RFC 文档RFC 5764 - Datagram Transport Layer Security (DTLS) Extension to Establish Keys for the Secure Real-time Transport Protocol (SRTP)2. 约定本页总览2. 本文档使用的约定2. 本文档使用的约定 本文档中的关键词 "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", 和 "OPTIONAL" 应按 [RFC2119] 中的说明解释.