The CTI Client Professional includes an integrated SIP SoftPhone.

So you only need a headset to use your PC as a simple SIP Softphone in conjunction with a VoIP provider or a local VoIP system.


The integrated SIP softphone supports the following functions:

  • Dial, hang up, accept call, hold, consultation, transfer, pickup
  • DTMF dialing
  • Audio-Codecs: G.711 (A-Law and U-Law)
  • DND
  • Busy Lamp by SIP-SUBSCRIBE

Conditionally supported functions:

Unsupported features:

  • voice encryption


Under [Options > Phone Dialog (TAPI Device) > Select > VoIP] select the "SIP SoftPhone".
A new SIP registration is to configure via the button [Device Configuration].

Later you reach the configuration via: [Options > PhoneDialog (TAPI Device) > Driver Configuration > Edit].

Audio Settings

You can configure the audio-settings via: [Options > Audio...]

  • Here you determine the sound devices for microphone and Headset loudspeaker as well as their volume.
  • Under "Extended Settings..." you can:
    • set the ring tone volume and let signal phone calls if necessary over a second sound device (e.g., speaker),
    • declare own WAVE files for the ring tones.

Wireless headsets

The CTI Client supports special wireless headsets, so that a call can be accepted and hung up via a button on the headset (in principle).

The configuration is made via [Options > Audio > Advanced Settings].

Unfortunately, it can not be guaranteed that call-answer / hang-up using the headset button will work with all models of the listed manufacturers.
And even with the tested models, there were problems on individual Windows PCs.

The headsets of the following manufacturers are supported:

  • Jabra / GN Netcom
    • Tested models: "Jabra PRO 930", "Jabra EVOLVE 65 UC" and "Jabra Stealth UC MS".
  • Plantronics
    • Tested models: "Savi Office", "CS60"
Hints to Jabra Headsets
  • The "Jabra Direct" software must be installed on the PC.
  • If the headset is connected to the PC, the Jabra Direct software should show "Device ready for use".
  • In the Jabra Direct software, click "Device Settings" and set "Preferred softphone" to "Standard softphone".(see screenshot)
  • In the CTI Client, select "Jabra" under [Options > Audio > Advanced settings > Special wireless headset].
    A click on the "Test" button should display "OK".
  • Now you can try to answer a call using the headset key.
Hints to Plantronics Headsets
  • The "Plantronics Hub" software must be installed on the PC. On the download page, supported models are listed.
  • If the headset is connected to the PC, this should be displayed in the Plantronics Hub software on the "Info" tab.
  • In the Plantronics Hub software, click [Settings > Softphones]. You can set the "Target Softphone" to "None".
  • In the CTI Client, select "Plantronics" under [Options > Audio > Advanced Settings > Special wireless headset].
    A click on the "Test" button should display "OK".
  • Now you can try to answer a call using the headset key.
  • Note to Savi Office:
    • In the case of an incoming call, the LED "PC/VOIP" should be switched on at the base station. It may be necessary to specify "PC" as the default in the Plantronics Control settings.
    • The call signaling and call answer only work if the headset is in idle mode. If the headset is taken from the base (without a call), it will be automatically activated. Then press the button twice on the headset, so that it goes again Idle.
Troubleshooting (Jabra/Plantronics)

If call answer by the headset key does not work:

  • Restart the computer.
  • Try to connect the headset to a different USB port.
  • Try the headset on another computer.

If the activation of the audio connection to the headset blocks for several seconds:

  • Restart the computer/laptop.

SIP SoftPhone in a terminal session

Can the CTI Client be used as a SIP-Softphone in a terminal session?

In principle, yes. Under the RDP settings / Local resources, the audio recording and playback is to be activated. You would have to test whether the audio quality meets your requirements. If there are unacceptable voice delays or audio crashes, switching to physical SIP phones is recommended, or you can test the combination of Zoiper + CTI Client.

Notes for some functions


If you are in a call and click on a speed dial key, the active call is automatically held and a consultation call is established. Further possibilities for initiating a consultation ...


For the function "Pickup" the corresponding pickup code of your telephone system is to be entered under:
[Options > PhoneDialog (TAPI Device) > Driver Configuration > Edit > SIP Service Provider > Settings > Pickup].

  • For a pickup group, you may only need to enter the pickup code. Frequently * 8 is used for pickup.

  • For direct pickup, the extension number must also be dialed in (eg * 8234). In this case, the hook is to be set at: "+ Phone number".
    The "Direct Pickup" is done via the right-click menu of the speed dial buttons or via the pickup tool button from the PhoneDialog.

Conference Call

The SIP SoftPhone component can not switch conferences by itself. Under [Options > PhoneDialog (TAPI Device) > Driver Configuration > Edit] you can select an alternative conference mode:

  • personal conference room: If you have a personal conference room in the telephone system, you can enter the conference room number here.
  • 3-Party-Conference via DTMF *3: Customers of "Deutsche Telefon Standard AG" can use this mode. The conference function is also to be activated by "Deutsche Telefon Standard AG". 
    Hint: Under the [SIP Service Provider > Settings], the DTMF mode should be set to "RFC 2833".
  • A prerequisite for switching a three-way conference is that you have already set up a consultation call (a held call and an active call).

More information

  • During a conversation the volume can be adjusted for microphone and speaker in the "PhoneDialog".
  • You can accept an incoming call by hotkey "Break Key". To activate the hotkey see [Options > Telephony].