I think you have misunderstood what I would like to do. I don't need hairpin mode, the 2 IPM devices are not connected together.
The first IPM device (on the first host interface) send its data over IP to an external router, which routes back the IP traffic to the second IPM device (on the second host interface).
What I'm trying to do:
1. Connect a voice device to an IPM device 1 to be able to play voice, RTP is sent out to the external network over host interface 1 (this is working)
2. Connect a voice device to an IPM device 2 to be able to record voice, RTP is received from the external network over host interface 2
The second part doesn't work. Please have a look at my small code I have attached in my previous post (ipm_record.zip).
Thank you.