Hello @palany I have a suggestion you can consider You can ensure that the SIP and RTP ports are properly mapped and that no additional firewall rules are blocking the rtp stream. You can Verify the SIP and RTP configurations in both Kamailio and FreePBX. You can Review your kamailio.cfg for any settings that might be affecting the SIP signaling or media handling. Analyze the PCAP files you have attached for any anomalies in the SIP signaling or RTP stream. You can ensure that the integration with Microsoft Teams is correctly configure.