Hello I have installed cisco SPA502G. I have used the manual configuration and the documentation available on the 3cx website. I have too thomson ST2030 phone on the same site. The quality of the sound is bad with the SPA502G and i have verified the configuration.... What is the recommended configuration and settings for the SPA502G for codecs and RTP packets to have a good quality of sound ? Perhaps are-they other settings on the 3cx ? are they someone that use the SPA502G for a long time and could help me to verify my configuration... thank's for your help.