摘要
伴随着Internet技术获得的巨大成功,IP技术成为未来信息网络的支柱技术之一,以IP为核心的分组化和以移动通信为核心的无线化已成为电信网络演进的主流方向。而软交换技术的出现标志着以多媒体通信为主体的新一代语音电话通信方式的到来。随之,安全和地址缺乏问题也被提到了议事日程表上。网络地址翻译技术一方面起到了安全作用,另一方面也缓解了IP地址缺乏的压力,然而它也并非全无缺点,相反它也带来了一些负面的问题。这主要表现在某些必须将地址信息嵌入到IP数据包负载中的应用层应用如FTP、SMTP等不再有效。其结果,对NAT的穿越成为VoIP技术必须开展解决的一个重大问题。
本文通过分析和比较常用NAT穿越技术中的STUN与TURN穿越技术,并在此基础上提出了综合两者优点,而尽量减小两者缺点的一种将两者相结合的动态转换穿越方案。对于这一穿越方案的实现,本文先是从STUNserver和TURNserver进行设计,然后通过分析该穿越方案下系统的工作流程,提出了算法实现。最后,通过具体实验给予验证。
With the great success of Internet technology, IP technology has become one of the key technologies in the future information network. Packet switch based on IP and wireless communication based on mobilization have become the mainstream of the communication network. And the new-generation VoIP communication appeared with the birth of the softswitch technology based on multimedia communication. Subsequently, the problem of safety and lack of network address is also be made into an argument matter agenda. On one hand, NAT technology makes performance on safety problem; on the other hand, it also alleviates the pressure of lack of IP address. However, it also has defects and brings out some negative influence. This mainly finds expression in some application layer use which must embed address information into IP data packet, such as FTP, SMTP and so on. As a result, NAT traversal technology becomes an important problem for VoIP technology.
Through analyzing and comparing STUN with TURN traversal technology, this paper puts forward a traversal plan that comprehends advantages of STUN and TURN and decreases their disadvanges to the best of their ablities which is named dynamic translation traversal plan . To realize this traversal plan, this paper firstly designs STUN server and TURN server, thus puts forward algorithm realization through analyzing work flow of this system based on this traversal plan. Finally, this paper tests and verifies it through concrete experiment.
引文
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