Available "Special Devices"

Standard Phone

For most phone models no direct control is supported. These must be configured as [Secial Device] = "Standard". The call setup is made via "Originate" command of the Asterisk Manager Interface.

Free hand mode via Call-Info : Answer-After=0

Some SIP-phones supports auto-answer via INVITE SIP-Header.


  • Call-Info: Answer-After=0
  • Alert-Info: ;info=alert-autoanswer
  • Alert-Info: <sip:>;info=alert-autoanswer
  • Alert-Info: <sip:domain>;info=alert-autoanswer
    domain = Asterisk IP-Address

See also:

  • www.voip-info.org/wiki/view/Asterisk+Paging+and+Intercom
  • snom phones: In Snom-Web configuration, set the "Intercom Policy" option to "always" or "only in idle" under [Advanced > Behavior]. See also:answer_after_policy
  • Yealink: In the Yealink web configuration, you have to activate "Enable Intercom" under [Features > Intercom].
  • Grandstream:
    • Grandstream 2135: In the Grandstream web configuration, the option "Allow Auto Answer by Call-Info/Alert Info" should be set to "Yes" under [Account X > Call Settings].
    • Grandstream 3240: In the Grandstream web configuration, set the option "AutoAnswer" to "Enable Intercom/Paging" in [Account X > Call Settings].


  • This option requires special adjustments in the telephone system that the manufacturer of the system would have to make.
  • The SIP-SoftPhone or the SIP-telephone responds to special NOTIFY events with parameter "Event: CtiAnswer".

Functionality: When the TAPI driver receives a lineAnswer command via TAPI, it sends a special Action "Redirect". The system would then have to generate a special NOTIFY event with the parameter "Event CtiAnswer". The SIP-SoftPhone or the SIP-telephone then answers the incoming call.

Especially supported IP phones

  • snom
  • Aastra
  • Yealink
  • Tiptel
  • DECT phones are not supported

The actions Dial, Answer and Drop are sent directly via HTTP to the IP phone (the same way like via web browser).

X-Lite, X-Pro, eyeBeam, other SoftPhones

The dialed numbers are sent via the command line directly to the softphone.
The softphone must support "Dial" via command line.

In the configuration dialog you have to enter the path to the application.