affect the prioritization of voice over data traffic on the network. QUESTION: 12 When assessing a customer's data network for VoIP, which two factors are critical in determining consistent voice quality? (Choose two.) A. packet loss B. routing protocols C. packet recovery rate D. peak delay times and jitter over a given link QUESTION: 13 A geographically dispersed company with a mobile work force wants to quickly and easily deploy Internet Telephones. Which device in the company LAN/WAN network can enable a simplified implementation of Internet Telephones? A. router B. VoIP gateway

5 5 C. network management application D. Dynamic Host Configuration Protocol (DHCP) server Answer: D QUESTION: 14 Which tool is used to measure maximum jitter? A. NetIQ Chariot B. HPOpenView C. Multi Router TrafficGrapher D. Simple Network Management Protocol (SNMP) Management Console QUESTION: 15 When a call is placed from an H.323 endpoint to another H.323 endpoint via an IP network, what is the function of the H.323 gatekeeper? A. It maps the originating gateway IP address to destination gateway IP address. B. It maps the originating telephone number to the originating gateway IP address. C. It maps the destination telephone number to the destination gateway IP address. D. It maps the destination telephone number to the destination endpoint IP address. Answer: D QUESTION: 16 A customer wants to implement VoIP on their LAN. Which two network devices should be used to avoid network congestion? (Choose two.) A. routers B. Ethernet hubs C. Layer2 switches D. Layer3 switches E. shared-media Ethernet hubs,d QUESTION: 17