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Common CTI terms and their meaning

Computer Telephony Integration – CTI for short – refers to computer-assisted telephony, or the linking of telecommunications and information technology. This technical environment requires many technical terms and abbreviations. If you are not an IT expert and are interested in a CTI solution, we have compiled a list of the most common CTI terms and abbreviations, including brief explanations, to help you.

Common CTI Terms 

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  • ACD – Automatic Call Distribution = Telephone system

    An Automatic Call Distribution (ACD) system distributes the incoming calls from customers (“inbound telephony”) of a company to the individual employees in the customer service department. This can be an internal customer service department or an external service provider (call center). If no employee is currently free, the caller ends up in the queue.

    With the help of the ACD software, customer service managers define the rules for the distribution (“routing”) of customer inquiries. These include the “longest idle principle” – the caller who has been waiting the longest is put through to the employee whose last call was the longest ago. Alternatively, inquiries can also be distributed according to urgency/relevance or customer concerns. For distribution, an ACD then uses certain “skills” of the employees, i.e. abilities and qualifications such as language skills, technical knowledge, etc., and sorts the requests accordingly (“skill-based distribution”).

  • Agent

    An agent or call center agent is the employee in a call center who answers the calls or other contacts.

  • ANI – Automatic Number Identification

    Automatic Number Identification analyzes the caller’s phone number and can display corresponding information, such as the location from which the caller is calling, directly on the CTI client display. In combination with a CRM, the entire historical data of existing customers is displayed to the agent as soon as the call is answered.
  • BRI – Basic Rate Interface

    Designates a basic ISDN connection that is commonly used in Germany as a system or multi-device connection.

  • CSR – Customer Service Representative = Agent

    CSR is a synonym for a call center agent. This refers to call center employees who process service inquiries.
  • CSTA – Computer Supported Telecommunications Applications

    CSTA is a standard for processing and formatting telephony-related data. It is a part of a TAPI application (TAPI is explained below). The goal of CSTA is to standardize the data and make it easier to process for different platforms and programs.
  • DNIS – Dialed Number Identification Service

    Dialed Number Identification Service is an identification of which number the caller has dialed. This tells the agent who or what department the caller was originally trying to reach.
    This can be important for larger companies, as there is usually not only one telephone number and call forwarding occurs regularly. Especially call centers that serve different companies rely on this service. This allows, for example, a secretarial service where call centers answer phone calls on behalf of their clients.
    Thanks to DNIS, the call center agent learns that the caller has called for company X and can start the conversation with “Company X, good afternoon, what can I do for you”.
  • DTMF – Dual-Tone Multi-Frequency

    DTMF is a technical function where each key on the telephone keypad is assigned a different tone. If I call a call center and am asked to press a certain key to be forwarded to the right employee, the system recognizes my input in this way.
  • H.323

    H.323 is a standard recommended by the International Telecommunication Union ITU-T that defines protocols for the transmission of audio and video signals over a computer network.
  • ISDN – Integrated Services Digital Network

    ISDN is an international standard for a digital telecommunications network in which calls and data are switched over conventional copper telephone lines. Digitization allows better voice quality and higher data transmission rates than analog telephone networks.
  • ISP – Internet Service Provider

    An Internet Service Provider is a provider that enables users and companies to access the Internet. It often offers additional services such as telephony, TV and mobile services.
  • IVR – Interactive Voice Response

    VRU – Voice Response Unit

    For this purpose, keywords such as “order”, “question about invoices”, “technical problems” or “complaint” are offered in an upstream voice menu (Interactive Voice Response, IVR).
    By speaking the words offered or by pressing a key (DTMF), the user is directed to the correct service department.

  • JTAPI – Java Telephony API

    TAPI is the standard interface developed by Microsoft to link computers and telephones/telephone systems. JTAPI offers a cross-platform solution based on the Java programming language, which also works on Linux or Mac OS. In contrast to TAPI, which runs exclusively on Windows platforms. However, JTAPI has a low market penetration, therefore there is only little software using JTAPI compared to TAPI.

  • PBX – Private Branch Exchange

    PABX – Private Automatic Branch Exchange

    These terms stand for a subscriber exchange or also private branch exchange. All telephones of a company are connected to this device. Calls can be connected to each other. By adding ACD software, a fully automated telephone system can be made available.
  • PRI – Primary Multiplex Line

    A primary multiplex connection is a type of connection in ISDN technology with up to 30 call channels.
  • Screen Pop

    Screen Pop is the most expected feature when talking about CTI software. This is the software screen that opens automatically when an incoming call arrives. Here, according to the settings and available sources, all the important information about the caller is available for the agent. For link|that is our softphone.
  • TAPI – Telephony API

    TAPI is the standard interface developed by Microsoft to interconnect computers and telephones/telephone systems. TAPI also includes standards to pass all the details about a call to other software products such as a CRM and receive. Today TAPI is the most widely used standard for the interaction of telephony and software solutions. TAPI is only available for Windows computers and is not available for Linux or Mac OS.
  • TSP – TAPI Service Provider

    TSP is a subcomponent of the whole TAPI installation. It is a driver provided by the supplier of the telephone system, which is connected to the telephone system via LAN or USB and provides an interface for the actual TAPI driver.
  • TSAPI – Telephony Services API

    TSAPI was an alternative solution to Microsoft’s TAPI. It was produced by Novell and AT&T and offered not only clients for Windows, but also for Linux and Mac OS. Like JTAPI, this product could not establish itself as a standard. A real alternative, which is also compatible for Linux and Mac OS, is still missing.

Common CTI terms
The best CTI solution

We hope that this list of the most important terms will help you in your search for a suitable CTI solution. If you have any further questions or are interested in our solutions, please contact us.



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