Cisco CCNP Collaboration 300-815 Questions & Answers

• Question 141:

  What is a description of RTP timestamps or sequence numbers?

  A. The sequence number is used to detect losses.

  B. Timestamps increase by the time "carrying" by a packet.

  C. Sequence numbers increase by four for each RTP packet transmitted.

  D. The timestamp is used to place the incoming audio and video packets in the correct timing order (playout delay compensation).

  Correct Answer: D

  Reference: https://www.cs.columbia.edu/~hgs/rtp/faq.html

• Question 142:

  Which section under the Real-Time Monitoring Tool allows for reviewing the call flow and signaling for a SIP call in real time?

  A. Analysis Manager > Inventory > Trace File Repositories

  B. System > Tools > Trace and Log Central

  C. Voice/Video > Session Trace Log View > Real Time Data

  D. Voice/Video > Session Trace Log View > Open From Local Disk

  Correct Answer: C

  Reference: https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/213583-procedure-to-analyse-call-flow-of-sip-ca.html

• Question 143:

  Cisco SIP IP telephony is implemented on two floors of your company. Afterward, users report intermittent voice issues in calls established between floors. All calls are established, and sometimes they work well, but sometimes there is one-way audio or no audio. It is determined that there is a firewall between the floors, and the administrator reports that it is allowing SIP signaling and UDP ports from 20000 to 22000 bidirectionally. What are two solutions for this issue? (Choose two.)

  A. Go to the SIP profile assigned to these IP phones in Cisco UCM and change the range of media ports to 16384-32767

  B. Ask the firewall administrator to change the ports to TCP.

  C. Ask the firewall administrator to change the range of UDP ports to 16384-32767.

  D. Go to the SIP profile assigned to these IP phones in Cisco UCM and change the range of media ports to 20000-22000.

  E. Go to System Parameters in Cisco UCM and change the range of media ports to 20000-22000.

  Correct Answer: CD

  This question is tricky because it's asking for two separate solutions. The wording suggests that it's not looking for two tasks to become one single solution. In this case, one solution is to change the ports on the SIP profile of the phones to match the ports on the firewall. The other solution is to ask the firewall admin to change his ports to match the ports in UCM.

• Question 144:

  When an administrator troubleshoots H.323 call setup, which message gives an alert that the called party is being notified about the call?

  A. ALERTING

  B. PROCEEDING

  C. CONNECT

  D. RINGING

  Correct Answer: A

• Question 145:

  End users at a new site report being unable to hear the remote party when calling or being called by users at headquarters. Calls to and from the PSTN work as expected. To investigate the SIP signaling to troubleshoot the problem, which field can provide a hint for troubleshooting?

  A. Contact: header of the 200 OK response

  B. Allow: header if the 200 OK response

  C. o= line of SDP content

  D. c= line of SDP content

  Correct Answer: D

• Question 146:

  Why would RTP traffic that is sent from the originating endpoint fail to be received on the far endpoint?

  A. The far end connection data (c=) in the SDP was overwritten by deep packet inspection in the call signaling path.

  B. Cisco UCM invoked media termination point resources.

  C. The RTP traffic is arriving beyond the jitter buffer on the receiving end.

  D. A firewall in the media path is blocking TCP ports 16384-32768.

  Correct Answer: A

• Question 147:

  What is first preference condition matched in a SIP-enabled incoming dial peer?

  A. incoming uri

  B. target carrier-id

  C. answer-address

  D. incoming called-number

  Correct Answer: A

  Reference: https://www.cisco.com/c/en/us/support/docs/voice/ip-telephony-voice-over-ip-voip/211306-In-Depth-Explanation-of-Cisco-IOS-and-IO.html#anc8

• Question 148:

  An administrator is troubleshooting call failures on an H.323 gateway via the CLI. To see signaling for media and call setup, which two debugs should the Administrator turn on? (Choose two.)

  A. debug H.245 asn1

  B. debug H.323 message

  C. debug H.225 asn1

  D. debug H.225 media

  E. debug H.323 asn1

  Correct Answer: AC

• Question 149:

  Which two extended capabilities must be configured on dial peers for fast start-to-early media scenarios (H.323 to SIP interworking)? (Choose two.)

  A. DTMF

  B. BFCP

  C. VIDEO

  D. FAX

  E. AUDIO

  Correct Answer: AB

• Question 150:

  An administrator is troubleshooting a one-way audio issue for a call that uses H.323 protocol in slow-start mode. The administrator requests that the IP and port information of the Real-Time Transport Protocol traffic that had the one-way audio call is provided. The H.225 and H.245 messages for one of the one-way audio calls are gathered and the call flow has not invoked any media resources. Where is the RTP IP and port information for both sides found?

  A. H.245 Terminal Capability Set

  B. H.245 Open Logical Channel

  C. H.225 Connect

  D. H.245 Open Logical Channel Ack

  Correct Answer: D

  Reference: http://ccievoicehopeful.blogspot.com/2012/09/h323-notes.html