CLCOR Practice Test 13 — 15 Questions

Question 1

When troubleshooting a Hybrid Media Service node, which log file is most critical for determining if the media is being routed correctly to the cloud?

Accepted Answer

Hybrid Media Service logs. The Hybrid Media Service logs are the most critical for troubleshooting media routing issues because they contain detailed information about how the Hybrid Media Service node handles media streams, including routing decisions and errors. The correct answer is A.

Answer

Cisco Discovery Protocol logs

Answer

System event logs

Answer

Call processing logs

Question 2

In a Cisco collaboration design, you are tasked with identifying the DHCP Option required for Cisco IP Phones to discover the TFTP server address automatically. Which option is standard for this purpose?

Accepted Answer

Option 150. DHCP Option 150 is the Cisco-proprietary option that delivers a list of TFTP server IP addresses to Cisco IP Phones during DHCP scope configuration. Phones use this to locate the TFTP server, download their configuration XML and firmware, and register with CUCM. Option 66 is the standard (RFC 2132) TFTP server name option and can also work, but Option 150 is the Cisco-standard answer for IP phone TFTP discovery.

Answer

Option 66

Answer

Option 128

Answer

Option 43

Question 3

A user is unable to use their 'Speed Dial' button. What is the first thing you should verify?

Accepted Answer

The Phone Button Template.. A Speed Dial button is a programmable line key whose function is defined by the Phone Button Template assigned to the phone. If the template does not include a Speed Dial (or the button is not configured as Speed Dial), the button will not work regardless of DN or partition settings. Verifying the Phone Button Template is therefore the first step.

Answer

The device pool.

Answer

The user's password.

Answer

The DN's partition.

Question 4

When adding a new phone, what is the 'Device Name' parameter based on by default?

Accepted Answer

The MAC address of the phone.. When adding a new phone in Cisco Unified Communications Manager, the Device Name field is automatically populated with the phone's MAC address by default. This ensures each device has a unique identifier in the CUCM database, which is essential for configuration file delivery and registration.

Answer

The device pool name.

Answer

The extension number.

Answer

The user ID.

Question 5

Which TWO of the following are common audio codecs used in Cisco collaboration?

Accepted Answer

G.711. G.711 (option B) is a correct answer because it is a standard ITU-T narrowband audio codec (64 kbps PCM, using either A-law or mu-law companding) that is universally supported in Cisco collaboration endpoints and gateways for toll-quality voice. G.729 (option C) is also correct because it is a widely used ITU-T compressed audio codec (8 kbps CS-ACELP) commonly deployed in Cisco voice and collaboration environments to conserve bandwidth on WAN links. Option A (JPEG) is incorrect because it is a still-image compression standard, not an audio codec. Option D (H.264) is incorrect because it is a video compression standard used for video streams, not audio. Option E (MP3) is incorrect because, although it is an audio codec, it is a consumer music format and is not a standard codec used in Cisco collaboration call signaling/media negotiation.

Answer

JPEG

Answer

H.264

Answer

MP3

Question 6

Which THREE of the following are recommended steps when designing a secure signaling path between CUCM and a CUBE gateway?

Accepted Answer

Install and trust CA certificates. Option A is correct because securing the signaling path with TLS requires that both CUCM and CUBE trust each other's certificates, which means installing and trusting the CA certificates (or the specific device certificates) that signed the endpoints' certificates. Option B is correct because a SIP Trunk Security Profile on CUCM defines the security-related settings for the trunk, including device security mode (encrypted/authenticated), incoming/outgoing transport (TLS), and digest authentication, and it must be applied to the SIP trunk toward CUBE. Option D is correct because enabling TLS on the trunk encrypts SIP signaling between CUCM and CUBE, protecting the signaling path from eavesdropping and tampering. Option C is not a recommended step for securing the signaling path; digest authentication is a separate authentication mechanism and disabling it does not secure signaling, and in many designs it is left enabled or configured per policy. Option E is incorrect because H.323 Fast Start is an H.323 feature and is irrelevant to a SIP-based signaling path between CUCM and CUBE.

Answer

Disable SIP digest authentication

Answer

Enable H.323 Fast Start

Question 7

Which network condition is the most significant contributor to poor voice quality in a VoIP environment?

Accepted Answer

Jitter. Jitter—variation in packet arrival delay—is the most significant contributor to poor voice quality because VoIP codecs rely on a steady packet stream. Excessive jitter causes the jitter buffer to underrun or overflow, resulting in clipped, robotic, or dropped audio that is far more noticeable than raw latency.

Answer

Low CPU usage on the router

Answer

Static IP addresses

Answer

High bandwidth usage

Question 8

When configuring CUBE, why would you use a 'voice class uri' command?

Accepted Answer

To match SIP URI host. The 'voice class uri' command in CUBE is used to define a class of SIP URIs for matching purposes, typically to match the host portion of a SIP URI. This allows CUBE to categorize incoming or outgoing SIP requests based on the URI host, which can then be referenced in dial peers for routing or policy decisions. It is a key tool for URI-based routing and manipulation.

Answer

To define codec

Answer

To route by time

Answer

To match caller ID

Question 9

You are configuring DNS SRV records to support Jabber service discovery. Which domain format is correct for the _collab-edge._tls record?

Accepted Answer

_collab-edge._tls.example.com. DNS SRV records use the format _service._protocol.domain. For Jabber service discovery, the service is 'collab-edge' and the protocol is 'tls', so the correct record is _collab-edge._tls.example.com. This record is used by clients to locate the Expressway-E for Mobile and Remote Access (MRA) and is queried during the initial service discovery process.

Answer

_tls._collab-edge.example.com

Answer

collab-edge.example.com._tls

Answer

_collab-edge._tcp.example.com

Question 10

A Cisco IP Phone 8845 in the New York office registers to CUCM and downloads its configuration. The administrator notices that the phone uses a DHCP scope option to discover the TFTP server address. Which DHCP option is used by the phone for this purpose?

Accepted Answer

Option 150. Cisco IP phones use DHCP Option 150 to obtain a list of TFTP server addresses. This allows the phone to contact the correct TFTP server to download its configuration file and firmware. In a CUCM environment, Option 150 is the standard method for phone boot and registration, ensuring the device can locate the necessary files to become operational.

Answer

Option 42

Answer

Option 43

Answer

Option 66

Question 11

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

Accepted Answer

To match the dialed number. The primary function of a dial-peer destination-pattern is to match the dialed number (or digits) to determine which dial-peer to use for routing the call. It acts as a matching criterion for inbound and outbound dial-peers. The other options describe different dial-peer attributes.

Answer

To define the codec

Answer

To specify the gateway IP

Answer

To enable SIP

Question 12

Which THREE types of media resources can be managed by an MRGL?

Accepted Answer

Transcoder. A Media Resource Group List (MRGL) in Cisco Unified Communications Manager is used to prioritize and group media resources, and the three media resource types it can manage are transcoders (B), conference bridges (D), and Music on Hold (MoH) servers (E). Transcoder (B) is correct because MRGLs assign transcoders to devices for codec conversion between different codecs (e.g., G.711 and G.729). Conference Bridge (D) is correct because MRGLs control which conference bridge resources are used for ad hoc and Meet-Me conferences. Music on Hold (MoH) Server (E) is correct because MRGLs determine which MoH server(s) provide audio streams to callers on hold. Cisco Unity Connection (A) is a voicemail system, not a media resource managed by MRGLs, and SIP Trunk (C) is a signaling/transport interface, not a media resource type in an MRGL.

Answer

Cisco Unity Connection.

Answer

SIP Trunk.

Question 13

A collaboration engineer is designing a Cisco Unified Communications Manager (CUCM) cluster for a company with 5000 users. The cluster will have one publisher and three subscribers. The engineer must ensure that the design supports high availability and that IP phones can register and make calls even if one subscriber fails. Which two statements are true regarding CUCM redundancy and device registration? (Choose two.)

Accepted Answer

Each IP phone can be configured with a prioritized list of up to three CUCM servers for registration using a CUCM Group.. CUCM Groups provide a prioritized list of up to three CUCM servers for device registration. When a subscriber fails, phones automatically re-register to the next available server in their CUCM Group. The publisher should not be included in CUCM Groups for call processing to avoid overloading it. CUCM Groups are assigned via Device Pools, not directly to phones.

Answer

The publisher must be included in the CUCM Group to ensure that phones can register if all subscribers fail.

Answer

The maximum number of CUCM servers in a CUCM Group is five, allowing for greater redundancy.

Answer

CUCM Groups are assigned to phones directly on each phone configuration page, not via Device Pool.

Question 14

A network engineer is deploying Cisco Unified Border Element (CUBE) and must ensure that voice traffic is prioritized correctly across the enterprise network. Which command correctly maps the voice traffic DSCP value to the correct priority queue in a Cisco IOS-XE router?

Accepted Answer

class-map match-any VOICE; match dscp ef; policy-map VOICE-POLICY; class VOICE; priority 1000. The correct configuration is to match DSCP EF (46) in a class-map and apply the 'priority' command with a bandwidth value in the policy-map. This maps voice traffic to a low-latency priority queue, ensuring proper prioritization. The 'priority 1000' command creates a strict priority queue with a policed bandwidth of 1000 kbps, which is ideal for voice.

Answer

class-map match-any VOICE; match protocol sip; policy-map VOICE-POLICY; class VOICE; queue-limit 100

Answer

class-map match-all VOICE; match dscp cs4; policy-map VOICE-POLICY; class VOICE; bandwidth 1000

Answer

class-map match-any VOICE; match dscp ef; policy-map VOICE-POLICY; class VOICE; fair-queue

Question 15

Which TWO of the following fields are required when defining a Route Pattern?

Accepted Answer

Gateway/Route List. In Cisco Unified Communications Manager, a Route Pattern must specify the destination to match and where to send the matched calls, so option A (Gateway/Route List) is required to define the egress path for the pattern, and option E (Route Pattern String) is required to define the dialed digits or wildcard pattern that the route pattern matches. Options B (Codec), C (Bandwidth Limit), and D (Softkey Template) are not mandatory fields when creating a route pattern; codec and bandwidth are typically associated with regions/locations or device pools, and softkey templates apply to devices such as phones, not to route patterns themselves.

Answer

Codec

Answer

Bandwidth Limit

Answer

Softkey Template