Java – Jain-sip automatically sends sip messages

Jain-sip automatically sends sip messages… here is a solution to the problem.

Jain-sip automatically sends sip messages

I wrote a softphone (simulated by SIPp) that could communicate with the PBX. To do this, I use Java’s Jain-SIP framework. My problem is that jain-sip automatically sends sip messages. For example, after receiving a RE-INVITE message, my program sends back an OK message, but jain-sip automatically sends back a TRYING message. Why???

Jain-sip also automatically sends some OK messages. See the call flow below (PBX is sending INVITE messages to my softphone application):

  • Invite –>
  • Confirm –>
  • RTP is sent on port 2000

  • Reinvite –>

  • Confirm –>
  • RTP is sent on port 2002
  • jain-sip automatically sends this message !!!
  • Confirm –>
  • Sending RTP on port 2000 now RTP data goes to the wrong port
  • Jain-SIP then sends an OK message automatically
  • Confirm –>
  • Sending RTP on port 2000 //rtp data go to wrong port
  • Goodbye –>

Why does jain-sip send messages automatically? What am I doing wrong, or is it possible to disable automatic sending of SIP messages?



found that I can stop sending messages automatically by setting the parameter “javax.sip.AUTOMATIC_DIALOG_SUPPORT” to “off”. I also know why jain-sip sometimes sends TRYING messages automatically. This happens when my softphone app takes a long time to send OK messages back to the PBX. What I still don’t understand is the automatic sending of OK messages that I described in the call flow above. Maybe someone knows?

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