Conversion

Hi, My name is Nicolás and I work in a System Integrators Company in Brazil. I'm trying to find something related with H320,H321 and H323. In fact, I really would like how could be the quality of vídeo when I use applications that running over thisd recommendations. If i have an application running over H.320 and I have a H.321 and H323, which kind of Qos I will have with these convertions ?? Thank you and my best regards Nicolás