Cisco CCNP 642-845 考題分享
CCNP全稱是：Cisco Certified Network Professional——思科認證網絡高級工程師.

    CCNP認證(思科認證網絡專業人員)表示通過認證的人員具有豐富的網絡知識。獲得CCNP認證的專業人員可以為具有100到500多個節點的大型企業網絡安裝、配置和運行LAN、WAN和拔號訪問業務。

    獲取CCNP認證必備條件是:

    必須首先通過CCNA認證。CCNP考試從1998年設立以來經過多次更改，目前考取最新CCNP有兩種途徑：壹是901+812+825+845，另外壹種是892+825+845。

下麵是642-845 題庫的部份exam，如想了解更多請訪問：http://www.51-pass.com/642-845.html

6. Voice activity detection (VAD) suppresses the transmission of silence patterns. On average, and
assuming that a link carries at least 24 calls, what percentage of total bandwidth could VAD save?
Select the best response.
A. 5
B. 15
C. 25
D. 35
E. 45
F. 55
Answer: D
7. Two sites are using a multisite centralized call processing model. The voice gateway on the remote
branch has lost IP connectivity to its Cisco CallManager server. Which feature enables the remote
gateway to take the role of the call agent during the WAN failure?
Select the best response.
A. automated alternate routing (AAR)
B. Cisco CallManager Attendant Console
C. real-time protocol (RTP)
D. Survivable Remote Site Telephony (SRST)
Answer: D
9. To have the best possible voice quality and to utilize effectively the available bandwidth, which queuing
and compression mechanisms need to be used? (Choose two.)
Select 2 response(s).
A. class-based weighted fair queuing (CBWFQ)
B. low latency queuing (LLQ)
C. priority queuing (PQ) or custom queuing (CQ)
D. Real-Time Transport Protocol (RTP) header compression
E. TCP header compression
F. UDP header compression
Answer: BD
10. Which three statements about end-to-end delay are true? (Choose three.)
Select 3 response(s).
A. End-to-end delay is the sum of propagation delays, processing delays, serialization delays, and
queuing delays.
B. Coast-to-coast end-to-end delay over an optical link is about 20 ms.
C. Processing delay depends on various factors, which include CPU speed, CPU utilization, IP switching
mode, and router architecture.
D. Propagation and serialization delays are related to the media.
E. Propagation delay is the time it takes to transmit a packet and is measured in bits-per-second (bps).
F. Serialization delay is the time it takes for a router to take the packet from an input interface and put it
into the output queue of the output interface.
Answer: ACD
11. What three statements are true about the various deployments of the 802.1x Extensible Authentication
Protocol (EAP)? (Choose three.)
Select 3 response(s).
A. EAP-FAST has the ability to tie login with non-Microsoft user databases.
B. EAP-TLS supports static passwords.
C. PEAP supports one-time passwords.
D. LEAP does not support multiple operating systems.
E. LEAP supports Layer 3 roaming.
F. PEAP does not work with WPA.
Answer: ACE

CCNP全稱是：Cisco Certified Network Professional——思科認證網絡高級工程師.

    CCNP認證(思科認證網絡專業人員)表示通過認證的人員具有豐富的網絡知識。獲得CCNP認證的專業人員可以為具有100到500多個節點的大型企業網絡安裝、配置和運行LAN、WAN和拔號訪問業務。

    獲取CCNP認證必備條件是:

    必須首先通過CCNA認證。CCNP考試從1998年設立以來經過多次更改，目前考取最新CCNP有兩種途徑：壹是901+812+825+845，另外壹種是892+825+845。

下麵是642-845 題庫的部份exam，如想了解更多請訪問：http://www.51-pass.com/642-845.html

1. Which two QoS statements are true about the use of the SDM QoS wizard? (Choose two.)
Select 2 response(s).
A. Business-critical traffic includes VoIP and voice signaling packets.
B. SDM can be used to configure a basic QoS policy for incoming traffic on WAN interfaces and IPsec
tunnels.
C. SDM can provide QoS for real-time traffic and business-critical traffic.
D. SDM creates a custom-queuing (CQ) or a priority-queuing (PQ) policy.
E. SDM creates a low latency queuing (LLQ) service policy with its associated classes.
F. When allocating bandwidth, values can be entered in either bandwidth percentage or kilobytes per
second (kBps).
Answer: CE
2. Which two statements regarding the Wireless LAN Solution Engine (WLSE) are true? (Choose two.)
Select 2 response(s).
A. To support fault and policy reporting, the WLSE requires a Wireless Control System (WCS).
B. When WLSE detects an AP failure, it automatically increases the power and cell coverage of nearby
APs.
C. WLSE requires the 2700 location appliance to offer location tracking.
D. WLSE can locate rogue APs and automatically shut them down.
E. WLSE configuration is done using the command line interface (CLI) or a WEB based template.
Answer: BD
3. Which two statements are true about the function of CAC? (Choose two.)
Select 2 response(s).
A. CAC provides guaranteed voice quality on a link.
B. CAC artificially limits the number of concurrent voice calls.
C. CAC is used to control the amount of bandwidth that is taken by a call on a link.
D. CAC prevents oversubscription of WAN resources that is caused by too much voice traffic.
E. CAC allows an unlimited number of voice calls while severely restricting, if necessary, other forms of
traffic.
F. CAC solves voice congestion problems by using QoS to give priority to UDP traffic.
Answer: BD
4. Which two statements are true about the implementation of QoS? (Choose two.)
Select 2 response(s).
A. Implementing DiffServ involves the configuration of RSVP.
B. Implementing IntServ allows QoS to be performed by configuring only the ingress and egress devices.
C. Implementing IntServ involves the utilization of RSVP.
D. Traffic should be classified and marked by the core network devices.
E. Traffic should be classified and marked as close to the edge of the network as possible.
Answer: CE
5. Which codec standard would provide the highest voice-quality, mean opinion score (MOS)?
Select the best response.
A. G.711, PCM
B. G.728, LDCELP
C. G.729, CS-ACELP
D. G.729A, CS-ACELP
Answer: A