What is a VoIP connection?

It is now possible to save costs in the business sector by switching to internet telephony (IP telephony). To use them, you need a VoIP connection and a SIP provider.

VoIP and SIP - how it works

In order to use the internet for calls at home and abroad instead of the conventional fixed network telephone connection at a provider such as Telekom, a VoIP connection is indispensable. It is requested from the SIP provider, whereby SIP and VoIP are not synonyms, but rather two protocols that are used for IP telephony. Devices and components or prerequisites and protocols include:

  • IP telephony system or VoIP telephone
  • Broadband internet connection from an internet provider of choice
  • SIP trunk for connection setup and accessibility for internet telephony
  • IP providers with servers for the data transmission network
  • VoIP for the transmission of voice data over the internet

Depending on which components you choose and use, you can look forward to enjoying free or cheaper phone calls.

The VoIP connection

Various providers lure with offers where you buy the DSL connection and the VoIP connection together as a package. Anyone who prefers to look at special offers and e.g. focuses on call rates and services can rely on a provider for broadband connections - preferably VDSL - and on another provider for Voice over IP. It is beneficial if the provider uses SIP trunking. SIP has become the standard protocol for internet telephony in Germany and enables compatibility with other services. This distinguishes SIP from video telephony over the internet, such as Skype, where you depend on the provider’s software and service.

When deciding on a VoIP connection, it is also beneficial if the provider supports the ENUM look-up procedure. This is understood to mean an automatic check whether a SIP address is set up for the respective dialed telephone number. If this is not the case, you make the call (toll call) via the fixed network instead of the broadband line. The number(s) are connected by selecting the connection package and tariff services. Some SIP providers even allow the complete transfer of the existing fixed network number to the VoIP connection. However, in the case of analog telephone connections, this means that the telephone connection and the DSL connection must be terminated. Sometimes you have the possibility to use the fixed network number for VoIP at the same time. Customers keep their fixed network phone number and can be reached by other VoIP users on their IP phone, while all other callers reach them as usual on their conventional phone. Other providers also offer phonebook entries for the number of the VoIP connection. Other services that can be combined with the connection are theoretically telephone number forwarding, conferences, parallel call, brokering, call waiting and message delivery by e-mail.

Consulting & implementation

Your IP phone connection

Unified Communication and Collaboration (UCC)


Service & maintenance

Would you like to contact toplink directly?

You can reach us personally at:
+49 6151 6275 0

We will be happy to answer your e-mail inquiry under:

Number of PC workstations*
0 of 500
WordPress Cookie Plugin by Real Cookie Banner