CCNP Collaboration key terms

A group of CUCM nodes that share a single, replicated configuration database and provide call processing, device registration, and administrative services as one logical telephony system.

The publisher is the first node in a cluster and holds the read/write database copy; subscribers replicate that database and run call-processing services. Administrative writes normally occur against the publisher.

A CUCM configuration container that groups endpoints sharing settings such as region, location, date/time group, SRST reference, and calling search space, letting administrators configure many devices at once.

A CUCM setting that defines which audio and video codecs are permitted between devices in different regions, controlling compression but not total bandwidth consumption.

A CUCM call admission control construct that assigns a finite amount of audio and video bandwidth to the links between sites, blocking or rerouting calls that would exceed the limit.

A cluster-wide setting that determines whether endpoints and gateways must use authenticated, encrypted signaling and media; mixed mode enables a transition period where both secure and non-secure devices register.

A signed file containing certificates of the cluster's servers that is installed on endpoints so they can verify they are connecting to a legitimate CUCM and establish authenticated TLS sessions.

A CUCM service that issues, installs, and upgrades locally significant certificates on supported endpoints, enabling authenticated and encrypted connections without a third-party certificate authority.

A CUCM feature that imports users and their attributes from an external directory such as Microsoft Active Directory on a scheduled basis, so user accounts do not need to be created manually.

A CUCM feature that lets a user log in to a shared phone and download a personal device profile, applying their own directory number, speed dials, and services for that session only.

A CUCM feature that dynamically adjusts a roaming phone's device pool, region, location, and calling search space based on the IP subnet of the site where it is currently registered.

A router-based fallback service that lets phones at a branch register with a local gateway and place basic calls when the WAN link to the centralized CUCM cluster is lost.

Classifying voice media with DSCP EF (46) and call signaling with a lower assured-forwarding value so routers can prioritize real-time traffic during congestion.

A logical link between CUCM and another SIP system, such as a gateway or service provider, that carries calls and uses a SIP profile to control security, transport, and header behavior.

A voice gateway controlled almost entirely by CUCM using the Media Gateway Control Protocol, so dial plans and endpoint configuration reside on the call agent rather than the router.

A voice gateway that peers with CUCM using H.323 signaling; it keeps its own dial peers and configuration locally and provides a highly available alternative to MGCP control.

A lightweight Cisco protocol used between CUCM and endpoints such as analog adapters and older phones, carrying call control messages while media flows directly between devices.

A DHCP option that delivers a list of TFTP server addresses to IP phones, telling them where to download their configuration files and firmware before registration.

A CUCM service that stores and serves endpoint configuration files and firmware images; phones request these files at boot using the address learned from DHCP.

A Cisco IOS configuration object that matches inbound or outbound call legs by number pattern and defines how the call is routed, including destination, codec, and signaling parameters.

A router or CUBE configuration that matches a dialed number with a pattern and rewrites it using a replacement string, used for number normalization, stripping, and prefixing.

A media resource that terminates the media streams of two call legs, enabling features such as DTMF relay conversion, early media, or codec interoperability between differing endpoints.

A hardware or software media resource that converts one codec to another, allowing endpoints that share no common codec to communicate, for example G.729 to G.711.

G.711 is an uncompressed 64 kbps codec with excellent voice quality; G.729 compresses to 8 kbps and saves bandwidth at the cost of slightly lower quality and added processing delay.

The protocol that carries digitized voice and video streams between endpoints, providing sequence numbers, timestamps, and payload type identification over UDP.

A CUCM grouping of directory numbers that acts as a reachability scope; a number placed in a partition can only be dialed from a calling search space that includes that partition.

An ordered list of partitions assigned to a device or line that determines which dialed patterns and directory numbers that caller is permitted to reach.

A CUCM dial plan object that matches a dialed string and rewrites, blocks, or reroutes it before the call proceeds, commonly used to expand abbreviated internal dialing to full numbers.

A CUCM object that matches an external dialed number and points to a route list or gateway, defining which egress path a call takes outside the cluster.

A route group is an ordered set of gateways for a given path; a route list stacks route groups so CUCM tries the first choice and overflows to the next on failure.

A keepalive mechanism where CUCM periodically sends SIP OPTIONS requests to a trunk destination to verify reachability and mark the trunk in or out of service.

Early offer sends session description information in the initial INVITE so media can be set up immediately; delayed offer waits for the callee's response to learn its capabilities first.

The practice of converting dialed digits into a consistent E.164 format at the edge of each site so that calls route predictably between clusters, countries, and service providers.

An alphanumeric address formatted like an email address that identifies a user for URI dialing, allowing calls to be placed to a name rather than a numeric extension.

A CUCM feature that lets separate clusters exchange dial plan and user information so that numbers and URIs learned in one cluster can be dialed from another without manual replication.

A voice messaging application that provides voicemail, automated attendants, and message notification, integrating with CUCM over SIP or SCCP for message waiting indication.

A desktop and mobile client that delivers instant messaging, presence, voice, video, and voicemail access, registering to CUCM for calls and to IM and Presence for chat.

A cluster node that maintains user presence states and provides instant messaging, calendar-based status, and availability information to clients such as Jabber.

A hunt pilot is the number callers dial; its line group lists the agents' lines and the algorithm used to distribute calls among them until someone answers.

A feature that places an active call on hold against a park number so that any user who dials that number from another phone can retrieve the call.

Cisco Unified Border Element, a router-based session border controller that terminates and re-originates SIP signaling between networks, providing security, protocol normalization, and call admission control.

A device that terminates the signaling of an incoming call and generates a new call leg toward the destination, giving it full control over headers, media, and codec negotiation.

A paired traversal solution: the Expressway-C sits inside the trusted network next to CUCM, while the Expressway-E sits in the DMZ and handles encrypted connections from remote clients.

A Cisco feature that lets Jabber clients outside the network register to internal CUCM and IM and Presence services through the Expressway pair without a VPN client.

A framework using STUN and TURN servers to discover a working media path between endpoints behind firewalls and NAT, commonly used for remote Jabber media traversal.