Worked on improving WebRTC interoperability by addressing a critical DTLS handshake issue in the ossrs/ffmpeg-webrtc repository. Focused on RFC 8827 compliance, the developer enforced the use of the TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 cipher suite and the P-256 elliptic curve during the handshake process. This update reduced publish WHIP handshake failures and improved compatibility across different WebRTC servers. The work demonstrated strong skills in C programming, network programming, and security protocols, with particular attention to integrating GNUTLS within avformat/tls_gnutls. The contribution enhanced cross-vendor reliability for WebRTC peers by resolving edge-case failures in secure media transport scenarios.