Hope ou're all good. I am new to VOIP and am having issues with cisco voip 7970 phone which is giving me a crackling noise. Now I have tested the phone on another port and it works OK, clearly there is something wrong with the specific port. Can some one please give a gist of steps that I can do in the voip switch/router to find out if there is an issue with the specific ports. Show commands and debugs will be highly appreciated.