这段源码是关于目前比较流行的sip面向电信领域的present方面的源码-on this source is currently more popular sip-oriented areas of telecommunications the present source

sip优秀开源代码之一，用来假设sip服务器

SIP协议规范中文版本，目前还没有发现SIP协议的中文版本，故上传后，供需要者共享。-Chinese version of SIP protocol specification, is still not found the Chinese version of SIP protocol, so once it has been uploaded for those who need to share.