在开发sip通话或者h323的时候，都想需要作认证，所以这里给出本人开发的一个很小的digest认证流程的小例子。-call in the development or sip h323 time, and they all want to require certification So I developed here is a very small digest authentication process small examples.

sip服务器原代码,要求在linux或者unix下安装,可以用于建立自己的voip系统,基于sip协议-OpenSIPS brings: robust and performant SIP (RFC3261) Registrar server, Location server, Proxy server and Redirect server small footprint- the binary file is small size, functionality can be stri