Frequently Asked Questions
Answers to common questions about VoIPSUN PBX.
Is the number of internal lines limited?
No, you can create any number of internal lines. The only limitation is the performance of the hardware used.
What exactly limits the number of concurrent calls?
The limitation applies only to outbound calls from the PBX to the voice service provider (SIP trunk). Incoming and internal calls within the PBX are not limited — their number depends only on hardware performance.
What devices are compatible?
Any phone, converter (analog FXS, ISDN2, ISDN30), GSM gateway, or software client that supports the SIP protocol.
Are custom modifications possible?
Yes. The entire PBX is developed by our in-house team. This allows us to respond flexibly to client needs and implement modifications that standard solutions cannot offer.
What happens during a power outage?
The PBX requires power — we recommend connecting it through a basic UPS. During an outage, backup data connectivity must also be ensured (if telephony depends on internet).
Can I use my existing phones?
Analog phones can be connected via an FXS converter. Proprietary digital phones (Panasonic, Siemens, and similar) use closed protocols and cannot be used with a VoIP PBX.
Can multiple locations share one PBX?
Yes. Remote phones register over the internet to the central PBX. The connection can be secured with encryption (TLS/SRTP) or a VPN tunnel (an OpenVPN client is built into the PBX).