It's a known modification but unfortunately not enough. SIP is really enabled but it is pretty useless due to the annoying voice distortion on the other side of communication. It appears as high-frequency harmonic distortion and disfigures your voice beyond every acceptable level. I've put a lot of effort to resolve the problem but so far without any significant success. The main question is why dedicated sip applications can operate more or less without distortion and native sip can't. The best guess is that native sip (voip) is not managed as telephony function but rather as one of special audio functions. Therefore it lacks acoustic echo cancellation functionality. Or other possibility might be that pretty high latency of native voip is responsible that echo cancellation simply can't "grab". I tried to replace or repair files responsible for voip and general audio, even drivers but without any luck. It must be that the whole problem is somehow connected to radio and baseband management. Hence it would be very interesting to know if voip distortion appears only in MOTOX or in other phones as well. I assume that it is a Google issue but you never totally know before you try it. It may be connected to Motorola baseband configuration solely.



By the way, I was really exited when I read that one of malfunctions supposed to be repaired among hundreds others in Google 4.4.3 release would be internet telephony (voip). Now I'm on stock 4.4.4 and no progress regarding sip was made....