Many thanks to fitwxc etc expert for helpful infomration on ip phone.
I read all your articles and setup the following and everything works fine for a couple of weeks until I tried to avoid pin in GV VM. Now I can still call out and receiving calls with no issue, but checking VM in GV from my ip phone doesn't work anymore
1. VoipDiscount for outgoing calls, callid was set to my GV number
2. GV+Sipgate for incoming call, call ID is set to my GV number also
3. In GV, the forward number is sipgate number.
Call IDs of outgoing and incoming calls are correct. I have voice mails in GV mail box.
I use my ip phone to call GV number to check voice mail no problem for a couple of weeks. The otherday when I changed GV setting to avoid pin if called from sipgate number, after a few tones then became silent. So I changed back to still asking pin. Then I always getting "the number is discnected or not in service" or totally silence.
Now I have to use my cell phone to call GV# to check VM. I used Tmobile prepaid plan. This means I have to pay to check GV VM.
Anything could be wrong in my setting? I search this forum but found no similar issues discussed.
Mr. egame replied yesterday as the following, but I am not convinced.
phone -> ATA -> GV -> SG -> ATA -> phone
If the GV voice is not active then you are calling your self - thus it's busy
because
1. The setting worked before for > 2 weeks.
2. According Mr. egame's theory, if I use another cell registered cell phone in GV to check voice mail, it should be always busy also.
cell phone -> GV -> cell phone
If this is true, any phone registered in GV can't check GV voice mail anymore. I might have other settings missing.