Abstract: It is an important problem for UDP streaming media server to get through the intranet so that the client computers can visit it smoothly. It is necessary for the streaming media server know the address and port where the data will be sent. However, intranet clients by NAT Server can’t tell the streaming media server such information. It proposes a method called ClearNat that provides address mapping related to ClearSerer streaming media server. By providing mapping information between NAT IP & port and Intranet IP& port, ClearNat method makes the ClearServer transmit data to the client smoothly. Results show that the method has the advantages of small computing complexity, supporting large concurrent clients, less modification for main program of ClearServer and little affecting of ClearServer’s effectiveness.

Key words: UDP, NAT, ClearServer streaming media server, address mapping

摘要： UDP流媒体服务器如何穿透内网满足客户端点播是一个重要的问题。UDP流媒体服务器发送数据之前需要知道发送目的地址(包括IP地址和端口号)，而通过代理服务器点播的内网用户无法告知流媒体服务器。该文针对流媒体服务器 ClearServer，提出了一种ClearNat地址映射方法，通过提供NAT地址和端口、内网地址与端口的映射，使ClearServer发送数据到客户端。结果表明，该方法计算复杂度小，支持内网“大并发用户”，对ClearServer主体程序没有影响。

关键词: UDP, NAT, ClearServer流媒体服务器, 地址映射

CLC Number: 

• TP391