Consult About VoIP

I have a business that uses live voice talent but want to understand more about a vertical market that uses either VoIP or something like it. I don't know for certain that it is VoIP but I am looking for someone who is knowledgeable in this area that can help me understand the technology these sites are using. Respondents will need to either explain *why* they are qualified and tell me they know the answers, or answer one of the three questions to show that they have the knowledge I am looking for. I'm not looking for guesses. 1) I need someone to explain to me how sites like these work from a technical side (or provide link to an article that explains it): [login to view URL] [login to view URL] [login to view URL] You can explain by written word or by making a video of you talking; whichever way serves your time [login to view URL] you do a video, please make it in English. 2) What IT infrastructure is needed to run something on this scale. 3) Most importantly, what software packages are these sites running on and how can I contact the vendor? I am trying to find someone who is very familiar with VoIP technology and would recognize how something like this is accomplished, and ideally, be able to point me to vendors that create this type of software. I do not expect that it would take someone with experience and is familiar with the technology more than one (1) hour to complete all three tasks mentioned above. That is why I set the consultant rate a flat amount. If more time is needed, please justify precisely. I am NOT looking for someone who is not already familiar with this to go research it for me. Feel free to email questions for clarifications if you're not sure about what I need to complete with project. Thank you for reading this all the way through.