g7 series of audio codec code, can help you in the use of voip

osip，exosip，ortp...是在网络电话中使用非常广泛的几个开源库。这里是在VC7环境下已经编译好的lib文件和dll文件，在windows环境下可以直接使用，省却了重新编译的烦恼。-osip, exosip, ortp ... is the phone in the network is widely used in several open source libraries. Here is the VC7 environment has been compiled lib files and dll files in the windows environment, can be used directly without the need to re-compile troubles.

ITU的g729a编码库，可以将pcm转化为g.729格式-ITU G729 annex A lib file ,can transfer PCM file format to G729 format.

客户端使用NetMeeting，服务端使用mfc.exe可以获得比较好的效果-clients use NetMeeting, The server can use mfc.exe fairly good results

rtp协议占源码-rtp agreement for FOSS

a SIP proxy server and service provider

jrtp流媒体传输的code，适合大家参考编程用-jrtp streaming media transmission of code, suitable for everyone with reference programming

一个比较好的基于LINUX平台的网络电话，代码写很有特点，很值得一读-a better platform for Linux-based Internet phones, code written with unique features and is well worth a read

主要通过对SIP协议的研究，根据这个协议的特点，设计出来一个基于SIP电话会议系统。用户可以通过WEB方式登录到预先建立好的会议室，进行电话会议。-primarily through the SIP, according to the characteristics of this agreement, designed a SIP-based telephone conferencing system. Web users can log on to advance ways to establish good meeting rooms, conference calling.

视频会议系统 vc++编程-Video Meeting System Programmed by VC++

Example of the SIP api using peers!