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CCNP Collaboration practice questions

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First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

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Question 1Infrastructure and Design

Which node in a Cisco Unified Communications Manager cluster is the only one that writes to the cluster database?

  1. TFTP server
  2. Media resource node
  3. Publisher Correct answer.
  4. Subscriber

Explanation

The publisher is the database master for the cluster and is the only node that writes changes to the configuration database. Subscribers receive replicated read-only copies of that database.

Question 2Infrastructure and Design

Which protocol does Cisco Unified Communications Manager use to deliver phone configuration files to endpoints?

  1. SNMP
  2. HTTP
  3. FTP Correct answer.
  4. TFTP

Explanation

Cisco IP phones request their configuration files from the CUCM TFTP service during registration. FTP, HTTP, and SNMP are not used for that initial configuration file download.

Question 3Infrastructure and Design

A branch loses its WAN connection to the CUCM cluster. Which feature allows the local gateway to provide call processing for the branch phones?

  1. Cisco Unified SRST Correct answer.
  2. Cisco Unified Border Element
  3. Cisco Meeting Server
  4. Cisco Expressway-C

Explanation

Survivable Remote Site Telephony runs on the branch gateway and lets it take over call processing when the phones lose connectivity to CUCM. This keeps intra-branch and PSTN calling available during a WAN outage.

Question 4Infrastructure and Design

Which codec provides narrowband voice at 64 kbps?

  1. G.711 Correct answer.
  2. G.729
  3. Opus
  4. G.722

Explanation

G.711 is a narrowband codec that uses 64 kbps per call stream. G.722 is wideband, G.729 is compressed narrowband at 8 kbps, and Opus is a variable-rate codec.

Question 5Infrastructure and Design

Cisco Unified Border Element is best described as which type of device?

  1. Enterprise call-control cluster
  2. Unified voicemail platform
  3. Session border controller Correct answer.
  4. Conference bridge appliance

Explanation

Cisco Unified Border Element is a session border controller that interconnects SIP networks and provides border functions such as normalization, security, and policy enforcement. It does not provide call control, voicemail, or conferencing.

Question 6Infrastructure and Design

Which protocol allows Cisco Unified Communications Manager to control the ports on a Cisco IOS gateway?

  1. RTP
  2. H.323
  3. SIP
  4. MGCP Correct answer.

Explanation

MGCP is a client-server gateway control protocol in which CUCM acts as the call agent and directs the gateway's voice ports. H.323 and SIP are peer signaling protocols, and RTP carries media.

Question 7Infrastructure and Design

Which two Cisco products form the traversal pair used for Mobile and Remote Access with Jabber?

  1. CMS with TMS
  2. CUBE with SRST
  3. Expressway-C/E Correct answer.
  4. CUCM with IM&P

Explanation

Mobile and Remote Access uses an Expressway-C inside the enterprise and an Expressway-E in the DMZ to provide secure traversal for Jabber clients. CUCM and IM&P provide call control and presence but are not the traversal pair.

Question 8Infrastructure and Design

By default, which signaling protocol do current Cisco IP Phone models use to register with CUCM?

  1. SCCP
  2. MGCP
  3. H.323
  4. SIP Correct answer.

Explanation

Modern Cisco IP Phone models use SIP as their registration and call signaling protocol with CUCM. SCCP is supported on some models, while H.323 and MGCP are gateway or trunk protocols.

Question 9Infrastructure and Design

What is the maximum recommended round-trip latency between CUCM nodes in a cluster deployed over a WAN?

  1. 80 ms Correct answer.
  2. 300 ms
  3. 20 ms
  4. 150 ms

Explanation

Cisco supports clustering over a WAN when the round-trip latency between nodes does not exceed 80 ms. Higher latency can cause database replication and call-processing delays that affect cluster stability.

Question 10Infrastructure and Design

Which CUCM service must be activated to issue certificates to supported endpoints?

  1. Cisco CTIManager service
  2. CAPF service Correct answer.
  3. Cisco CallManager service
  4. Cisco TFTP service

Explanation

The Certificate Authority Proxy Function service acts as the certificate authority for endpoints that use certificates with CUCM. It issues and manages those endpoint certificates.

Question 11Infrastructure and Design

What is the primary role of a SIP trunk configured in CUCM?

  1. Connect to external SIP systems Correct answer.
  2. Provide inline power over Ethernet
  3. Store phone firmware and configuration
  4. Assign IP addresses to endpoint phones

Explanation

A SIP trunk is a logical interface that connects the CUCM cluster to external SIP systems such as gateways, CUBE, or another cluster. It carries signaling and media for calls that leave the cluster.

Question 12Infrastructure and Design

Which protocol supports PRI backhaul from a Cisco IOS gateway to CUCM?

  1. MGCP Correct answer.
  2. SCCP
  3. SIP
  4. H.323

Explanation

MGCP supports PRI backhaul, which sends ISDN Q.931 signaling messages from the gateway to CUCM while the gateway handles the lower-layer bearer channels. This lets CUCM manage PRI call routing centrally.

Question 13Infrastructure and Design

Which settings are commonly grouped by a CUCM device pool?

  1. Per-user PIN and credential policies
  2. Directory number forwarding rules
  3. Codes, regions, and time settings Correct answer.
  4. Individual phone button templates

Explanation

A device pool groups devices that share common settings such as region, location, date/time group, and SRST reference. It simplifies configuration by applying those settings consistently to many devices.

Question 14Infrastructure and Design

Which CUCM setting determines which codec is used for calls between two sites?

  1. Region Correct answer.
  2. SIP profile
  3. Location
  4. Device pool

Explanation

A region defines the codec that is used between devices in different regions. Locations then control how much bandwidth is allowed for those calls.

Question 15Infrastructure and Design

What does a CUCM location control?

  1. Bandwidth between locations Correct answer.
  2. Phone firmware version control
  3. Codec selection policy for endpoints
  4. User authentication method

Explanation

A location defines the amount of bandwidth available for calls to and from devices in that location. It is used for call admission control, while regions determine the codec used between sites.

Question 16Infrastructure and Design

Which media resource is required to convert G.729 to G.711 on a gateway?

  1. Media termination point
  2. Transcoder Correct answer.
  3. Annunciator
  4. Conference bridge

Explanation

A transcoder converts one codec to another, such as G.729 to G.711, so endpoints that do not share a codec can communicate. Conference bridges mix audio, MTPs handle certain media passthrough functions, and annunciators play recorded prompts.

Question 17Infrastructure and Design

Which certificate does CUCM use for HTTPS administrator access to its web pages?

  1. CallManager certificate
  2. Tomcat certificate Correct answer.
  3. CAPF certificate
  4. IPSEC certificate

Explanation

The Tomcat certificate secures HTTPS access to CUCM web administration and services. The CallManager certificate is used for other services such as SIP signaling, and CAPF manages endpoint certificates.

Question 18Infrastructure and Design

Which Expressway is placed in the DMZ for Mobile and Remote Access?

  1. Cisco Meeting Server
  2. Expressway-E Correct answer.
  3. Expressway-C
  4. Cisco TelePresence Management Suite

Explanation

The Expressway-E is the external edge server and is placed in the DMZ to accept inbound connections from remote Jabber clients. It pairs with the internal Expressway-C to complete the traversal path.

Question 19Infrastructure and Design

What is the purpose of a SIP profile in CUCM?

  1. Set phone background images
  2. Assign directory numbers to end users
  3. Define SIP timer/header behavior Correct answer.
  4. Configure DHCP scope options for phones

Explanation

A SIP profile contains SIP-specific parameters such as timers, headers, and early media behavior that are applied to a SIP trunk or line. It lets administrators tune SIP behavior without changing the underlying dial plan.

Question 20Infrastructure and Design

Which CUCM service monitors database replication health?

  1. Cisco CTIManager service
  2. Cisco CallManager service
  3. Database Layer Monitor Correct answer.
  4. Cisco TFTP service

Explanation

The Database Layer Monitor service tracks database replication status and reports replication failures in the cluster. Administrators use it to verify that subscribers are receiving database updates from the publisher.

Question 21Infrastructure and Design

What does a CUCM translation pattern do?

  1. Registers SIP trunks to the cluster
  2. Provides music on hold for calls
  3. Rewrites digits before routing Correct answer.
  4. Assigns IP addresses to gateways

Explanation

A translation pattern matches dialed digits and transforms them before the call is routed. It is commonly used to manipulate numbering, such as adding or removing prefixes.

Question 22Infrastructure and Design

Which signaling protocol is Cisco-proprietary and can be used by CUCM to control gateway ports?

  1. RTP
  2. SIP
  3. H.323
  4. SCCP Correct answer.

Explanation

SCCP is a Cisco-proprietary signaling protocol used between CUCM and certain endpoints and gateways. It allows CUCM to control functions on the gateway, although MGCP is more commonly associated with gateway port control.

Question 23Infrastructure and Design

Which CUCM object provides an ordered list of call-processing nodes for phone registration and failover?

  1. Device pool
  2. Location
  3. CM group Correct answer.
  4. Region

Explanation

A Cisco Unified Communications Manager group defines the ordered list of call-processing servers that devices use for registration and failover. A device pool then references that group to assign it to devices.

Question 24Infrastructure and Design

What is the maximum number of call-processing servers that can be configured in a CUCM group?

  1. 2
  2. 3 Correct answer.
  3. 4
  4. 1

Explanation

A CUCM group can contain up to three call-processing servers in priority order. Devices use the first available server in the group and move to the next server if the primary is unreachable.

Question 25Infrastructure and Design

Which deployment model places call control in the cloud while using local gateways for PSTN connectivity?

  1. On-premises CUCM
  2. Cisco Meeting Server
  3. Cisco Expressway
  4. Cisco Webex Calling Correct answer.

Explanation

Cisco Webex Calling is a cloud calling service where call control is hosted by Cisco while local gateways can provide PSTN connectivity. On-premises CUCM keeps call control in the enterprise, and CMS and Expressway serve different collaboration roles.

Question 26Infrastructure and Design

Which function does DHCP option 150 perform for a Cisco IP phone?

  1. It supplies the phone with the address of the NTP server.
  2. It supplies the phone with the URL of the directory server used for LDAP authentication.
  3. It supplies the phone with a list of TFTP server addresses. Correct answer.
  4. It supplies the phone with the voice VLAN identifier.

Explanation

DHCP option 150 carries a list of TFTP server addresses that the phone contacts to download its configuration and firmware. Option 66 can carry a single TFTP name, but option 150 supports more than one address.

Question 27Infrastructure and Design

Which DSCP value does Cisco recommend for marking voice bearer (RTP) traffic in the QoS baseline?

  1. AF41 (34)
  2. AF31 (26)
  3. CS3 (24)
  4. EF (46) Correct answer.

Explanation

The voice bearer stream is marked Expedited Forwarding (DSCP 46) so each hop can place it in the low-latency priority queue. Interactive video uses AF41, call signaling uses AF31, and broadcast video uses CS3.

Question 28Infrastructure and Design

What does Survivable Remote Site Telephony provide during a WAN outage between a branch and its CUCM cluster?

  1. It lets branch phones register to the local router and keep making calls. Correct answer.
  2. It automatically reroutes calls through the PSTN gateway at the branch during the outage.
  3. It converts G.729 calls to G.711 for traffic that leaves the branch.
  4. It keeps the branch phones registered to a subscriber at another site.

Explanation

SRST runs on the branch router and offers a limited feature set when phones lose connectivity to the cluster. Phones register to the SRST router through the SRST reference configured on the device pool.

Question 29Infrastructure and Design

What is the maximum per-port power that IEEE 802.3af Power over Ethernet can deliver to a powered device?

  1. 7.0 W
  2. 30.0 W
  3. 4.5 W
  4. 15.4 W Correct answer.

Explanation

802.3af allows up to 15.4 W at the switch port, which leaves roughly 12.95 W at the powered device after cable loss. The newer 802.3at (PoE+) standard raises the port budget to 30 W.

Question 30Infrastructure and Design

Which LLDP-MED TLV conveys the voice VLAN ID and the Layer 2 and Layer 3 QoS values from the switch to an IP phone?

  1. Network policy TLV Correct answer.
  2. Power via MDI TLV
  3. Location identification TLV
  4. Inventory management TLV

Explanation

The network policy TLV tells the endpoint which VLAN to use along with the 802.1p CoS and DSCP values to apply to voice traffic. The phone then tags its voice frames accordingly.

Question 31Infrastructure and Design

Which line group distribution algorithm sends a new call to the member that has been idle for the longest time?

  1. Circular
  2. Top down
  3. Broadcast
  4. Longest idle Correct answer.

Explanation

Longest idle tracks when each member last handled a call and selects the member that has been idle the longest, which spreads load evenly. Top down always starts at the first member, while circular moves through the list in order.

Question 32Infrastructure and Design

Why must consistent NTP time synchronization be established across all nodes of a CUCM cluster?

  1. To avoid certificate and replication failures caused by clock skew. Correct answer.
  2. To keep the phone firmware load consistent across the cluster.
  3. To align ring cadence between the PSTN gateway and the phones.
  4. To allow subscribers to register with the publisher.

Explanation

CUCM relies on certificates for intra-cluster and endpoint security, and replication, logs, and CDRs all depend on matching timestamps. Clock skew beyond a small tolerance breaks certificate validation and can disrupt replication.

Question 33Infrastructure and Design

What does enabling SIP OPTIONS ping on a CUCM SIP trunk accomplish?

  1. It compresses SIP headers to save WAN bandwidth.
  2. It registers the trunk endpoints with the remote SIP registrar.
  3. It forces every call on the trunk to use early offer with an inserted MTP.
  4. It probes the destination so trunk status reflects real reachability. Correct answer.

Explanation

With OPTIONS ping enabled, CUCM periodically sends SIP OPTIONS requests to the far end and marks the trunk in service or out of service based on the replies. This detects failures faster and more accurately than waiting for a call attempt to fail.

Question 34Infrastructure and Design

After a Cisco IP phone has obtained an IP address and a TFTP server, which file does it request to obtain its own device-specific configuration?

  1. RingList.xml
  2. SEP<MAC>.cnf.xml Correct answer.
  3. SEP<MAC>.sbn
  4. XMLDefault.cnf.xml

Explanation

A phone builds its configuration file name from its own MAC address, requesting SEP followed by the MAC address with the .cnf.xml suffix. XMLDefault.cnf.xml is only a fallback used when the device-specific file does not exist.

Question 35Infrastructure and Design

A caller's search space contains partition A with the pattern 1XXX and partition B with the pattern 12XX. The caller dials 1234. Which pattern does CUCM use?

  1. 12XX, because it is the more specific match. Correct answer.
  2. Neither, because the overlapping patterns cause the call to be rejected.
  3. Both, and the call is forked to a destination in each partition.
  4. 1XXX, because it appears in the search space first.

Explanation

CUCM evaluates every partition reachable from the calling search space and selects the closest match to the dialed digits; a more specific pattern beats a less specific one. Partition order only breaks ties between patterns that match equally well.

Question 36Infrastructure and Design

Which media resource plays prerecorded announcements, such as a disconnected-number message, to callers?

  1. Conference bridge
  2. Annunciator Correct answer.
  3. Media termination point
  4. Transcoder

Explanation

The annunciator streams prerecorded .wav announcements to callers for conditions such as disconnected numbers or unanswered queues. It can run as a CUCM service or on a supported gateway.

Question 37Infrastructure and Design

Why is multicast MoH preferred over unicast MoH in a large campus?

  1. It removes the need for an MoH server in the cluster.
  2. It encrypts the music stream separately for each listener on the call.
  3. It sends one stream to many listeners, cutting server bandwidth. Correct answer.
  4. It keeps MoH playing during SRST fallback.

Explanation

With multicast MoH the server sends a single stream to a multicast group and the network replicates it to listeners, so server and WAN usage do not grow with the number of held calls. Unicast MoH needs a separate stream for every held call.

Question 38Infrastructure and Design

A call between two sites is rejected because the configured location bandwidth is exhausted. Which CUCM feature reroutes the call over the PSTN to an alternate number configured on the line?

  1. SIP OPTIONS ping on the inter-site trunk
  2. Automated Alternate Routing Correct answer.
  3. Call forward all on the called line
  4. Tail-end hop-off, routing the call out through a remote site gateway

Explanation

Automated Alternate Routing uses the AAR group on the device and the AAR calling search space to retry a call that locations-based admission control denied, dialing the alternate number configured on the line. That alternate number is usually the destination's PSTN DID.

Question 39Infrastructure and Design

In a cluster with one publisher and two subscribers, the publisher fails. Which function becomes unavailable while it is down?

  1. Registration of IP phones that are already configured in the database.
  2. Access to the voicemail system for users at the remote sites.
  3. Call processing for phones registered to the subscribers.
  4. Configuration changes and generation of new phone config files. Correct answer.

Explanation

Subscribers keep a read-only replica of the database and continue to register phones and process calls with the existing configuration. Only the publisher accepts database writes, so configuration changes and newly generated configuration files must wait for it to return.

Question 40Infrastructure and Design

A location pair is limited to 768 kbps of audio bandwidth between two sites, and each G.711 call consumes the default 80 kbps. Approximately how many simultaneous calls are admitted?

  1. 8
  2. 6
  3. 12
  4. 9 Correct answer.

Explanation

Admission control divides the available bandwidth by the per-call bandwidth: 768 divided by 80 is 9.6, so nine calls are admitted and the tenth is denied. Reporting the result as approximately nine accounts for the fractional remainder.

Question 41Protocols and Endpoints

Which SIP request is used to terminate a session that has already been established?

  1. CANCEL
  2. ACK
  3. BYE Correct answer.
  4. OPTIONS

Explanation

BYE is sent inside an established dialog to end the session, and the peer responds with 200 OK. CANCEL only applies to a request that has not yet received a final response, so it cannot tear down a connected call.

Question 42Protocols and Endpoints

By default, Cisco SCCP phones register with Cisco Unified Communications Manager over which TCP port?

  1. 2428
  2. 1720
  3. 5060
  4. 2000 Correct answer.

Explanation

Skinny Client Control Protocol uses TCP port 2000 for the signaling connection between the phone and Unified CM. Port 5060 is SIP, 2428 is MGCP, and 1720 is H.225 call signaling.

Question 43Protocols and Endpoints

Which static RTP payload type number corresponds to the G.729 codec?

  1. 0
  2. 18 Correct answer.
  3. 8
  4. 101

Explanation

The RTP audio/video profile statically assigns payload type 18 to G.729. Payload type 0 is G.711 mu-law and 8 is G.711 A-law, while 101 is a commonly used dynamic type for telephone events.

Question 44Protocols and Endpoints

Which protocol provides encryption, message authentication, and replay protection for RTP media streams?

  1. IPsec AH
  2. SRTP Correct answer.
  3. RTCP
  4. TLS

Explanation

Secure RTP wraps the RTP payload with encryption plus an authentication tag and an index that prevents replay. It is the standard way to protect voice and video bearers end to end.

Question 45Protocols and Endpoints

In H.323, which protocol carries call setup and Q.931 messages between endpoints?

  1. RAS registration and admission
  2. H.225.0 call signaling Correct answer.
  3. H.245 capability exchange
  4. RTP media transport

Explanation

H.225.0 call signaling transports Q.931 call control messages used to establish and tear down H.323 calls. H.245 handles capabilities, and RAS handles gatekeeper interactions.

Question 46Protocols and Endpoints

Which DSCP value is the recommended marking for voice bearer traffic?

  1. AF41 (34)
  2. CS3 (24)
  3. AF31 (26)
  4. EF (46) Correct answer.

Explanation

Expedited Forwarding (DSCP 46) is the standard marking for voice bearer packets so that they receive low-latency, low-loss treatment. AF41 is typically used for interactive video and CS3 for call signaling.

Question 47Protocols and Endpoints

Which DTMF method transports digits inside RTP using a named telephone-event payload type?

  1. KPML subscription/notify
  2. RFC 4733 Correct answer.
  3. SIP INFO signaling
  4. In-band dual-tone audio

Explanation

RFC 4733 (formerly RFC 2833) sends DTMF as distinct RTP event packets with a named telephone-event payload type instead of audible tones. This survives compression and low-bit-rate codecs that would distort in-band tones.

Question 48Protocols and Endpoints

Which file does a Cisco SCCP phone request from the TFTP server to obtain its own device-specific configuration?

  1. XMLDefault.cnf.xml
  2. jabber-config.xml
  3. SEP<MAC>.cnf.xml Correct answer.
  4. dialplan.xml

Explanation

A Cisco SCCP phone builds its configuration file name from the prefix SEP plus its MAC address, for example SEP001122334455.cnf.xml. That file holds its device pool, button template, and Unified CM server list.

Question 49Protocols and Endpoints

A SIP phone sends a REGISTER and receives a 401 Unauthorized response. What is the correct next action?

  1. Resend the REGISTER without a Contact header field
  2. Fall back to SCCP registration with the call agent
  3. Send a CANCEL to abort the pending registration
  4. Resend REGISTER with an Authorization header Correct answer.

Explanation

A 401 challenge means the registrar requires digest credentials for the realm it advertised. The endpoint recomputes the request with the correct nonce and resubmits it carrying an Authorization header.

Question 50Protocols and Endpoints

In an SDP body, which line specifies the media type, transport port, and transport protocol?

  1. m= Correct answer.
  2. a=
  3. o=
  4. c=

Explanation

The m= line defines each media stream with its type, port, transport protocol, and payload type list. The c= line carries the connection address and the a= lines carry attributes.