Hey benny, thanks for your answer, actually I wanted apply an encryption algorithm on the voice before sending it to the other peer. I found the following char rtp_pkt[RTP_LEN];/**< Incoming RTP packet buffer */ would the voice be encrypted if I encrypt rtp_pkt or I would still need to implement pjmedia_port to do that? -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/attachments/20070921/41f53acb/attachment.html