Worked on the livekit/sip repository to deliver symmetric RTP support within the SIP package, focusing on enhancing media reliability and interoperability for both inbound and outbound calls. Leveraged Go for backend development and network programming, introducing a dedicated configuration option that allows operators to control symmetric RTP behavior. Updated media connection handling to improve NAT traversal and reduce call failures caused by RTP asymmetry, resulting in more robust call quality across diverse network environments. Developed comprehensive tests to validate symmetric RTP functionality across typical call scenarios, ensuring better test coverage and maintainability for future changes to the SIP protocol implementation.