Troubleshooting Cisco IP Telephony & Video v1.0 Free Practice Test — 30 Questions

Question 1

A multinational corporation is undergoing a rapid rollout of Cisco video conferencing endpoints across multiple continents. Midway through the deployment, a new cybersecurity directive mandates stricter encryption protocols for all real-time media traffic, significantly altering the configuration requirements for the Cisco Expressway and Cisco Meeting Server components. The project timeline remains aggressive, and the original deployment plan is now largely obsolete. Which behavioral competency is most critical for the lead troubleshooter to effectively navigate this unforeseen challenge and ensure successful project completion?

Accepted Answer

Adaptability and Flexibility

Question 2

An enterprise\'s Cisco Unified Communications Manager (CUCM) cluster is experiencing sporadic call setup failures specifically related to the audio path for internal extensions, while external calls are functioning correctly. The troubleshooting team has verified that both SCCP and SIP signaling messages are being exchanged successfully, and all IP phones are properly registered with the cluster. Analysis of network captures indicates that the signaling is complete, but the RTP streams are not being established between the endpoints. Which of the following is the most probable root cause for this specific type of media path disruption?

Accepted Answer

Malfunction or resource contention within the Cisco IP Voice Media Streaming Application or Cisco IP Voice Media Application services.

Question 3

A critical IP telephony cluster experiences widespread call quality degradation and intermittent registration failures immediately following a scheduled firmware upgrade on the central call processing manager. Initial diagnostics reveal high CPU utilization on the manager and packet loss on specific voice VLANs. The IT director demands an immediate resolution and a clear explanation of the cause and preventative measures, emphasizing minimal disruption to business operations. Which approach best balances immediate service restoration with thorough root cause analysis and future prevention?

Accepted Answer

Execute an immediate rollback of the call processing manager firmware to the previous stable version, followed by a detailed analysis of the failed firmware update in a controlled lab environment to identify the specific bug, and then communicate findings and a plan for re-deployment with the vendor.

Question 4

A distributed enterprise reports widespread, intermittent audio degradation affecting users across multiple branch offices utilizing Cisco Unified Communications Manager (CUCM) for their IP telephony and Cisco Webex integration. Initial network diagnostics have ruled out significant bandwidth saturation, packet loss on the WAN, and jitter exceeding acceptable thresholds for both signaling and media traffic. Endpoint hardware diagnostics on a sample of affected Cisco IP Phones and soft clients show no anomalies. A network administrator suspects a deeper issue within the call control infrastructure. Which of the following areas within the CUCM cluster is most likely to be the root cause of these audio quality issues, considering the observed symptoms and the troubleshooting steps already performed?

Accepted Answer

Inefficient signaling message processing within the CUCM's SCCP/SIP stacks, leading to delayed or corrupted media path establishment instructions.

Question 5

A multinational corporation has recently deployed a new Cisco Unified Communications Manager (CUCM) cluster across its global offices. Shortly after, users in several locations began reporting sporadic call drops and noticeable audio artifacts during conversations, predominantly affecting those connected via the corporate Wi-Fi. Initial checks confirm that all IP phones are registered correctly with CUCM, and basic network connectivity is established. The IT team suspects a network-related issue, as the problems are intermittent and more pronounced for wireless users. While some Quality of Service (QoS) policies were implemented during the initial setup, their efficacy in handling the dynamic nature of wireless traffic and ensuring consistent real-time media transport is now in question.

Which of the following is the most probable underlying technical deficiency that needs to be addressed to resolve these persistent issues?

Accepted Answer

The existing Quality of Service (QoS) configuration lacks sufficient prioritization mechanisms to guarantee consistent performance for real-time traffic across the converged network, particularly on the wireless segments.

Question 6

A network administrator is troubleshooting an issue where users are reporting that dialing certain internal extensions, which are not assigned to any active phones or hunt groups, results in a call failure with an \"all circuits are busy\" message. Upon reviewing CUCM logs and configurations, it\'s determined that these extensions do not correspond to any configured Directory Numbers (DNs) or hunt pilots. Which of the following is the most accurate description of the underlying behavior of CUCM when encountering such unassigned dialed numbers, assuming no specific \"unassigned number\" manipulation has been configured?

Accepted Answer

The call is terminated with a specific "number not in service" or similar indication, as per default CUCM call routing logic for unassigned DNs.

Question 7

A remote branch office reports that several Cisco IP phones are failing to register with the central Cisco Unified Communications Manager cluster. Upon initial investigation, it\'s confirmed that the phones are physically connected to the network, receiving power, and the local network infrastructure appears operational. Despite these checks, the phones display a \"Registration Rejected\" or \"Unprovisioned\" message. Which of the following troubleshooting approaches would be the most effective initial step to diagnose and resolve this widespread registration issue?

Accepted Answer

Verify the DHCP scope configuration for the branch office's IP subnet, ensuring it has sufficient available IP addresses and the correct TFTP server option (Option 150 or equivalent) is being provided to the IP phones.

Question 8

Consider a scenario within a geographically dispersed Cisco IP Telephony deployment where the primary TFTP server for a specific cluster experiences an unexpected and complete service outage. Which of the following consequences would most critically and immediately affect the operational status of a significant portion of the IP phone endpoints across the affected cluster, thereby disrupting call processing capabilities?

Accepted Answer

Widespread inability of IP phones to register with the Cisco Unified Communications Manager cluster.

Question 9

A distributed enterprise network employing Cisco IP telephony services is experiencing widespread, intermittent audio artifacts, including choppiness and dropped syllables, affecting users across multiple branch offices connected via a multiprotocol label switching (MPLS) Wide Area Network (WAN). Initial diagnostics on the Cisco Unified Communications Manager (CUCM) and individual IP phones reveal no specific device failures or signaling anomalies. The problem appears to be correlated with periods of increased data traffic on the WAN links. Which of the following diagnostic approaches would most effectively isolate the root cause of this audio degradation?

Accepted Answer

Perform end-to-end Quality of Service (QoS) policy verification on all WAN edge routers and intermediate WAN devices, focusing on voice traffic classification, marking (DSCP), and queuing mechanisms.

Question 10

A company recently upgraded its IP telephony system to a Cisco Unified Communications Manager (CUCM) cluster, serving a global user base. Post-deployment, users in remote branch offices are reporting intermittent call drops and poor audio clarity, particularly during peak business hours. Initial log analysis from CUCM and Cisco IP phones indicates high levels of packet loss and jitter affecting voice media streams. The network team has confirmed no significant hardware failures on the CUCM servers themselves. Which fundamental troubleshooting approach, focusing on the interplay between the IP telephony application and the network infrastructure, best explains the root cause and guides an effective resolution strategy in this scenario?

Accepted Answer

Prioritizing the implementation of end-to-end Quality of Service (QoS) policies, including classification, marking, queuing, and shaping of voice and video traffic across all WAN segments to guarantee performance for real-time media.

Question 11

A network operations center is investigating recurring instances of degraded voice quality, characterized by choppy audio and dropped packets, affecting Cisco IP phones during periods of high network utilization. Initial diagnostics confirm that Quality of Service (QoS) markings are correctly applied on edge devices, and the available bandwidth on core links appears sufficient under normal load. The problem escalates significantly between 9:00 AM and 11:00 AM daily. Which strategic adjustment within the Cisco Unified Communications Manager environment would most effectively address this persistent issue by managing real-time traffic flow and resource allocation during peak operational demands?

Accepted Answer

Fine-tuning Call Admission Control (CAC) policies and optimizing Media Resource Management (MRM) configurations within CUCM.

Question 12

A distributed enterprise network supporting Cisco IP Telephony & Video experiences recurring, but not constant, call setup failures exclusively for inbound calls originating from external geographic locations. A specific user group, comprising remote employees connecting via VPN and on-premises staff, reports these failures. Internal calls and outbound calls function without issue. Analysis of the network infrastructure reveals no widespread outages or equipment malfunctions. Which of the following is the most probable primary cause for this intermittent inbound call failure scenario?

Accepted Answer

Intermittent signaling or media path misconfigurations on the Session Border Controller (SBC) or the gateway interfacing with the external telephony provider.

Question 13

A company\'s newly deployed Cisco Unified Communications Manager (CUCM) cluster is experiencing sporadic call setup failures when users at a remote branch office attempt to place outbound calls. Initial diagnostics confirm stable network connectivity between the CUCM cluster and the branch, and the CUCM servers themselves show no critical errors. Reviewing Call Detail Records (CDRs) for the failed calls reveals that the SIP INVITE messages destined for the Public Switched Telephone Network (PSTN) gateway are consistently receiving a `503 Service Unavailable` response. Subsequent examination of the PSTN gateway\'s system logs shows a pattern of `Resource Unavailable` error messages directly correlating with the times of the reported call failures, specifically referencing the trunk servicing the affected branch office. Considering the provided diagnostic information, what is the most probable root cause of these intermittent call setup failures?

Accepted Answer

The PSTN gateway is experiencing resource exhaustion for the specific trunk servicing the branch office.

Question 14

Consider a scenario where a network administrator is monitoring the performance of a Cisco Unified Communications Manager cluster. The administrator notices a slight, intermittent increase in call setup latency across several user groups, but no critical alarms are currently active, and all services are reported as operational. Which of the following actions best demonstrates the behavioral competency of Initiative and Self-Motivation in this context?

Accepted Answer

Demonstrating proactive identification of potential system bottlenecks and initiating diagnostic procedures before critical impact

Question 15

A multinational corporation\'s global voice network, built on Cisco Unified Communications Manager and Cisco IP Phones, is experiencing sporadic and widespread call establishment failures. These failures are most pronounced during business hours, impacting productivity across multiple continents. Initial diagnostics by the Tier 1 support team suggest no commonality in specific user groups, locations, or phone models. The engineering team, after reviewing limited logs, suspects that the underlying network infrastructure might be introducing delays or packet loss that affects the timely delivery of SIP signaling messages, specifically during periods of high network utilization. This ambiguity, coupled with the critical nature of the service and the distributed impact, requires a nuanced approach to problem resolution. Which behavioral competency is most critical for the troubleshooting lead to effectively navigate this complex and evolving situation?

Accepted Answer

Adaptability and Flexibility

Question 16

A global enterprise\'s primary Cisco Unified Communications Manager cluster, responsible for all voice and video communications, has suddenly become unresponsive, leading to a complete service outage. Initial reports indicate a significant network disruption in the data center hosting the primary cluster, impacting its connectivity to critical backend services and potentially causing cascading failures. The organization\'s IT infrastructure includes a geographically dispersed CUCM cluster deployment with built-in redundancy. Considering the immediate need to restore critical communication services for thousands of users worldwide, what is the most effective immediate action to take to mitigate the outage and re-establish voice and video functionality?

Accepted Answer

Initiate a full restoration of the CUCM cluster using the most recent Disaster Recovery System (DRS) backup stored at a geographically distant disaster recovery site.

Question 17

A global enterprise\'s IP telephony infrastructure, managed by a Cisco Unified Communications Manager (CUCM) cluster, is experiencing widespread, intermittent audio degradation characterized by choppiness and dropped calls. Initial diagnostics indicate that network latency and packet loss are within acceptable thresholds for general data traffic, yet the voice quality suffers significantly. The support team has noted that the issue seems to correlate with periods of high network utilization and fluctuating bandwidth availability across different WAN links connecting branch offices to the central data center. Which of the following troubleshooting approaches best demonstrates adaptability and flexibility in addressing this complex, ambiguous scenario, moving beyond superficial checks to uncover the underlying behavioral dynamics of the system?

Accepted Answer

Re-evaluating and potentially recalibrating the adaptive jitter buffer settings and other RTP stream optimization parameters within CUCM, alongside a review of the network's QoS policy implementation to ensure it is dynamically and effectively prioritizing voice traffic under varying load conditions.

Question 18

Following a catastrophic failure rendering the Cisco Unified Communications Manager Publisher node entirely unresponsive, leading to a complete loss of call processing and endpoint registration across the enterprise voice infrastructure, what is the most direct and effective immediate action to restore full system functionality and operational control?

Accepted Answer

Initiate the promotion of a healthy Subscriber node to assume the Publisher role, thereby re-establishing the central control and database master for the cluster.

Question 19

A network administrator is troubleshooting an IP telephony deployment where a specific Media Gateway Control Protocol (MGCP) gateway is intermittently failing to process incoming call setup requests and is unresponsive to administrative commands, despite successfully transmitting periodic keep-alive messages. The administrator has confirmed basic network connectivity to the gateway. Which of the following actions is the most appropriate next step in diagnosing and resolving this issue?

Accepted Answer

Verify and correct the MGCP gateway's configuration parameters on the Call Agent.

Question 20

An enterprise\'s Cisco IP Telephony deployment is experiencing sporadic disruptions in video conferencing sessions. While participants can initiate and establish call signaling via SIP, the actual audio and video streams frequently fail to materialize or are severely degraded, leading to dropped connections. The network infrastructure is extensive, incorporating multiple routing domains, QoS policies configured for voice and video, and several stateful firewalls between the CUCM cluster and user endpoints. The issue is more pronounced with the recently introduced high-definition video service. What is the most effective troubleshooting methodology to isolate the root cause of these intermittent media stream failures?

Accepted Answer

Conduct comprehensive packet captures on CUCM servers, border routers, and firewalls, analyzing the captures for RTP packet loss, jitter, and stateful firewall session timeouts.

Question 21

A telecommunications engineer is tasked with troubleshooting a Cisco Unified Communications Manager (CUCM) cluster experiencing sporadic call drops and an inability for users to initiate new calls. Initial diagnostics have confirmed that individual endpoints are registered and basic network connectivity to the CUCM nodes is stable. The problem is not isolated to a specific time of day or user group, indicating a systemic issue within the call processing infrastructure. The engineer needs to determine the most effective immediate strategy to diagnose the root cause of these failures.

Accepted Answer

Reviewing Call Detail Records (CDRs) for patterns of failed call attempts and call termination reasons.

Question 22

During a severe, enterprise-wide IP telephony service outage that has rendered all voice and video communication channels inoperable across multiple continents, a troubleshooting team is struggling to gain control amidst a deluge of conflicting diagnostic data and urgent, often unverified, user reports. The immediate priority is service restoration, but the sheer volume of issues and the high-stakes environment demand more than just technical prowess. Which of the following behavioral competencies would be most critical for the lead troubleshooter to effectively navigate this crisis and guide the team towards resolution?

Accepted Answer

Leadership Potential, particularly decision-making under pressure and motivating team members

Question 23

A senior network engineer is tasked with resolving intermittent audio quality issues on a Cisco Unified Communications Manager (CUCM) deployment. Users report occasional clipping and robotic voice during calls, but standard network monitoring tools show no significant packet loss, jitter, or latency on the voice VLAN. The engineer has verified QoS policies are correctly applied and that the network infrastructure is not saturated. What underlying communication protocol aspect, if mishandled, would most likely cause such symptoms despite a seemingly healthy IP network path for the voice media itself?

Accepted Answer

Malformed or delayed Session Initiation Protocol (SIP) messages affecting call leg establishment and media stream negotiation.

Question 24

When a newly deployed Cisco IP Telephony system exhibits a 15% failure rate for calls originating from a remote branch office to the central site, while internal calls within both locations function reliably, and initial network diagnostics confirm stable WAN connectivity without excessive latency or packet loss, what is the most probable underlying technical cause for these intermittent call setup failures?

Accepted Answer

Inadequate marking of Session Initiation Protocol (SIP) signaling packets with appropriate Quality of Service (QoS) Class of Service (CoS) values for transit across the Wide Area Network (WAN).

Question 25

A remote branch office is experiencing intermittent failures when attempting to send faxes via their Cisco IP phones using the T.38 fax relay service. Users report that calls connect, but the fax transmission itself either fails completely or results in heavily distorted, unusable fax documents, often accompanied by audible artifacts on the audio channel during the attempt. Network monitoring tools indicate a sustained packet loss rate of approximately 15% on the WAN link connecting the branch to the central data center where the Cisco Unified Communications Manager (CUCM) resides. Which of the following is the most probable root cause for this issue?

Accepted Answer

Excessive packet loss on the WAN link disrupting the reliable transport of T.38 fax data packets.

Question 26

A network administrator is troubleshooting a Cisco Unified Communications Manager (CUCM) environment experiencing sporadic call failures and choppy audio on calls routed through a specific SIP trunk to an external provider. The troubleshooting team has confirmed that the CUCM servers are healthy, the internal network is stable, and the external provider\'s network is also reporting no issues. Initial packet captures reveal intermittent packet loss and jitter affecting the Real-time Transport Protocol (RTP) streams. Which of the following actions is most likely to resolve this issue by addressing a fundamental configuration aspect of the SIP trunk?

Accepted Answer

Re-verify and correct the transport protocol configuration for the SIP trunk, ensuring it is set to UDP for both SIP signaling and RTP media.

Question 27

A newly deployed Cisco Unified Communications Manager (CUCM) cluster is experiencing sporadic call drops and noticeable audio degradation for remote users connecting via VPN. Initial diagnostics have ruled out common CUCM configuration errors and endpoint hardware issues. The problem appears to be more prevalent during peak usage hours and exhibits no consistent failure pattern, making it difficult to pinpoint a single cause. The IT department suspects that the underlying network infrastructure, particularly the Quality of Service (QoS) implementation across the WAN and VPN tunnels, may be contributing to these intermittent issues.

What is the most critical area to investigate and potentially reconfigure to ensure reliable real-time media delivery for these remote users?

Accepted Answer

Verification and adjustment of Quality of Service (QoS) classification, marking, queuing, and policing mechanisms for UDP-based voice and video traffic across the entire network path, including VPN concentrators and WAN links.

Question 28

Anya, a network engineer supporting a large enterprise IP telephony deployment, is investigating persistent but intermittent complaints of choppy audio and dropped calls. She has confirmed that all Cisco IP phones are running the latest stable firmware, call detail records in Cisco Unified Communications Manager show no critical signaling errors during the affected periods, and basic Quality of Service (QoS) policies are applied at network ingress points. The issues are reported by users across various departments and locations, making a single endpoint or local network segment unlikely to be the sole cause. Anya needs to identify the most probable underlying network condition that could manifest as these symptoms, requiring her to pivot her troubleshooting strategy towards deeper network performance analysis.

Accepted Answer

Excessive buffering on intermediate network devices leading to increased queuing delay and jitter for voice packets.

Question 29

A network administrator is troubleshooting intermittent voice and video quality issues across a Cisco Unified Communications Manager (CUCM) cluster. Users report occasional choppy audio and pixelated video, with the problems appearing and disappearing without a clear pattern related to call volume or specific users. Initial investigation involved reviewing CUCM server logs, verifying QoS markings on phones and gateways, and confirming basic network reachability between endpoints and CUCM. These steps did not reveal any anomalies. The problem appears to be impacting multiple segments of the IP telephony network. What is the most logical next step to diagnose and resolve this persistent, yet sporadic, media quality degradation?

Accepted Answer

Conduct a thorough inspection of the physical network infrastructure, including checking for interface errors, duplex mismatches, port channel misconfigurations, and overall link utilization on critical network segments supporting voice and video traffic.

Question 30

A network administrator is tasked with resolving sporadic call quality degradation and dropped calls impacting a branch office connected via a dedicated MPLS WAN link. The issue is more pronounced during business hours when concurrent call volume increases. Initial investigation of Cisco Unified Communications Manager (CUCM) logs and call detail records (CDRs) shows no consistent signaling errors or device failures directly attributable to the CUCM cluster. The administrator suspects a network-related problem affecting the voice media path. Which of the following diagnostic steps would be most effective in pinpointing the root cause of this intermittent issue, considering the limited impact on signaling but significant impact on media?

Accepted Answer

Analyze WAN link utilization and Quality of Service (QoS) markings on intermediate routers for the branch office's IP address range, correlating with timestamps of reported call failures.

Troubleshooting Cisco IP Telephony & Video v1.0 Free Practice Test — 30 Questions

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