A VoIP trunk refers to a fixed digital connection that transports voice over a data connection (such as an internet connection). With the transition from traditional phone lines to VoIP, the need arose to handle voice traffic over data connections. VoIP trunks are virtual lines exclusively used for telephony.

These trunks connect an organization’s current phone system to a VoIP provider’s system via an IP connection. This allows traditional phone lines to be replaced with more efficient VoIP solutions. Many companies have already made this switch by adding an IP module to their existing phone system. This enables them to use both VoIP and traditional connections.

Capacity and Flexibility

A major advantage of VoIP trunking is scalability. With old ISDN lines, the number of channels was limited, and expansions were expensive and time- consuming. If more people called than the available channels on your ISDN line, they would hear a busy signal: the phone line had reached its maximum capacity.

With VoIP trunks, you determine the number of lines you need. This number can be easily and almost instantly adjusted via your provider, ensuring you always have enough capacity for incoming calls, outgoing calls, and international calls.

For example, each voice channel requires about 100 kB of bandwidth. With a 100 MB internet connection, you can support up to 1,000 voice channels. This flexibility and low subscription costs make VoIP trunks an attractive choice for businesses with large or growing telephony needs.

It’s important to note that with a VoIP trunk, you are responsible for the availability of your own phone system. This is not a fully hosted VoIP solution but a digital phone line specifically for your telephony traffic.

SIP Trunking: A Protocol for Communication

The terms SIP trunk and VoIP trunk are often used interchangeably but are not the same. SIP stands for Session Initiation Protocol and is the protocol used to manage voice traffic. SIP trunks connect and register devices, such as phones and phone systems. Functions like initiating calls (INVITE), ending calls (BYE), and registering devices (REGISTER) are handled via the SIP protocol.

Most modern phone systems support SIP trunking. By connecting a SIP trunk to an existing phone system, you can easily transition to a more efficient VoIP environment without the need for a completely new infrastructure.

Conclusion

VoIP and SIP trunking offer a modern solution for businesses looking to optimize their telephony. Thanks to flexibility, scalability, and low costs, it’s a future-proof choice that’s easy to implement, whether you’re using an existing system or a completely new infrastructure.

Request your own trunk today! Want to first apply for a new business phone number? That’s also possible with us. Have questions? Feel free to contact us—we’re happy to help!