Troubleshooting Cisco IP Telephony and Video (CTCOLLAB)

Here you have the best Cisco 300-080 practice exam questions

You have 157 total questions to study from
Each page has 5 questions, making a total of 32 pages
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This questions were last updated on December 14, 2025
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Question 1 of 157

An IP phone that is connected through a Cisco Catalyst 3750 Series Switch is failing to register with the subscriber as a backup server. When the user presses the settings button on the phone, only the Cisco Unified Communications Manager publisher shows as registered. What is the most likely cause for this issue?

The phone does not have the correct Cisco Unified Communications Manager group in the device configuration page.

The Cisco Unified Communications Manager group that is applied through the device pool is misconfigured.

The ip-helper address command for the subscriber is not configured on the switch port.

The subscriber does not have the correct device pool configured.

The enterprise phone configuration does not have the call control redundancy enabled.

Correct Answer: B

Question 2 of 157

Refer to the exhibit.
Exam 300-080: Question 2 - Image 1

An IP phone that is connected through a Cisco Catalyst 3750 Series Switch is failing to register with Cisco Unified Communications Manager. When the user presses the settings button on the phone, the Operational VLAN ID shows a blank entry. What is the most likely cause for this issue?

The switch may not be supplying inline power.

The spanning tree portfast command needs to be removed.

The trunk encapsulation is missing. The trunk must be configured for dot1.Q.

Cisco Discovery Protocol is disabled on the switch.

The Operational VLAN ID of the phone always shows as blank. The Admin. VLAN ID should be 110.

Correct Answer: D

Question 3 of 157

You configured a Cisco ISR G2 as a SIP gateway, but the gateway does not show that it is registered with Cisco Unified Communications Manager. What is causing this issue?

Cisco Unified Communications Manager does not support SIP gateways.

The gateway does not have the UC license installed.

The gateway does not have Cisco Unified Border Element session licensing.

Cisco Unified Communications Manager does not show a SIP gateway as registered if it is not properly configured.

Cisco Unified Communications Manager never shows a SIP gateway as registered even when it is properly configured.

The Cisco ISR G2 cannot be a SIP gateway.

Correct Answer: E

Question 4 of 157

Which issue would cause an MGCP gateway to fail to register with Cisco Unified Communications Manager?

missing the configuration command isdn bind-l3 ccm-manager under the ISDN interface

mismatched domain name on the MGCP gateway and Cisco Unified Communications Manager gateway configuration

misconfigured route group in Cisco Unified Communications Manager

incorrect MGCP IP address specified in the gateway configuration in Cisco Unified Communications Manager

Correct Answer: B

Question 5 of 157

Endpoints are configured for both H.323 and SIP using the same URI and Cisco VCS settings, but the endpoints register only as H.323 endpoints. What is causing this issue?

A firewall is blocking all traffic from the endpoints to the Cisco VCS.

The Cisco VCS has no SIP domains configured.

The Cisco VCS is blocking the endpoints because of duplicate ID entries.

The endpoints do not have the SIP option key installed.

SIP does not work, because SIP is used for Cisco Unified Communications Manager registration only.

Correct Answer: B