The deflation algorithm used by gzip (also zip and zlib) is a variation of LZ77 (Lempel-Ziv 1977, see reference below). It finds duplicated strings in the input data. The second occurrence of a string is replaced by a pointer to the previous

详细描述了基于SIP的VoIP复杂的安全问题，并且阐述了身份认证、加载MIME消息体 来扩展SIP消息和加密包等解决方法。提出一套新的安全框架，在链路层和网络层(交换机)、传输和会话层(防火墙)及应用层(基f-jl~．务器的软件等)多个层实施安全措施来根本解决诸多安全隐患。-A detailed descr iption of SIP-based VoIP complex security issues and expounded on authentication, loading MIM

I P N C 相关的O n v i f部分-The Part of ONVIF communication about the IP camera