Features * Add support for DTLS Connection ID as defined by RFC 9146, controlled by MBEDTLS_SSL_DTLS_CONNECTION_ID (enabled by default) and configured with mbedtls_ssl_set_cid(). Default behavior changes * Previously the macro MBEDTLS_SSL_DTLS_CONNECTION_ID implemented version 05 of the IETF draft, and was marked experimental and disabled by default. It is now no longer experimental, and implements the final version from RFC 9146, which is not interoperable with the draft-05 version. If you need to communicate with peers that use earlier versions of Mbed TLS, then you need to define MBEDTLS_SSL_DTLS_CONNECTION_ID_COMPAT to 1, but then you won't be able to communicate with peers that use the standard (non-draft) version. If you need to interoperate with both classes of peers with the same build of Mbed TLS, please let us know about your situation on the mailing list or GitHub.