SIP trunk phone connections
Up to 200 parallel calls
Phone number without monthly costs
Up to 1 year free test period*
Hosted PBX with numerous features
Easy and intuitive handling
Extensions from 60 cent/month*
Internet & phone for businesses
VDSL connections with up to 100 Mbps
SIP trunk telephone connections
Integrated Cloud PBX on demand
- SIP trunks
- Cloud Telefonanlage (Cloud PBX)
- Business DSL solutions
Outgoing calls do not work. Why can't I call?
There can be many reasons for faults during outgoing telephone calls.
- First of all, please test whether the incoming calling is working.
- If not, please follow the steps described in this manual.
- If the malfunction occurs when dialing special or service numbers, please click here.
- Test whether an alternative VoIP-enabled device, e.g. a softphone or a VoIP app, is working.
If the problem persists afterwards, please send us a current call example with the key data from this help article to firstname.lastname@example.org