This VoIP-CAPI driver allows ISDN-CAPI applications like the fax server CapiFaxor the answering machine software CapiCallto be operated with VoIP-SIP accounts instead of ISDN connections, for example on an AVM Fritz!Box.

Of course, it can also be used with VoIP-capable routers from Lancom or Bintec and other telephone systems that support VoIP accounts as extensions (Auerswald, Agfeo, 3CX, etc.).

The driver acts on the used server as a replacement for a conventional ISDN card. It can log on directly to your VoIP-enabled PBX, your router, or to a VoIP provider on the Internet. For this purpose, a SIP account is created there, whose access data one enters in the VoIP CAPI.

This way you can easily use programs like CapiFax, CapiCall and other CAPI-based applications on the VoIP connection, be it Telekom’s IP-based connection, DeutschlanLAN IP, Sipgate and many more. Cloud phone systems such as Sipgate Bussiness, NFON and 3CX can also be used.

More Infos: Primux-VoIP-Tipps

Operating system compatibility

Windows: CAPI 2.0 + NDIS for all 32 and 64 bit versions from Windows XP Workstation, Server)

Supported SIP-Codecs

  • ITU G.711 (µ-Law und A-Law)
  • GSM
  • ITU G.723.1
  • ITU G.726
  • G.729


  • SIP2/4-USB: With USB dongle (SIP2-USB for up to two channels, SIP4-USB up to 4 channels), recommended for physical servers, as network card or mainboard replacement is no problem.
  • SIP2/4-MAC: With license file for a MAC address (network adapter serial number), also suitable for virtualized servers: The MAC address is customer-specific and therefore not a standard product; there is therefore no right of return and/or revocation.
  • Versions with 8, 16 and 30 channels are also available on request!

Scope of delivery

  • CD with drivers and documentation
  • USB dongle (-USB) or license file (-MAC)
  • Driver download here, use this latest driver and not the one on the CD!
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