CLCOR Practice Test 16 — 15 Questions

Question 1

Which TWO of the following are essential components of a Cisco network readiness assessment for collaboration?

Accepted Answer

Bandwidth capacity analysis. Bandwidth capacity analysis (A) is essential because Cisco collaboration services such as voice, video, and conferencing have strict per-call and per-stream bandwidth requirements, and the readiness assessment must confirm the WAN/LAN can carry the projected concurrent media load with adequate headroom. A QoS configuration audit (C) is equally essential because real-time collaboration traffic (RTP media, signaling) must be properly classified, marked, and queued (e.g., EF for voice, AF41 for video) to guarantee low latency, jitter, and packet loss across the network. Analyzing NTP Stratum levels (B) is not a core readiness component, since NTP accuracy matters for call detail records and certificates but stratum level itself is not a standard readiness metric. Verifying phone firmware versions (D) is a deployment/upgrade task rather than a network readiness assessment element. Checking IP address assignment (E) is a general design consideration, not one of the two essential readiness assessment components for collaboration.

Answer

Analyzing NTP Stratum levels

Answer

Verifying phone firmware versions

Answer

Checking IP address assignment

Question 2

Which TWO of the following are considered best practices for implementing QoS in a Cisco collaboration network?

Accepted Answer

Mark traffic as close to the source as possible. Option A is correct because Cisco QoS best practice is to classify and mark traffic as close to the source as possible, typically on the endpoint or the first-hop access switch, so that the DSCP value is preserved end-to-end and every downstream device can apply consistent per-hop behavior without re-classifying. Option D is correct because extending the trust boundary to the access layer switch allows that switch to trust the DSCP markings from Cisco IP phones and other endpoints, enforcing classification at the network edge rather than re-marking later. Option B is wrong because trusting all incoming traffic by default lets users or rogue devices set arbitrary DSCP values, which can abuse priority queues and break QoS guarantees. Option C is wrong because marking only at the WAN edge is too late—traffic has already traversed the LAN unclassified, and the WAN edge cannot reliably distinguish applications after congestion or encryption. Option E is wrong because disabling QoS removes classification, queuing, and policing, which degrades voice and video quality rather than improving performance.

Answer

Trust all incoming traffic by default

Answer

Only mark traffic at the WAN edge

Answer

Disable all QoS policies to improve performance

Question 3

Which THREE of the following items can be defined within a Device Pool?

Accepted Answer

Location. In Cisco Unified Communications Manager, a Device Pool is a template that groups common settings applied to devices such as IP phones and gateways. Option A (Location) is correct because the Device Pool specifies the Location, which enforces call admission control bandwidth limits between sites. Option B (Date/Time Group) is correct because the Device Pool defines the Date/Time Group that determines the time zone and date/time format displayed on the devices. Option D (Region) is correct because the Device Pool assigns the Region, which controls the codec selection for calls between devices in different regions. Option C (Translation Pattern) is not part of a Device Pool; translation patterns are configured under Call Routing > Translation Pattern and are applied during call routing, not as a device-level setting. Option E (Route Partition) is also not defined in a Device Pool; partitions are assigned to directory numbers, route patterns, and translation patterns via Calling Search Spaces, not to device pools.

Answer

Translation Pattern

Answer

Route Partition

Question 4

Which THREE components are part of the CUCM redundancy architecture?

Accepted Answer

Cisco Unified CM Group. In Cisco Unified Communications Manager (CUCM) redundancy architecture, the Cisco Unified CM Group (option A) is a correct component because it defines the ordered list of CUCM nodes that a device (phone, gateway, or trunk) registers with and falls back to, providing call-processing redundancy. Publisher and Subscriber nodes (option D) are correct because the cluster's database replication model relies on a Publisher providing the master configuration database and Subscribers receiving replicated copies, so if a node fails, others continue call processing. SRST Reference (option C) is correct because it points to a Survivable Remote Site Telephony gateway that provides fallback call processing for remote-site phones when WAN connectivity to the CUCM cluster is lost, which is a key element of the overall redundancy design. The TFTP service (option B) is not a redundancy component; it is a service used for endpoint configuration file download and firmware, and while it can run on multiple nodes, it is not itself part of the redundancy architecture. Cisco Unity Connection (option E) is a separate voicemail/messaging application, not a component of CUCM call-processing redundancy.

Answer

The TFTP service.

Answer

Cisco Unity Connection.

Question 5

When designing an NTP deployment for a Cisco Collaboration environment, what is the best practice for time synchronization across CUCM nodes?

Accepted Answer

Point all CUCM nodes to the same external NTP stratum 1 or 2 servers.. Cisco Collaboration best practice requires every CUCM node (publisher and subscribers) to synchronize directly with the same external, reliable NTP source — typically stratum 1 or 2 servers. This ensures consistent, accurate time across all nodes, which is critical for database replication, CDR timestamps, certificate validation, and log correlation. Pointing all nodes to the same external source avoids a single point of failure and prevents time drift that could break cluster operations.

Answer

Configure NTP only on the publisher node.

Answer

Point each CUCM node to a different NTP server for redundancy.

Answer

Use the publisher as the NTP server for all subscriber nodes.

Question 6

A Cisco IOS XE gateway is configured with two POTS dial peers that both match an inbound PSTN call on voice port 0/0/0. The first dial peer has preference 1 and destination pattern 9T; the second has preference 2 and destination pattern 9.... An engineer notices that calls are always routed using the second dial peer. What is the most likely explanation?

Accepted Answer

Inbound POTS dial-peer matching ignores the preference command; the dial peer with the longest match on the called number is selected.. Inbound POTS dial-peer selection uses the longest match on the called number from the destination-pattern, not the preference value. The pattern 9.... matches more digits than 9T, so it is chosen regardless of preference. Preference only acts as a tiebreaker when two dial peers have equal match lengths, which is not the case here.

Answer

The preference command only applies to outbound VoIP dial peers, so the second dial peer is chosen solely because it has a higher preference number.

Answer

The second dial peer has a lower preference value because the gateway interprets preference 2 as higher priority than preference 1.

Answer

The first dial peer is missing the incoming called-number command, so it cannot match inbound calls and the gateway falls back to the second dial peer.

Question 7

A collaboration engineer is designing a Webex Calling deployment for a company that requires all PSTN calls to egress through their existing on-premises Cisco Unified Border Element (CUBE) with a PRI circuit. The company wants to keep the PSTN gateway on-premises and use Webex Calling for internal and external calling. Which deployment option should the engineer choose?

Accepted Answer

Local Gateway. Local Gateway is the correct deployment option because it enables Webex Calling to route PSTN calls through an on-premises Cisco Unified Border Element (CUBE) or gateway, preserving the existing PRI circuit. This option is specifically designed for organizations that want to retain their on-premises PSTN connectivity while adopting Webex Calling for cloud-based call control and features.

Answer

Webex Calling with Cisco PSTN

Answer

Cloud Connected PSTN (CCP)

Answer

Webex Edge Audio

Question 8

A network engineer is configuring LLQ on a Cisco IOS router to protect voice traffic. The voice class is assigned a priority of 512 kbps. During periods of congestion, which mechanism ensures that voice packets are not delayed by lower-priority traffic?

Accepted Answer

The priority queue is serviced before other queues, and a policer drops packets that exceed the configured rate.. LLQ provides a strict priority queue that is serviced before other queues, ensuring voice packets experience minimal delay and jitter. The built-in policer enforces the configured bandwidth limit, dropping excess packets to prevent the priority queue from consuming all bandwidth and starving other traffic. This dual mechanism makes LLQ ideal for real-time voice.

Answer

Weighted fair queueing allocates bandwidth equally among all flows, including voice.

Answer

Traffic shaping buffers excess voice packets and sends them later.

Answer

The priority queue is serviced only when other queues are empty, but no policer is applied.

Question 9

A Cisco IP Phone 8845 registered to CUCM is not receiving its configuration file from the TFTP server after a factory reset. The phone has received its IP address via DHCP and can ping the TFTP server. Which option in the DHCP scope must be configured to allow the phone to locate the TFTP server?

Accepted Answer

Option 150. Cisco IP Phones rely on DHCP option 150 to learn the IP address of the TFTP server that hosts their configuration files. Without this option, the phone cannot proceed with provisioning. The other options serve different purposes: option 66 is a non-standard alternative, option 42 is for NTP, and option 3 is for the default gateway. Only option 150 directly addresses the phone's need to locate the TFTP server.

Answer

Option 42

Answer

Option 66

Answer

Option 3

Question 10

A Cisco Unified Communications Manager (CUCM) cluster is configured with a SIP trunk to a Cisco Unified Border Element (CUBE) for PSTN connectivity. Users report that outbound calls to a specific area code fail, but all other calls succeed. The CUCM route pattern for that area code is configured with a route list that includes the SIP trunk. The CUBE shows that it receives the INVITE but rejects it with a 488 Not Acceptable Here. Which CUCM configuration should be checked first to resolve this issue?

Accepted Answer

The region assigned to the SIP trunk, which defines the codec used for calls.. A 488 Not Acceptable Here response from CUBE indicates that the media description (SDP) in the INVITE is not acceptable. The region assigned to the SIP trunk in CUCM defines the codec that will be offered for calls traversing that trunk. If the region forces a codec that CUBE cannot support or that is not configured on the dial peer, CUBE rejects the call. Therefore, the region configuration should be verified first.

Answer

The SIP trunk's Inbound Calls > Significant Digits setting.

Answer

The route group's distribution algorithm.

Answer

The SIP trunk's Outbound Calls > Calling Party Selection setting.

Question 11

What is the first step to enable Webex Hybrid Services in a new organization?

Accepted Answer

Register the organization in Control Hub.. The first step to enable Webex Hybrid Services is to register the organization in Control Hub (A), because Control Hub is the management portal where the organization's Webex identity, licenses, and hybrid service configuration live. Without an organization registered in Control Hub, there is no anchor point for connecting on-premises components like Expressway-C or Expressway-E. Only after registration can you download the connector software, generate certificates, and configure hybrid services such as Hybrid Calendar, Hybrid Call Service, or Hybrid Message Service.

Answer

Purchase a PSTN plan.

Answer

Install the Expressway-C software.

Answer

Assign licenses to all users.

Question 12

A Cisco IOS gateway is connected to a WAN circuit where the physical line rate is 10 Mbps but the contracted CIR is only 4 Mbps. Voice quality suffers during bursts because the provider polices traffic above the CIR and drops excess packets. The engineer wants the gateway to smooth outbound traffic so the provider does not discard bursts. Which configuration element should be applied to the WAN interface?

Accepted Answer

A policy-map using the shape average 4000000 command applied outbound on the WAN interface.. When a provider polices at a CIR lower than the physical line rate, the enterprise side must pace its own transmissions. Traffic shaping with shape average set to the CIR buffers excess packets and releases them at a conforming rate, so the provider policer does not see bursts. Applying this outbound on the WAN interface protects voice and data from being discarded.

Answer

A class-map matching voice RTP ports with a set dscp ef action applied inbound on the WAN interface.

Answer

A policy-map using the police 4000000 command applied outbound on the WAN interface.

Answer

The bandwidth 4000 command under the physical WAN interface configuration.

Question 13

Which TWO of the following are valid deployment models for the Webex Calling PSTN connectivity? (Choose two)

Accepted Answer

Local Gateway.. Webex Calling supports two valid PSTN connectivity deployment models: Local Gateway (C) and Cloud Connected PSTN (E). Local Gateway is correct because it uses an on-premises gateway (such as a Cisco IOS XE router or CUBE) registered to Webex Calling via the Local Gateway registration process, allowing the enterprise to connect its own PSTN trunks to the Webex Calling cloud. Cloud Connected PSTN (CCP) is correct because it lets a certified CCP provider deliver PSTN service directly to Webex Calling through the Cisco Cloud Connectivity platform, with no on-premises gateway required. The remaining options are not valid Webex Calling PSTN deployment models: 'Webex Calling dedicated ISP' (A) is not a recognized model, 'Hybrid Cloud PSTN' (B) is not a Webex Calling PSTN option (hybrid refers to other deployment aspects), and 'Peer-to-Peer PSTN' (D) is not a supported architecture for Webex Calling PSTN connectivity.

Answer

Webex Calling dedicated ISP.

Answer

Hybrid Cloud PSTN.

Answer

Peer-to-Peer PSTN.

Question 14

Which service must be running for a phone to receive its configuration file?

Accepted Answer

Cisco TFTP. The Cisco TFTP service must be running for a phone to receive its configuration file. When a phone boots, it requests its configuration file (e.g., SEP<MAC>.cnf.xml) from the TFTP server, which is a core CUCM service. Without TFTP, the phone cannot download its configuration, firmware, or dial plan, and will fail to register.

Answer

Cisco Database Layer Monitor

Answer

Cisco CallManager

Answer

Cisco CTI Manager

Question 15

A network engineer is deploying a new branch office with a Cisco IOS XE gateway that connects to the service provider via a 100-Mbps Ethernet WAN link. The engineer needs to ensure that interactive voice traffic always receives priority treatment during congestion, while preventing non-real-time traffic from being starved. Which QoS mechanism should be configured on the WAN interface to guarantee strict priority for voice while still servicing other queues?

Accepted Answer

Configure a low-latency queue with the priority command inside a policy-map, and apply it to the WAN interface with service-policy output.. A low-latency queue created with the priority command inside a policy-map provides strict priority scheduling for voice traffic, ensuring that voice packets are always transmitted first when congestion occurs. The priority policer limits the amount of voice traffic that can enter the priority queue, preventing starvation of other queues. This mechanism is the standard way to guarantee voice quality on a WAN interface.

Answer

Enable traffic shaping on the WAN interface to smooth out bursts and reduce congestion for all traffic types.

Answer

Configure weighted random early detection (WRED) on the WAN interface to drop non-voice packets before congestion occurs.

Answer

Apply class-based weighted fair queueing (CBWFQ) with a bandwidth guarantee for the voice class, and rely on the scheduler to prioritize voice.