Glossary
A
access list A Unified CM setting that can applied to a remote destination to allow or block calls.
ad hoc The ability to join three parties into a conference without a prescheduled meeting and without requiring each of the three parties to dial in to a meeting.
alphanumeric uniform resource identifier (URI) dialing Dialing in which a call is placed using an alphanumeric URI in the form user@host.
alternate match A match for a dialed number that is a valid match but that is not a good match compared to the pattern that actually matched based on closest-match routing.
alternate number An alias for a directory number in an alternate format, such as an enterprise-specific globally unique number or the number in +E.164 format.
annunciator A media resource that plays recordings to users.
audio codec preference list An ordered list of codecs that determines Unified CM’s preference for which codecs to negotiate for a call.
B
back-to-back user agent (B2BUA) A device that has both UAC and UAS functionality and is capable of forwarding requests and processing them.
back-to-back user agent (B2BUA) A device that assumes the role of both an UAC and UAC in SIP sessions to interwork call legs.
bandwidth allocation An ELCAC configuration component that represents the amount of bandwidth allocated in the model for each type of traffic: audio, video, and immersive video. Deductions are taken based on the region configuration as well as the codecs that are actually negotiated for a call.
C
call admission control (CAC) A feature that allows an administrator to restrict the number of calls allowed between two network locations to ensure that network links are not oversubscribed, which could lead to potential voice and video quality issues.
call flow A high-level overview of the known devices and call legs involved with establishing multimedia sessions.
call leg A logical identifier for inbound or outbound call signaling on a given hop of a call flow.
call park A feature that allows a user to place a call on hold in such a way that the call can be retrieved from a phone other than the one that placed the call on hold by dialing a number associated with the parked call.
call park monitoring An advanced feature that is available on a limited set of IP phone models that allows the user to know when a call is still parked and to retrieve the call without having to remember the number where the call was parked.
call park reversion An event that occurs when a parked call has stayed parked too long and ends up reverting back to the user who parked the call.
call pickup A feature that allows a user to answer a ringing phone on behalf of another user.
calling search space An order list of partitions.
central office exchange (NXX) code A three-digit code that maps to the central office. A city may have more than one central office code, depending on the size of the city.
closest-match routing The process of searching for the best match, based on the match that results in the fewest possible matches.
Collaboration Solutions Analyzer (CSA) A Cisco tool that allows administrators to upload SDL trace files and post-process them to diagnose issues with calls.
Conference Now A feature that allows users to join a multi-party conference by dialing in through an IVR menu.
conferencing The ability for three or more participants to communicate on the same audio and/or video call.
country code An E.164-specific number that identifies phone numbers in a country; it may be up to three digits in length and may start with a plus (+).
D
Device Mobility A Unified CM feature that allows a user to take his or her device to a different site and inherit settings that are specific to the site the user is visiting.
Device Mobility group A means to link a device pool to a geographic area while being mindful of dialing requirements. Device Mobility groups are typically created on a per country basis. Globalized dial plans coupled with local route groups eliminate the need for Device Mobility groups.
Device Mobility information Information about which device pool is associated with a subnet.
Device Mobility mode A setting that determines whether a device is enabled to use Device Mobility.
Device Mobility–Related Information Device pool settings that remain constant when a user changes Device Mobility group and that allow user dialing habits to be maintained. This is typically dependent on whether a user has moved from one country to a different country as there are different dialing habits internationally. The key thing to understand is this setting helps allow users to dial numbers the way they are accustomed to dialing.
Dialed Number Analyzer (DNA) A tool that allows administrators to select a device and see what would happen if that device were to place a call to an administrator-provided string of digits without having to actually place the call.
digit analysis The core call processing function in the Cisco CallManager service running on a Unified CM cluster, which is responsible for matching digits with configured patterns and translations/digit manipulation.
digit discard instruction An instruction that discards specific parts of a number based on certain preestablished rules.
directed call park A feature that allows a user to park a call at a specific phone number instead of allowing the system to dynamically select the park number.
directed call pickup A feature that is similar to group call pickup in that it allows a user to answer a call ringing on another phone by pressing the Group Pickup softkey, but instead of dialing the pickup group number, the user dials the extension of the phone that is ringing.
directory number The number that appears on a phone line.
dual-tone multifrequency (DTMF) The combination of two tones, a high-frequency tone and low-frequency tone interleaved to represent a digit on the keypad (0–9, *, #) or a letter (A–D).
E–F
E.164 number An international phone number format that can be a maximum of 15 digits in length with the country code included.
+E.164 format A number format that identifies a calling or called user by formatting the number with the plus symbol (+) followed by the country code and then the national number to create a globally unique number on the public switched telephone network (PSTN).
effective path An ELCAC configuration component that is the end-to-end path with the least cumulative weight. As far as Unified CM is concerned, all traffic between two locations only traverses the effective path.
enbloc A type of calling that involves sending a string of digits all at once, as opposed to digit-by-digit transmission.
enhanced location call admission control (ELCAC) A static call admission control feature in Unified CM that allows administrators to model the network topology and assign bandwidth limits to links on that topology.
Extension Mobility A Unified CM feature that enables users to share phones while maintaining their own phone settings, including their directory numbers.
G
Global Dial Plan Replication (GDPR) A service that makes use of ILS to distribute numbers and patterns between Unified CM clusters.
group call pickup A feature that allows a phone to answer a call ringing on a phone in a different pickup group by pressing the Group Pickup button or softkey and then dialing the pickup group number where a phone is ringing.
H
H.225 A protocol that handles call setup and teardown between H.323 endpoints and is also responsible for peering with H.323 gatekeepers via the Registration Admission Status (RAS) protocol.
H.245 A peer protocol to H.225 that is used to negotiate the characteristics of the media session, such as media format, the method of DTMF relay, the media type (audio, video, fax, and so on), and the IP address/port pair for media.
H.323 A VoIP call control protocol from the ITU-T that allows for the establishment, maintenance, and teardown of multimedia sessions across H.323 endpoints.
hunt list An ordered list of line groups.
hunt pilot A number that can route calls to a hunt list for the purpose of distributing calls to phones registered to the cluster.
I–K
in-band DTMF relay The transmission of tones within the RTP (media) stream.
inbound dial peer The logical name for a dial peer that is associated to an inbound call leg. Configurations on this dial peer are leveraged to control signaling, media, and other aspects of the associated call leg.
Intelligent Session Control A Unified CM feature that allows calls to the remote destination number to be redirected to the enterprise phone.
interactive voice response (IVR) A media resource that plays prompts and collects input from the user.
Intercluster Lookup Service (ILS) A service that is responsible for replicating a variety of data between Unified CM clusters, including dial plan information with Global Dial Plan Replication.
international call A call that traverses international borders and utilizes E.164 number formatting.
Internet telephony service provider (ITSP) A service provider that offers a SIP trunk for connecting to the PSTN over public networks, such as the Internet.
IP Voice Media Streaming App service The Unified CM service that is responsible for Music on Hold, media termination point, annunciator, software conference, and interactive voice response media resources.
L
LHS The user portion of a URI in user@host format. Stands for left-hand side.
line group A grouping of directory numbers and rules that describe how calls should be distributed to a group.
link An ELCAC configuration component that interconnects locations and is used to define the bandwidth available between the locations. Links logically represent the amount of bandwidth available for different types of calls between two locations.
local call A call that is often within the same city and may not require an area code.
local route group A virtual route group that is matched with a real route group at the time a call is routed, based on the route group configured on the device pool of the calling device.
location An ELCAC configuration component that represents LAN or an aggregation point in a network. It could contain endpoints or simply serve as a transit location between links for WAN network modeling.
Location Bandwidth Manager (LBM) The service responsible for managing call admission control reservations for the enhanced location call admission control feature.
long-distance call A call that stays within the same country. Also known as a national call.
M
media resource A software or hardware component that provides media processing capabilities to Unified CM, such as a conference, media termination point, Music on Hold, interactive response, or annunciator services.
media resource group (MRG) An unordered list of media resources.
media resource group list (MRGL) An ordered list of media resource groups, ranked in priority order.
media termination point (MTP) A media resource that can be used to terminate media when a device involved in the call is not able to.
Meet-Me A multi-party conference call in which users dial in to a specific number to speak on the conference. This feature requires that an IP phone user initiate the conference with the Meet-Me button or softkey.
Mobile Connect An older name for Single Number Reach that may appear in documentation.
Move to Mobile A Unified CM feature that allows a user to move an active call to a remote destination via a single click of a softkey.
music on hold A media resource that plays live or prerecorded content to callers who have been placed on hold.
N
named telephony event (NTE) A payload format and specification for the transmission of DTMF tones within the media stream.
network hold The audio source heard when a system places a call on hold in order to invoke another feature, such as transfer, conference, or park.
numbering plan area (NPA) code A three-digit code that is usually mapped to a location such as a city. Often referred to simply as an area code.
O
OnNet Internal enterprise calls that remain on the enterprise network.
on-network (on-net) calling Calling in which calls route from the source to the destination entirely within the enterprise network or enterprise WAN.
OffNet External calls that leave the enterprise network.
off-network (off-net) calling Calling in which calls route from the enterprise to public networks such as the PSTN or Internet.
other call pickup A feature that allows administrators to associate multiple pickup groups so that a caller can answer a call ringing on a pickup group other than the pickup group of the phone without having to enter the pickup group number.
out-of-band (OOB) DTMF relay A DTMF transmission method that relies on the signaling channel to transmit DTMF information.
outbound dial peer The logical name for a dial peer that is used to create an outbound call leg. Configurations on this dial peer are used to control signaling, media, and other aspects of the new call leg.
P–Q
path An ELCAC configuration component that is a sequence of links and intermediate locations connecting a pair of locations. Unified CM calculates least-cost paths (lowest cumulative weight) from each location to all other locations and builds a map of the various paths. Only one effective path is used between any pair of locations.
partition A logical grouping of callable patterns.
pattern A string of digits and wildcards that represents a sequence of digits to match for call routing purposes.
physical location A means to link a device pool to a site while being mindful of site-specific settings such as date/time groups, media resources, and SRST references.
public switched telephone network (PSTN) An interconnected system of circuit-switched telephone networks operated by a variety of telephony operators.
R
Real-Time Monitoring Tool (RTMT) The primary method to get real-time diagnostic data from Unified CM, including SIP signaling information and downloading of trace files.
Real-Time Transport Control Protocol (RTCP) A protocol that provides media reception feedback for the related RTP stream.
Real-Time Transport Protocol (RTP) A framework for the end-to-end transport of voice and video IP networks using UDP.
regions A logical grouping of devices and the definition of maximum bit rates allowed for audio, video, and immersive video calls between groups.
remote destination The phone number of a device that is called when the remote destination profile’s associated line is called.
remote destination profile (RDP) A device that is created and linked to an end user and a specific line.
RHS The host portion of a URI in user@host format. Stands for right-hand side.
roaming device pool A device pool that is associated with a phone due to the phone being in a new subnet.
Roaming Sensitive settings Settings of a device pool that include region, date/time group, and many more. These settings are typically related to the local resources. For example, the date and time of the person is dependent on where they are. When they moved from one side of a country to another side of the same country, they time zone might change.
route group A group of one or more gateways or trunk devices that are logically grouped for the purpose of distributing calls to an external destination.
route list An ordered list of route groups used to route calls to an external system.
route pattern A pattern that allows an administrator to associate a called number with a route to an outbound gateway or trunk.
S
SDL trace file The primary trace file used when troubleshooting issues with Unified CM, which contains call signaling protocol–related messages as well as dial plan–related messages.
Session Description Protocol (SDP) A protocol designed to provide session details (such as the media types, media codec, and IP/port pair for media) and session metadata (such as the purpose of the session and the originator of the session) to participants.
Session Initiation Protocol (SIP) A communications protocol used for session setup, modification, and teardown between SIP user agents (UAs).
session target The Layer 3 addressing information of the next-hop device used by an outbound dial peer.
Single Number Reach (SNR) A Unified CM feature that allows a user to receive calls at home when someone calls the user’s desk phone.
static device pool A device pool that is configured on a device's configuration page.
subscriber number A four-digit extension that maps to a station.
T
tail-end hop off (TEHO) A process that intelligently routes calls to the PSTN over an IP network to a remote destination before sending the call to the PSTN to avoid paying toll charges for a call.
time period A period of time, either by hour, day, or date.
time schedule A grouping of time periods.
transcoder A media resource that converts one audio codec to another, such as from G.711 to G.729.
transfer target The party receiving the transfer request from the transferor. This participant will be connected to the transferee when the transfer is complete.
transferee The party being transferred to the transfer target. In a call this participant will be connected to the transfer target when the transfer is complete.
transferor The party initiating the transfer sequence and will be removed from the session when the transfer is complete.
transform mask A string of characters that can be used to manipulate a string of digits passed into the mask by either removing digits, replacing digits, or allowing digits from the original number to pass through to the result.
transformation A generic term that describes any of many different digit manipulations that can be performed on a digit string, such as transform masks, digit discard instructions, or prefixing digits.
transformation pattern A call routing element used to transform either the calling party number or called party number in various scenarios.
translation pattern A call routing element used to perform transformations on the calling party number and called party number prior to rerouting the call through digit analysis.
TranslatorX A third-party tool that can be used to parse SDL trace files and extract diagnostic data.
U–Z
urgent priority Indicates that a pattern that matches should be used immediately, even if potential matches exist.
user agent client (UAC) A SIP node that generates a request.
user agent server (UAS) A SIP node that processes a request and sends out at least one response.
user hold The audio source that is heard when a user presses the Hold button or softkey on his or her phone.
weight An ELCAC configuration component that provides the relative priority of a link in forming the effective path between any pair of locations. The effective path is the path used by Unified CM for the bandwidth calculations, and it has the least cumulative weight of all possible paths. Weight is used on a link to provide a cost for the effective path and is relevant only when there is more than one path between any two locations.
wildcard A special character in a pattern that matches more than one digit or character.