Some VoIP platforms support Intercom/Broadcast groups, the platform can send an INVITE with a special header that enables the phone to answer the call automatically.

Maxwell support the following headers for auto-answer:

  • Call-Info: <sip:ip.addr-pbx>;answer-after=0
  • Call-Info: <sip:>;answer-after=0
  • Call-Info: <sip:>;info=alert-autoanswer;delay=0
  • Call-Info: <sip:ip.addr-pbx>;info=alert-autoanswer;delay=0
  • Call-Info: <uri>;answer-after=0
  • Alert-Info: Ring Answer + Call-Info: answer-after=0
  • Alert-Info: <[some.address]>; info=alert-autoanswer

Please Note

Values, which are different to 0, are not supported.

Phone settings

In the Maxwell you can define what should happen if the call is ringing and this header is available.

Calls via Call Manager, accept call directly:

  • Via headset
  • Via handsfree
  • No (Device will ring and you need to answer manually)

Auto provisioning
Parameter nameDescription

0 = No
1 = Headset
2 = Handsfree

Telephony.Speechpath.IncCallsWithoutCallManager0 = No
1 = Headset
2 = Handsfree
Telephony.Speechpath.OutCallsViaFunctionKey0 = No
1 = Headset
2 = Handsfree


<param name="Telephony.Speechpath.CallsViaCallManager" value="0"/>
<param name="Telephony.Speechpath.IncCallsWithoutCallManager" value="0"/>
<param name="Telephony.Speechpath.OutCallsViaFunctionKey" value="2"/>

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