Forward Calls
With a single tap, transfer an ongoing call to a contact or another number—either directly (blind transfer) or with confirmation: You first briefly announce the call and then transfer it.
VoIP softphone for iOS and Android
DUSphone
Make encrypted HD phone calls—via your dus.net connection
DUSphone is the VoIP softphone for your dus.net account. Make encrypted calls in HD quality directly from your smartphone—incoming calls ring natively in the iOS and Android call UI, even when your device is locked.
- Encrypted (TLS/SRTP)
- HD Voice
- Reliably rings in the background
- Set up in seconds using a QR code
- Made in Germany
- Encrypted
- No Tracking
What's New in DUSphone 7.1
Transferring Calls – Just Like on a PBX System
With version 7.1, DUSphone becomes a full-featured telephony solution for your dus.net connection: Transfer calls and manage multiple calls at the same time—directly from your iPhone or Android smartphone, with encryption and in HD quality.
Call Waiting & Second Call
If the phone rings during a call, simply answer the second call. The first call will be placed on hold, and you can easily switch between the two lines at any time.
Improved in Every Way
A clearer brand presentation, more reliable notifications during calls, and numerous minor improvements for even more stable calls.
Everything You Need for Making Calls on Your Smartphone
Encrypted, private calls in HD—with native call integration and setup in seconds.
Dialing & Making Calls
Standard keypad with dial tones; pressing and holding the 0 key enters the "+" symbol for international phone numbers in E.164 format.
Native Call Integration
Incoming and outgoing calls appear just like regular calls—on the lock screen and in the call log.
Forward Calls
Transfer ongoing calls with a tap—either directly (blind) or with confirmation (attended transfer).
Call Waiting & Second Call
Answer a second call, put the first call on hold, and easily switch between the two lines.
Always Reachable (VoIP Push)
Calls ring reliably, even when the smartphone is locked or the app is closed.
Encrypted HD Voice Calls
TLS/SRTP encryption and HD voice quality directly from your smartphone.
Setup via QR Code
Log in using a QR code or configuration code from the Customer Center—no need to fill in server or SIP fields, and no need to type in a password.
Contacts & Caller ID
Company phone book and device contacts; incoming calls display the name instead of just the number.
Multiple connections
Set up and switch between multiple dus.net connections; the status is visible at a glance.
Keep Track of Your Balance
Prepaid balance in euros—viewed in real time from the Customer Center on the account dashboard.
Control the calling number (CLIP/CLIR)
Show or hide your number (make an anonymous call); if you have multiple numbers, select the one to display.
DUSphone in Detail
Making calls, answering calls, setting things up—that's what DUSphone is like on a smartphone.
Select
Vote as usual
The familiar keypad with dial tones makes making a call a breeze—no training required.
Press and hold the 0 key to enter the "+" symbol, allowing you to dial international numbers directly in E.164 format.
Calls
Rings natively in the iOS and Android call UI
Incoming calls appear just like regular phone calls—on the lock screen and in the call log.
With VoIP Push, DUSphone rings reliably, even if the smartphone is locked or the app is closed.
Facility
Set up in seconds
Login is done using a QR/config code from the Customer Center—no need to fill in server or SIP fields, and no need to type in a password.
Thanks to the company phone book and device contacts, incoming calls display the name instead of just the number.
Security & Privacy
Private conversations stay private: DUSphone encrypts calls and deliberately avoids tracking.
Encrypted HD Voice Calls
Signaling via TLS, calls via SRTP—in HD quality.
Open-source foundation
DUSphone is based on open-source software (baresip/libre); the licenses can be viewed within the app.
No Tracking
No tracking, no ads, no analytics. Device contacts remain stored locally on the device.
Login credentials stored securely
Your password is stored only locally on HA1; the login credentials are stored in the device's secure key store.
Frequently Asked Questions About DUSphone
The app is free. Calls are made using prepaid credit; the starting balance is €0.45.
Yes. DUSphone is the softphone for your dus.net account.
Yes. Calls are encrypted using TLS and SRTP; signaling is encrypted via TLS, and the call itself is encrypted via SRTP.
Available on iPhone and Android. The iOS app is available in the App Store, and the Android app is available on Google Play.
Scan the QR code from the Customer Center—that's it. You don't need to fill in the server and SIP fields.
Get DUSphone on Your Smartphone
Download DUSphone, sign in using the QR code from the Customer Center, and make encrypted HD calls.
Open the QR code in the Customer Center