Zoiper5 supports two types of auto-answering :
Manual Activation via Zoiper Settings
Users can enable auto-answering for all incoming calls through the Zoiper interface.
Navigate to: Settings → Calls → Enable the "Enable incoming call handling" option → Auto-answer → choose either "Instant auto-answer" or "Answer after(1-600sec.)"
Server-Initiated Auto-Answering via SIP Header or Notify Message
The PBX/server can instruct Zoiper to auto-answer using a special SIP header or a SIP Notify message.
Requires proper server configuration and Zoiper settings adjustment.
To accept auto-answering commands from the server, you must enable a specific setting in Zoiper:
Go to: Settings → Automation → Accept server-side auto answer
Make sure this is turned on for either method below to work.
1. Auto-answer through SIP header.
What SIP header format should my server use?
On the PBX (e.g. Asterisk), configure your dialplan with the following syntax:
exten => 100,1,SIPAddHeader(Call-Info:<sip:>\;answer-after=5) exten => 100,n,Dial(Sip/mynumber)
The answer-after=x parameter specifies the number of seconds before Zoiper auto-answers.
Adjust the value x to your desired delay time.
2. Auto-answer through NOTIFY packet.
In addition to SIP headers, Zoiper also supports auto-answering via a SIP Notify message using the "Event: talk" header.
Your PBX must send a SIP Notify message containing: Event: talk
On Zoiper, ensure the following is enabled: Settings → Automation → Accept server-side auto answer