CLCOR Practice Questions 1 — 50 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

Question 11

Which TWO of the following are valid components of a Cisco IOS voice gateway configuration?

Accepted Answer

Dial-peers. Dial-peers and voice translation rules are core components of voice gateway configuration.

Answer

Phone button template

Answer

CUCM route pattern

Answer

Device pool

Question 12

Which THREE commands are used to configure a SIP profile in CUBE?

Accepted Answer

voice-class sip-profiles apply. SIP profiles require creating a voice class, defining the match/modify rules, and applying it to a dial-peer.

Answer

dial-peer voice

Answer

sip-ua

Question 13

Which TWO of the following are required to successfully register a CUBE with a SIP provider?

Accepted Answer

authentication credentials. CUBE registration requires a SIP-UA configuration defining the authentication credentials and the registrar server.

Answer

voice class codec

Answer

dial-peer voice

Answer

voice translation-rule

Question 14

Which component in CUBE is responsible for ensuring that the call session is terminated correctly?

Accepted Answer

SIP Stack. The SIP gateway functionality in IOS XE handles the SIP signaling state machine for call termination.

Answer

Dial-peer

Answer

Voice translation-profile

Answer

Voice-class codec

Question 15

Which TWO of the following are true regarding the use of voice translation-rules?

Accepted Answer

They use regular expressions. Translation rules use regular expressions to match and replace digits.

Answer

They perform load balancing

Answer

They replace the SIP protocol

Answer

They define the codec

Question 16

Which THREE of the following are required for the successful operation of the Webex Hybrid Calendar service? (Choose three)

Accepted Answer

A valid configuration in Control Hub.. The Hybrid Calendar requires a properly configured service account, the connector host (Expressway), and an integration configuration in Control Hub.

Answer

A Cisco Unified Communications Manager cluster.

Answer

A public PSTN trunk.

Question 17

When configuring Hybrid Call Service for Cisco Unified Communications Manager, which specific requirement must be met for the Expressway-C and Expressway-E pair?

Accepted Answer

They must be configured with a Unified Communications traversal zone.. The Expressway pair must be registered with the Webex cloud to enable the connector, and specific traversal zones must be configured to pass the signaling traffic.

Answer

They must use the same certificate authority as the CUCM nodes.

Answer

They must use a public IP address on the Expressway-C.

Answer

They must be in the same subnet.

Question 18

When troubleshooting a Hybrid Service, you need to collect 'Diagnostic Logs'. Where do you download these from?

Accepted Answer

The Expressway-C Maintenance > Diagnostics page.. The Expressway provides a dedicated 'Maintenance > Diagnostics' section where you can generate and download comprehensive log bundles for support analysis.

Answer

The Webex App settings menu.

Answer

The Cisco CLI using the 'log collect' command.

Answer

Control Hub under the Troubleshooting tab.

Question 19

What is the maximum number of nodes in a standard Expressway-C cluster for Hybrid Services?

Accepted Answer

6. A standard Expressway-C cluster supports up to six nodes to ensure high availability and scalability.

Answer

8

Answer

4

Answer

2

Question 20

Where in Webex Control Hub do you verify the health status of Hybrid Service connectors?

Accepted Answer

Services tab. The 'Services' tab within Control Hub provides a dashboard for all deployed Hybrid Services and their connector health.

Answer

Troubleshooting tab

Answer

Devices tab

Answer

Users tab