Re: Can anybody help me ?
that's a lot of subjects, i can reply you concerning VoIP:
VoIP is to carry out normal voice signal over a data network working with TCP/IP protocol, the idea is to use DSP to convert analog voice into digital signal , then use protocols like RTP to encapsulate digital signal into packets , then use protocols like H.323 to establish session to transfer the call , and use many queuing , routing , policies and many other techniques to deliver the voice with the same quality as telephony that is Quality of Service QoS
if you need any resources about this subject don't hesitate to ask , i have tons of document and tutorials