Cisco 400-051 Online Practice Questions and Exam Preparation

Cisco 400-051 Online Questions & Answers

• Question 81:

  Which Call Admission Control mechanism is supported for the Cisco Extension Mobility Cross Cluster solution?

  A. Location CAC
  B. RSVP CAC
  C. H.323 gatekeeper
  D. intercluster Enhanced Location CAC
  E. visiting cluster's LBM hub
  B. RSVP CAC

  ---

  Configuring extension mobility cross cluster (EMCC) is nothing you should take lightly. EMCC requires a lot of configuration parameters including the exporting and importing of each neighbor cluster's X.509v3 digital certificates. EMCC is supported over SIP trunks only. Presence is another feature that's only supported over SIP trunks. If you want to be able to perform scalable Call Admission Control (CAC) in a distributed multi-cluster call processing model, you will need to point an H.225 or Gatekeeper controlled trunk to an H.323 Gatekeeper for CAC... but if you want to support presence and EMCC between clusters and maintain CAC.

• Question 82:

  Which of the below characteristics of RPL is true?

  A. RPL is designed for lossy networks.
  B. RPL can send only messages in secured mode.
  C. RPL uses hello messages to send routing updates to its neighbors.
  D. RPL is an IPv6 link-state routing protocol.
  A. RPL is designed for lossy networks.

• Question 83:

  Assume a 30-millisecond voice payload, 6 bytes for the Layer 2 header, 1 byte for the end-of-frame flag, and the IP, UDP, and RTP headers are compressed to 2 bytes, how much bandwidth should be allocated to the strict priority queue for eight VoIP calls that use a G.729 codec over a multilink PPP link with cRTP enabled?

  A. 121.6 kb/s
  B. 92.8 kb/s
  C. 88.4 kb/s
  D. 83.2 kb/s
  E. 78.4 kb/s
  D. 83.2 kb/s

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  References: http://www.cisco.com/en/US/tech/tk652/tk698/technologies_tech_note09186a0080094ae2.shtml

• Question 84:

  Which three softkeys can be offered on a Cisco IP Phone 7965, running SCCP firmware, when it is in Remote In Use state? (Choose three.)

  A. Resume
  B. EndCall
  C. Select
  D. Barge
  E. NewCall
  F. cBarge
  G. Join
  D. Barge
  E. NewCall
  F. cBarge

• Question 85:

  A customer is trying to configure Cisco Unified Communications Manager IM and Presence to support open XMPP federation and asks you which DNS SRV record(s) must be created in the public DNS server. Assume that the Cisco Unified

  Communications Manager IM and Presence is using "Default Domain" IM Address Scheme with domain customer.com.

  Which DNS SRV record(s) must be created?

  A. _xmpp-server_tcp.customer.com
  B. _xmpp-client_tls.customer.com
  C. _xmpp-server_tls.customer.com
  D. _xmpp-server_udp.customer.com
  E. _xmpp-client_tcp.customer.com
  A. _xmpp-server_tcp.customer.com

• Question 86:

  Refer to the exhibit. An engineer is analyzing a SIP call between the Cisco Unified Communications Manager on the left to Cisco Unified Border Element on the right. Based on information displayed, which behavior can be determined from the exhibit?

  

  A. The midcall-signaling block command is configured on Cisco Unified Border Element so re-invites are not consumed.
  B. The call has interworking issues where the user is not experiencing audio.
  C. The call is terminated because the 200 OK messages are not arriving to Cisco Unified Communications Manager.
  D. The mid-call re-invite negotiated for Call Hold/Resume supplementary service.
  D. The mid-call re-invite negotiated for Call Hold/Resume supplementary service.

• Question 87:

  Which two parameters, in the reply of an MGCP gateway to an Audit Endpoint message, indicate to a Cisco Unified CM that it has an active call on an endpoint? (Choose two)

  A. Bearer Information
  B. Call ID
  C. Capabilities
  D. Connection ID
  E. Connection Parameters
  F. Connection Mode
  B. Call ID
  D. Connection ID

• Question 88:

  Refer to the exhibit.

  

  Which user agent has the recipient role in this SIP REFER call transfer?

  A. user agent A
  B. user agent B
  C. user agent C
  D. user agent B and C
  E. user agent A and B
  B. user agent B

  ---

  The Refer method has three main roles:

  ?Originator--User agent that initiates the transfer or Refer request.

  ?Recipient--User agent that receives the Refer request and is transferred to the final-recipient.

  ?Final-Recipient--User agent introduced into a call with the recipient.

  References: http://www.cisco.com/c/en/us/td/docs/ios_xr_sw/iosxr_r3-4/sbc/configuration/guide/sbc_c34/sbc34stx.pdf

• Question 89:

  Which SIP request is used by Cisco Unified Communications Manager to signal DND status changes to a Cisco 9971 IP Phone?

  A. OPTIONS
  B. NOTIFY
  C. INFO
  D. REFER
  E. UPDATE
  D. REFER

  ---

  Cisco Unified Communications Manager supports Do Not Disturb that a SIP device initiates or that a Cisco Unified Communications Manager device initiates. A DND status change gets signaled from a SIP device to Cisco Unified Communications Manager by using the SIP PUBLISH method (RFC3909). A DND status change gets signaled from a Cisco Unified Communications Manager to a SIP device by using a dndupdate Remote-cc REFER request. Cisco Unified Communications Manager can also publish the Do Not Disturb status for a device, along with the busy and idle status for the device.

  References: http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/6_1_1/ccmfeat/cmfsgd611/fsdnd.html

• Question 90:

  Which entity signs a Cisco IP phone LSC?

  A. Godaddy.com Enrollment Server
  B. Manufacturer Certificate Authority
  C. Registration Authority
  D. Certificate Authority Proxy Function
  E. Cisco Certificate Authority
  D. Certificate Authority Proxy Function

  ---

  By default, LSC certificates are not installed on Cisco IP phones. Cisco IP phones that are required to use LSC certificates must be provisioned to allow TLS transactions before deployment in the field. LSC certificates can be provisioned to the Cisco IP phones through the Certificate Authority Proxy Function (CAPF) process. This process is completed using TLS and USB tokens coupled with the CTL client. Moreover, the Cisco ASA Phone Proxy feature can serve LSC certificates to the Cisco IP phones. Cisco IP phones will only work with the Cisco ASA Phone Proxy and will not establish secure connectivity with the Cisco Unified Communications Manager.