There are a variety of telephone systems on the market for different requirements. You should consider in advance which functions you need. A FRITZ!Box, which can also operate a SIP trunk with up to 20 extensions, is often sufficient.

To ensure full functionality, we recommend that you use one of our certified telephone systems. We have carried out extensive tests in cooperation with the telephone system manufacturer to ensure full compatibility with our SIP trunks. Our Clou PBX, which you can also test free of charge for 30 days in combination with a SIP trunk, is also an inexpensive and advanced alternative.

If you are still using an old telephone system, it may be sufficient to connect a so-called media gateway, which translates between the IP standard and older standards such as ISDN. This is inexpensive, but you will miss out on some of the new functions offered by a SIP trunk.

Read instructions for certified telephone systems.

Back

Created on: 09. July 2025