hello, I have just started to evaluate 3cx phone system. i can not get my one linksys spa942 to register. i have another spa942 that registers fine and work but i can not for the life of me figure out what is different.. i am behind a nat phones are on firmware version: 6.1.5(a) the phone im having issues with is saying Failed(No Response) but yet my other one is working fine???? i have tried to set both phone w/ the same information one works one don't. as far as i can tell they have the exact same settings. the one phone dose not even show up in the log saying that its trying to register. any help would be appreciated.