To use the app, you have to login with your DFN VoIP Centrex username and password. These are the same credentials you would use at https://start.voip-centrex.dfn.de.

Upon the first login, the app will guide you through the settings for

• Permissions required for the app to work
• Registration of the mobile number

These settings can be changed later on. Please be aware that without the proper permissions the app might not work as intended.

When you log into the app for the first time, it requires you to select

• A country for emergency calls (the emergency number is selected depending on the country; if you are travelling to another country, change this setting)
• A call-through country (used for initiating GSM calls; please be aware of phone charges and roaming costs)

When you log into the DFN VoIP Centrex iOS app for the first time, the app requires you to give access to

• Microphone

This permission is required for the app to work.

• Local contacts
• Video camera
• Notifications

These permissions are not required for the app to work.

If you would like to receive calls via GSM, you can register your mobile phone number.

After you have entered your phone number and registered it, you will receive an SMS with a verification code which you will have to enter to complete the registration.

Please note that you are not required to register your phone number when logging in for the first time. You can skip it and always do it at a later time.

On subsequent logins, you can log into the app using Touch or Face ID if you have activated it during the first login.

If you are logged into the DFN VoIP Centrex app on any other device, you can choose to continue an active session with its settings, delete that session or create a new session.

The History tab shows a list of recent calls. The call history is updated automatically; however, you can manually update it by swiping from top to bottom.

In this view, you can

1. Switch to Missed calles
2. Switch to Voicemails
3. Edit the calls (delete all or select some calls and then delete them). You can also delete a specific call by swiping across the call entry from right to left. It is also possible to delete a call entry if you click on the info button or the arrow symbol on the right; the Delete entry option is shown then.
4. See incoming calls (no symbol)
5. See missed calls (in red)
6. See outgoing calls (upwards-pointing arrow)
7. See information about the caller and when the call was made
8. See that the call has been transferred. If you click on the arrow, you can see who the call was transferred by.
9. Switch to Favourites, Search, Dial pad or Settings tabs

In the Voicemeils tab, you see the list of the voicemails.

In this view, you can

1. See who left the voicemail and when
2. Forward the voicemail per email (a Forwarding window appears)
3. Delete the voicemail
4. Turn on the loudspeaker
5. Play the voicemail
6. Call the person who left the voicemail
7. Edit the voicemails (delete all or select some voicemails and then delete them)

In the Search tab, you can search for dial targets from the PBX as well as your phones contacts.

In this view, you can

1. Search for contacts, conferences and groups from the PBX. Please note that only the PBX contacts, conferences and groups are searched by default.
2. Search for contacts on the device you are using (only if you have given the DFN VoIP Centrex app the permission to access local contacts)
3. Clear last searches (only the last ten search results are displayed)

You can perform a search in PBX contacts, conferences and groups or on your phone.

In this view, you can

1. Start a search by clicking on the looking glass and entering the name or number
2. Go back to the general search page by clicking on the filter symbol

When you find the conference you have been looking for, you can

1. Subscribe to the conference
2. Join the conference (PIN required)
3. Go back to the general search tab

In order to initiate a call, simply click on any of your favourites, call history or search result. In case you want to dial a specific number, open the dial pad and type the number you want to dial.

When in a call, you can

1. See who you are in a call with and for how long
2. Open the options for the call
3. Mute the call
4. Open the dial pad
5. Select the audio output
6. Add another call
7. End a call
8. Switch to GSM (if you have registered a mobile phone number)

If you tap the options button (2 in the previous image), you can

1. Switch to a video call
2. Hold the call
3. Transfer the call
4. End the call

When you are in a call with someone and want to transfer the call to another person without asking the latter if the transfer is possible:

1. Tap Transfer call to... in the options menu.
2. The Transfer call? window appears.
3. Type in the name or the number of the contact you want to transfer the call to.

Tap OK to transfer the call or Cancel to return to the search for contacts.

The call is being transferred to the selected contact.

When you are in a call with someone and you want to transfer the call to another person and you talk to this person first and he/she decides whether to accept the call or not:

1. Put the first call on hold.
2. Call the second person while the first call is on hold and ask.
3. Transfer the first call to the second call.

Incoming calls via DFN VoIP Centrex are received like regular calls

• While the phone is locked

Incoming calls via DFN VoIP Centrex can be received like regular calls

• While using another app / the app in background

Incoming calls via DFN VoIP Centrex are received like regular calls

• While using the DFN VoIP Centrex app/another app

You can only switch the VoIP call to GSM if you have registered your mobile phone number.

To switch to GSM, tap Switch to GSM, and then OK in the pop-up message.

By switching the VoIP call to GSM, the VoIP call will end and a GSM call will be generated in the background.

The settings tab is devided into the following sections:

• Extension information
• Do not disturb
• Call forwarding profile
• General settings
  • App permissions
  • Language
  • Login with Touch or Face ID
• Call options
  • GSM settings
  • Device to call with
  • Emergency number handling
• Support
• Legal

Furthermore, you can end the current session by tapping Logout in the upper right-hand corner from there.

The extension information shows the internal extenstion number. Inbound number shows the phone number at which your extension can be reached externally.

If you activate DND, the red banner appears at the top of the app interface.

Each user has a default call forwarding profile. It is active per default.

In the DFN VoIP Centrex Web App, you can create your personalised profiles for certain scenarios, for example, Meeting, Home office, Holiday, assign a colour to them and set a target phone number to which the call can be forwarded to. In the mobile app, you can select between the call forwarding profiles.

You can only edit the Default call forwarding profile in the app. Tap on the information button to edit the profile.

In this view, you can enable or desable or set settings for

1. Always. If you enable Always, both Busy and No answer profiles will be overruled.
2. Busy. Here, you can enable/disable it, redirect the calls to voicemail, to a contact or a phone number.
3. No answer. Here, you can enable/disable it, change the timeout between 5 and 60 seconds, redirect the calls to voicemail, busy, to a contact or a phone number.

In General settings, you can

• Change the app permissions. You will be taken to the DFN VoIP Centrex permissions.
• Change the app language. Please note that you can only select between the languages installed on your mobile phone.
• Actuvate/deactivate login with Touch or Face ID

In this view, you can

1. Register your mobile phone number. Please note that it is only possible if your device has a SIM card installed.
2. Change the settings for the call-through options. Please not that it is only possible if you have registered a mobile phone number.
3. Activate/deactivate the GSM only option. Please note that charges can occur, depending on your phone contract.

In Device to call with, you can

1. Add another device
2. Select This device. The calls will be made from the device you are currently using only. This is the default setting.
3. Select All other devices for my extension. All devices will ring apart from this device.
4. Select a customised device to call with. If you add a customised device in the mobile app, it will also be available in the web app.
5. Edit the customised device (change the name of the device, the number or delete the entry).

If an extension number coincides with the emergency number, you have select what you want to call.

In this view, you can set the setting to

1. Call emergency number
2. Call the extension
3. Always ask before you make the call.

In this view you will find all the necessary information, should you need to contact our Support team.

Tapping on Imprint, Data Protection or GTC will take you to the DFN website with the respective documents.