Unified Communications Glossary of Terms

Learn to talk the talk!

Understanding the terms and acronyms used in Unified Communications can be a challenge for anyone in our industry. To help combat this, Stack8 has put together a Unified Communications Glossary of Terms.

Download the Glossary of Unified Communications Terms


Advanced Analytics – The integration of techniques to analyze and predict future outcomes based on current data trends. When applied to UC-generated information, such forward-looking analysis provides users with greater insight into customer relations and market moves to drive improvements in business practice.

Analog Telephone Adaptor (ATA) – a device for connecting traditional analog telephones, fax machines, and similar customer-premises devices to a digital phone system or a voice over IP telephony network.

Anywhere Worker – A mobile worker who may do their job anywhere and on any device and usually participates in virtual teams; also known as ‘the new way to work.’

Application Programming Interface (API) – An API allows two applications to communicate. It enables data to be seamlessly distributed to different applications on different devices in different locations, and then updated and manipulated in real time. They’re at the heart of cloud-based Unified Communications.

Asynchronous Transfer Mode (ATM) – a high-speed networking standard for voice and data. ATM’s are typically used for private long-distance networks. ATM utilizes fixed-sized cells rather than the variable-length packets Ethernet utilizes. This makes it easier to manage bandwidth; however, it is typically more expensive.

Auto Attendant – Is a virtual receptionist. Auto attendant allows callers to be automatically transferred to an extension without the intervention of an operator. They typically have a simple menu system and are customizable.

Availability – Availability is based on the probability of a hardware failure, which is obviously bad. Availability is determined by dividing the “mean time between failure” by the “mean time to repair” – in other words, how often things break down divided by how long it takes to fix them. “Five nines,” i.e. 99.999 percent, is the benchmark.


Business Phone – A phone designed with features that meet the needs of a business user and operating in a corporate office (or home office) environment; often in conjunction with a Unified Communications solution.

Business Phone Systems – Typically a centralized phone system that serves the voice telecommunication needs of enterprise users (or a public sector organization) within a single site or across multiple sites.

Business Continuity – See Disaster Recovery

Bring-your-own-device (BYOD) – Bring your own device refers to employees bringing personally owned mobile devices (laptops, tablets, and smart phones) to their workplace, and using those tools to access information and applications.


Call Admission Control (CAC) – To avoid network congestion and loss of quality for voice-over-IP calls across an IP-network by managing bandwidth allocation of services.

Caller ID – Caller ID is used to allow the called party to see the calling party’s name and telephone number before picking up the phone.

Chatbots – A Chatbot (short for chat robot) is a computer program that maintains a conversation with a user in natural language, understands the intent of the user, and sends a response based on business rules and data of the organization. For Unified Communications the possibilities for chatbots are limitless, they can be used to deal with many of the routine inquiries that typically make up the majority of service requests, as well as to simplify the user experience for customers. From a business perspective, chatbots are a natural evolution of the automated online assistants that are already fairly prevalent within these industries.

Cisco Agent Desktop (CAD) – A computer telephony integration (CTI) solution for single- and multi site IP-based contact centers. CAD helps increase agent and supervisor productivity, improve customer satisfaction, and reduce costs.

Cisco IP Communications (IPCC) – A comprehensive system of powerful, enterprise-class solutions-including IP telephony, unified communications, IP video and audio conferencing, and contact center.

Cisco Finesse – A browser based agent and supervisor desktop designed as a flexible one screen dashboard. It provides a collaborative experience uniting internal business functions with your customer service organization.

Cisco Group Management Protocol (CGMP) – Limits the forwarding of IP multicast packets to only those ports associated with IP multicast clients.

Cisco Packaged Contact Center Enterprise (PCCE) – A predesigned deployment model of Cisco Unified Contact Center Enterprise. With Packaged CCE, businesses can take advantage of a smaller hardware footprint and reduced time to install and configure.

Cisco Unified Communications Manager (CUCM) – An IP-based communications system integrating voice, video, data, and mobility products and applications. It enables more efficient, secure communications and can transform the way in which we communicate.

Cisco Unified Contact Center Express (UCCX) – Cisco Unified Contact Centre Express delivers a highly secure, available, virtual, and sophisticated customer interaction management solution for up to 400 agents.

Cisco Unified Contact Center Enterprise (UCCE) – Helps businesses and organizations deliver a connected digital experience. You can provide contextual, continuous, and high capability journeys for your customers. Fault tolerance helps ensure uninterrupted operation, and comprehensive reporting provides business intelligence to optimize your contact center.

Cisco Unified Intelligence Center (CUIC) – a web-based reporting application that provides real-time and historical reporting in an easy-to-use, wizard-based application for Cisco Customer Care products.

Cisco Supervisor Desktop (CSD) – A computer telephony integration solution for IP-based contact centers that is easy to deploy, configure, and manage. It provides supervisors with tools to increase productivity and improve customer satisfaction.

Click to Call – The ability to initiate a phone call from the contact list on your computer with the click of a mouse.

Cloud Communications – Voice and data communications over the Internet. All applications, switching, and storage, is hosted by a third-party outside the organization and accessed over the Internet. With Cloud communications, there is no significant capital expenditure for an in-house PBX system, and ongoing costs are more predictable than with a traditional premise-based solution.

Computer Telephony Integration (CTI) – Technology that enables integrated interaction on a telephone and a computer, such as click-to-call and screen pops.

Conference Calling –  A telephone call allowing multiple parties to join and participate in a dialog, or attend in a listen-only mode; used to conduct virtual meetings or connect with remote parties.

Consumerization – The emergence of the individual consumer as the primary driver of product and service design; originated from and is most commonly seen as a major IT trend e.g. the iPhone.

Contact Center – Centralized facility used for receiving or transmitting a large volume of interactions by telephone, email, web chat or social media.

Contact Centre – See above (alternate spelling).

Contact Center Wallboard – A Contact Center Wallboard is a software solution for calculating and displaying real-time customized data on large screens for use within a contact center environment

Conversations – A process by which data from customer behavior is used to help make key business decisions via market segmentation and predictive modeling; used in direct marketing, digital marketing, and CRM.

Customer Proprietary Network Information (CPNI) – This is the data collected about an individual users calls, such as time, date, duration and destination number of each call.

Customer Relationship Management (CRM) – Software that manages all aspects of an organization’s interactions customers and prospects. A unified communications solution can make a CRM system more accessible across an organization because it creates a heightened level of accessibility.



Data Center Model –An IT solution, system, or product (including UC, contact centers) designed as a server-based application in a hardened IT data center.

Denial of Service (DoS) – A DoS attack is an attempt to make a network unavailable to its intended users. DoS attacks is a favorite of hackers, criminals, and other trouble-causing types.

Direct Inward Dial (DID) – DID is used for call routing. Through DID, external callers are able to contact a user directly at their unique phone number.

Disaster Recovery (DR) – A set of policies and procedures intended to aid the restoration or continuation of vital technology systems following a natural or human-induced disaster. Redundant and geographically separated infrastructure and the ability to effectively work off-site are key provisions of disaster recovery plans.

Domain Name Server (DNS) – Maintains a directory of domain names and translate them to Internet Protocol (IP) addresses.


Endpoint – An endpoint is an IP telephone, a softphone, or an analog phone adapter device.

Extension – A standard extension us an individual user account on the Cloud associated with a physical endpoint by a two to six digit number. A Cloud extension is not associated with a physical endpoint, i.e., a voice mailbox, etc.


Find Me, Follow Me –Find me, follow me is used as a call-forwarding feature. It improves worker productivity and customer service by ensuring that every call reaches the right person, regardless of where he or she is working.

File Transfer Protocol (FTP) – A standard network protocol used for the transfer of computer files between a client and server on a computer network.

Firewall – A key security feature that you’ve almost certainly heard of. The firewall sits between two networks, such as a company’s internal network and the Internet, and prevents unauthorized people from accessing the internal network.

Fixed Mobile Convergence (FMC) – seamless flexibility and transition among fixed and mobile voice and data networks; including roaming between networks without user intervention or changing devices.

Frame Relay – A cost-efficient method of data transmission for intermittent traffic between LANs and between end-points in WANs. They’re less expensive than private leased lines because the carrier shares the frame relay bandwidth among many customers. This can have a negative impact on quality, and therefore requires detailed attention to engineering the solution.


High-Definition Video (HD video) – Video of higher resolution than the standard 480 lines of resolution; in video conferencing, HD video provides a greater level of immersion and an improved user experience.

Hosted Contact Center – Enabling a contact center to operate with technologies and capabilities that are operated by another party; typically located off-site in a third party data center.

Hosted VoIP – Hosted VoIP is when the hardware and PBX are hosted at an off-site location from where the VoIP telephone service is being used. Hosted VoIP provides them robust communications, cost certainty and future-proofs their business while eliminating significant capital expenditures for new in-house phone equipment.

Hybrid Cloud – A Cloud computing service that is composed of some combination of on-premise, private, public and community Cloud services, often from different service providers.


Instant Messaging (IM) – Real-time communication over the Internet using text-based messages. Popular consumer-facing examples include G-chat, AIM, and iMessage. IM is usually a central feature of unified communications.

Internet Telephony – Refers to the provisioning of communications services (voice, fax, SMS, voice-messaging) over the public Internet, rather than via the public switched telephone network (PSTN).

Interoperability –The ability for a communications technology to work seamlessly with complementary IT technologies, such as CRM, voice recording, market data systems, and traditional PBXs.

Internet Protocol-Private Branch Exchange (IP PBX) –   Is a business phone system that delivers voice or video over a data network using IP.

IP Phones – Uses voice over IP for placing and transmitting telephone calls over an IP network, instead of the traditional public switched telephone network (PSTN).

IP Telephony – More commonly referred to as Voice over IP (VoIP). IP telephony uses the IP network to carry voice communications, replacing the public switched telephone network.

Internet Telephony Service Provider (ITSP) – A company that provides VoIP services. ITSPs can be categorized into Interconnects, MSPs and Carriers.


JabberJabber is an all-in-one communication tool. It enables you to see your contacts’ availability and instantly communicate using video, instant messaging (IM), voice, voice messaging, and conferencing. This integrated application operates on premises and in cloud-based collaboration architectures.

Jitter – Jitter is caused by network congestion, which can create timing issues for when packets arrive, thereby contaminating voice calls and creating poor and unacceptable voice quality. This often manifests itself with “squawking” noises and other strange noises interrupting audio calls


Latency – Latency is the time it takes for a caller’s voice to be transported – packetized, sent over the network, depacketized and replayed – to the other person. Too much latency is bad, making for a disjointed conversation flow. Ideally, latency should not exceed 100 milliseconds. Geographical distance or a lower-speed network connection can cause latency issues.

Legacy System – Older, functional but obsolete computer or communications technology platforms, programs, or processes, still in use despite the availability of newer, more efficient and productive alternatives.

Local Area Network (LAN) – A computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building and has its network equipment and interconnects locally managed.

Location Service – The location service gets information from a registrar server about where a user is and provides that information to a SIP proxy server or redirect server. That way, a proxy server that receives a request to start a call with a user knows where to direct the request so that it reaches the user.

Lync to Cisco Jabber Migration Tool – The Microsoft Lync to Cisco Jabber Migration Tool is an application that enables users to migrate seamlessly provision all your end users with Cisco Jabber and import their buddy lists from Microsoft Lync instantly.


Managed IP Telephony Services – Hosted services. Typically, the end-customer business customer owns the IP PBX and related equipment, while the carrier or VAR provides management and maintenance for the phone system.

Managed UC Services – Managed UC Services is the practice of outsourcing certain or all day-to-day Unified Communications and telecom management responsibilities and functions to a provider as a strategic method for improving operations and lowering expenses.

Media Access Control Address (MAC / MAC Address) – Is a unique identifier assigned to network interfaces for communications at the data link layer of a network segment.

Mobile Device Management (MDM) – MDM software secures, monitors and manages mobile devices. It’s used to enforce data and configurations for mobile devices and includes the ability to lock or delete data from a lost or stolen mobile device.

Mobile Unified Communications (Mobile UC) – A mobile UC solution is seamlessly deploying telephony functions, voice, presence, chat, data, applications, and other technologies on a mobile device such as a smartphone or tablet.

Mobile Video – The ability to conduct video conferencing with remote parties through a mobile device.

Mobile VoIP – The ability to conduct an IP telephony call on a mobile device (in addition to using cellular carrier networks).

Mobility Router – allows users to make and receive calls from enterprise and personal mobile phone numbers by automatically selecting the best network (Wi-Fi or cellular) to optimize cost, call quality and battery life.


Network Address Translation (NAT) – A method of remapping one IP address space into another by modifying network address information in Internet Protocol (IP) datagram packet headers while they are in transit across a traffic routing device.

Network Address Translator Traversal (NAT Traversal) – A computer networking technique of establishing and maintaining Internet protocol connections across gateways that implement network address translation (NAT)


Origination & Termination – Origination refers to inbound calls or minutes from the PSTN. Termination refers to outbound calls or minutes from the PSTN.

Outbound Campaign ManagerOutbound Campaign Manager is a web tool that enables contact center agents and supervisors to manage their own outbound campaigns without needing full access to the Cisco Unified Contact Centre Express (UCCX) administration interface.


Packets – In VoIP, the voice is converted into data packets that are transmitted over the IP network and then reassembled into voice by an endpoint VoIP device.

Packet Loss – Packet loss occurs when one or more packets of data fail to reach their destination, resulting in a metallic sound or conversation dropouts. It can be caused by network congestion, distance, and poor line quality. Excessive packet loss is perceived as broken or missing communication.

Post Dial Delay (PDD) – The interval between dialing the last digit of the called number and hearing the ringback tone.

Presence Status – Is the ability to see a colleague’s presence status – whether they’re in the office or away from their desk.

Private Branch Exchange (PBX) – A term dating back to the days of switchboard operators referring to an organization’s telephone exchange.

Private Cloud – Is a Cloud solution operated solely for a single organization, whether managed internally or by a third-party and hosted internally or externally.

Public Cloud – A set of applications or resources based on the standard Cloud computing model, in which a service provider makes applications and storage available to the general public over the Internet.

Public Switched Telephone Network (PSTN) – The network of the public circuit-switched telephone lines, which allows any phone in the world to connect with any other phone.


Quality Monitoring – Refers to contact center software solutions that allow the real-time and post-call review of interactions between contact center personnel and their callers.

Quality of Service (QoS) – a measure of the overall performance of the network. It takes into consideration factors such as error rates, bandwidth, throughput, transmission delay, availability, and jitter.


Real-Time Transport Protocol (RTP) – An IP standard that for delivering audio and video over IP networks.

Redirect Server – When a SIP user is not on their network, a redirect server sends SIP requests to the network to which they may be connected. It maps a SIP address to an alternative SIP address and returns that address to the caller, who can then attempt to reach them at the alternative address.

Registrar Server – When a user switches on their device and connects to a network, effectively coming online and making themselves available to make and receive calls, there needs to be a mechanism for transmitting that information to other people. The user does that by authenticating and registering with their registrar server. In technical terms, they do that by sending a register request to the server. The server then stores the information it receives, such as the user’s IP address, so that others can find them. Typically, the server will also forward this information to be saved by location services and redirect servers.

Reliability – Reliability is determined by calculating how often the system fails compared to the percentage of the time that the system is available. The system should be available at least 99.999 percent of the time.


Salesforce CRM Connector – The Salesforce CRM Connector enables users to integrate Salesforce to their Cisco Unified Communications Manager seamlessly.

Service Level Agreement (SLA) – Part of a service contract that defines the level of service An SLA for voice quality typically includes call completion rate, PDD, and some measure of voice quality.

Session Border Controller (SBC) – Network device used to register, setup, control, and tear down VoIP multimedia communications sessions. An SBC ensures that only approved traffic passes into the heart of your business. An SBC also hides your internal network and your users IP addresses from the outside world, which provides additional security protection.

Session Initiation Protocol (SIP) – A widely-adopted, highly adaptable signaling protocol used for controlling communication sessions (e.g., voice and video calls) over IP. Other SIP-supported applications include instant messaging, video conferencing, presence information, streaming multimedia distribution, and file transfer. SIP offers cost-effective, open-standards connectivity for distributed UC and voice solutions for secondary sites.

SIP Address – A SIP address identifies and locates each user of a SIP-based VoIP system.

SIP Trunking – Is VoIP and streaming media service based on the Session Initiation Protocol by which Internet telephony service providers connect telephone services and unified communications to enterprises equipped with SIP-based private branch exchange (IP-PBX) and Unified Communications.

SIP Proxy Server – When a user agent attempts to connect with another user agent, it sends out a request, which usually goes to a local SIP proxy server. The proxy server acts as a proxy for the user agent, handling the request and sending it on to the proxy server belonging to the call recipient’s organization. Essentially, the proxy server acts as a call router, forwarding a call request to another proxy server closer to the recipient. A SIP proxy server can also be used to enforce corporate SIP policy. For example, it may forbid certain callers from using SIP to make calls outside the organization.

Social Collaboration – Refers to the technology tools that bring together the capabilities of social media and unified communications and collaboration into a unified solution, to improve team and organization effectiveness.

Social Enterprise – A general descriptor of organizations that use social media tools, both private/corporate and public, to enable and enhance their communication with employees, customers, prospects, partners and other stakeholders.

Soft Client – A PC or mobile software application providing UC or telephony over the Internet, replacing or supporting/enhancing a desktop phone or hard trading turret.

Softphone – A softphone is voice software that emulates a VoIP telephone on a Computer, Smartphone, or Tablet.

Software-Based Multi Point Control Unit (soft MCU) – A device commonly used to bridge video conferencing connections in a business environment.

Stack8 Moves, Adds and Changes Solution (SMACS)SMACS is a user provisioning tool for Cisco Unified Communications (UC) solutions. It is designed to ease businesses through the complexities of managing Moves, Adds, and Changes (MAC) for both users and devices

STUN Server – STUN stands for Session Traversal Utilities for Network Address Translation (NAT). A STUN server is designed to allow a SIP user to discover the public IP address and port number that their VoIP application uses. The purpose of this is to overcome the problem of effectively being cut off from traffic due to being connected to a network behind a NAT router.



Team Collaboration – The mutual sharing and joint development of ideas, content, and dialog using the tools of the ‘digital workplace’ to enable distributed team members to work together from where ever they are located.

Team Communication – The ability to enable team members together through communication of content and conversations in various forms and media, with the aim of achieving a common purpose or business goal.

Trunk Line – Trunk lines connect the PBX to public switched telephone network. With a Cloud-based solution, SIP trunks are used to make this connection.


UCCE (Cisco Unified Contact Center Enterprise) – Helps businesses and organizations deliver a connected digital experience. You can provide contextual, continuous, and high capability journeys for your customers. Fault tolerance helps ensure uninterrupted operation, and comprehensive reporting provides business intelligence to optimize your contact center.

UCCX (Cisco Unified Contact Center Express) – Cisco Unified Contact Centre Express delivers a highly secure, available, virtual, and sophisticated customer interaction management solution for up to 400 agents.

Unified Collaboration – Describes communication tools that bring all media (audio, video, content, text, etc.) together into a single, unified view, allowing the user to avoid application switching and toggling among various interfaces and tools.

Unified Communications  (UC) – Unified communications  is the integration of real-time communication services such as instant messaging (chat), presence information, telephony (including IP telephony), video conferencing, data sharing (including web connected electronic whiteboards interactive whiteboards), call control and speech recognition with non-real-time communication services such as unified messaging (integrated voicemail, e-mail, SMS and fax). UC is not necessarily a single product, but a set of products that provides a consistent unified user-interface across multiple devices and media types.

Unified Communications and Collaboration (UCC) – UCC integrates multiple communications channels to enable communication and collaboration across a company.

Unified Messaging – The integration of email, SMS, fax, voicemail, and video messaging into a single interface and made accessible from a variety of devices. It simplifies the user experience because all types of messages are stored in one place.

User Agent (UA) – This is the SIP software that sits on endpoints like IP phones, or runs in IP telephony software on a computer or mobile device, sitting between the end user and the network. A user agent can act as a client or a server, switching between the two roles as necessary.

User Agent Client – A user agent acts as a user agent client when it generates requests, such as when it starts the process of setting up a call to another person.

User Agent Server –  If user agents are on a small local network and know each others’ Uniform Resource Identifier (URI), then they can send and receive requests between them, and a call can be established without any further SIP infrastructure.


Video Calling – An interaction across a network that includes video capabilities in addition to voice.

Video Conferencing – Is the conduct of a video meeting by a set of telecommunication technologies (WebEx) which allow two or more parties or locations to communicate by simultaneous two-way video and audio transmissions.

Virtual LANs (VLANs) – Virtual LANs (VLANs) are used to “logically separate” devices and departments on the same Ethernet wire.

Virtual Private Network (VPN) – A VPN is a private network extended across a public network, i.e. the Internet. It enables the sharing of data across public networks in a typically more secure and functional way.

Virtualization – Virtualization allows companies to consolidate servers, increase operational flexibility and deliver higher application availability. Virtualization utilizes a group of servers in a way that allows the running multiple operating systems simultaneously on the same machine.

Voice Over IP (VoIP) – Voice calls over the IP data network. VoIP converts analog voice signals into digital data packets and supports real-time, two-way transmission of conversations using Internet Protocol.

VoIP Phones – See IP phone.

Voice Analysis – The systems and processes which analyze voice recordings, including those made through contact centers and trading stations, through pattern analysis, computational linguistics, phonetic indexing and semantic indexing.


Voice over WLAN (VoWLAN) – is the use of a wireless broadband network according to the IEEE 802.11 standards for voice conversation.


Web Collaboration – A service or solution that allows sharing of desktop content, files, video, text and white boarding among multiple users in real-time across the Internet.

Web Conferencing – A service or solution that allows broadcasting content over the Internet to multiple parties using a web browser, and sharing of desktop content, files, video, text and white boarding among multiple users in real-time across the Internet.

Web Real-Time Communication (WebRTC) – A standard drafted by the World Wide Web Consortium to enable browser-to-browser communication applications for voice calling, video chat, and P2P file sharing without plug-ins or additional software.


ATA – see Analog Telephone Adaptor

API – see Application Programming Interface

ATM – see Asynchronous Transfer Mode

BYOD – see Bring-your-own-device

CAC – see Call Admission Control

CGMP – see Cisco Group Management Protocol

CUCM – see Cisco Unified Communications Manager

CPNI – see Customer Proprietary Network Information

CRM – see Customer Relationship Management

CTI – see Computer Telephony Integration

DID – see Direct Inward Dial

DNS – see Domain Name Server

DoS – see Denial of Service

DR – see Disaster Recovery

FMC – see Fixed Mobile Convergence

FTP – see File Transfer Protocol

HD video – see High-Definition Video

IM – see Instant Messaging

IP PBX – see Internet Protocol-Private Branch Exchange

ITSP – see Internet Telephony Service Provider

LAN – see Local Area Network

MAC / MAC Address – see Media Access Control Address

MDM – see Mobile Device Management

Mobile UC – see Mobile Unified Communications

NAT – see Network Address Translation

NAT Traversal – see Network Address Translator Traversal

PBX – see Private Branch Exchange

PDD – see Post Dial Delay

PSTN – see Public Switched Telephone Network

QoS – see Quality of Service

SBC – see Session Border Controller

SIP – see Session Initiation Protocol

SLA – see Service Level Agreement

soft MCU – see Software-Based Multi Point Control Unit

SMACS – see Stack8 Moves, Adds and Changes Solution

UA – see User Agent

UC – see Unified Communications

UCC – see Unified Communications and Collaboration

UCCE – see Cisco Unified Contact Center Enterprise

UCCX – see Cisco Unified Contact Center Express

VLANs – see Virtual LANs

VoIP – see Voice Over IP

VoWLAN – see Voice over WLAN

VPN – see Virtual Private Network

WebRTC – see Web Real-Time Communication


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