CLCOR Quick Quiz — 10 Questions

Question 1

You are troubleshooting intermittent audio quality. You notice that RTCP packets are arriving with high variance. What does this indicate?

Accepted Answer

Jitter. Intermittent audio quality and high variance in RTCP reports point directly to network jitter.

Answer

Latency

Answer

Codec Mismatch

Answer

Packet Loss

Question 2

Which THREE items are included in a standard SIP REGISTER request?

Accepted Answer

To Header. The 'To', 'From', and 'Contact' headers are mandatory in a SIP REGISTER request.

Answer

Alert-Info

Answer

Body (SDP)

Question 3

You are troubleshooting a registration issue where the phone sends a REGISTER request, but the server does not respond. What is the most likely issue?

Accepted Answer

Network Connectivity/Firewall. If the phone sends a request and gets no response, it is a reachability or network path issue (firewall/ACL).

Answer

Incorrect Model

Answer

Device Pool mismatch

Answer

Wrong Password

Question 4

Which command is used to configure the IP address or hostname of the destination device on a dial-peer?

Accepted Answer

session target. session target ipv4:x.x.x.x is the standard way to define the destination IP.

Answer

target ip

Answer

call target

Answer

destination-ip

Question 5

What is the primary function of a dial-peer destination-pattern?

Accepted Answer

To match the dialed number. The destination-pattern defines the number or pattern that triggers the selection of a specific dial-peer.

Answer

To define the codec

Answer

To specify the gateway IP

Answer

To enable SIP

Question 6

A CUBE is configured for H.450.3 call forwarding, but it is not working. What is the most likely cause?

Accepted Answer

Incompatible signaling protocol. H.450.3 is an H.323 supplementary service, which requires specific H.323 configuration and is often incompatible with SIP-based CUBE deployments without proper interworking.

Answer

Dial-peer not defined

Answer

Codec mismatch

Answer

SIP profile missing

Question 7

Which THREE methods are used by Cisco IP phones to obtain their configuration files?

Accepted Answer

Auto-discovery via Service Discovery. DHCP options, manual entry, and auto-discovery/TFTP are standard methods.

Answer

SMTP

Answer

FTP

Question 8

What is the default dial-peer used if no other dial-peer matches a call on a Cisco IOS XE gateway?

Accepted Answer

Dial-peer 0. Dial-peer 0 is the system default dial-peer that acts as a catch-all if no specific match is found.

Answer

Dial-peer none

Answer

Dial-peer 1

Answer

Dial-peer 100

Question 9

Which THREE codecs are natively supported by the Cisco IP Phone 8800 series?

Accepted Answer

Opus. G.711, G.729, and Opus/G.722 are widely supported across the 8800 series.

Answer

H.264

Answer

G.723

Question 10

A CUBE is receiving calls but rejecting them due to '488 Not Acceptable Here'. What is the most likely reason?

Accepted Answer

Codec mismatch. 488 usually indicates a mismatch in media capabilities (codecs or SDP) offered vs what is configured on the dial-peer.

Answer

Authentication failure

Answer

SIP registration expired

Answer

Dial-peer inactive