I ran a packet sniffer on my computer and tried to use my soft phone on my own computer. Saw registration attempt. I'll attach it as an image here I guess.
The 192. address is the computer with softphone.
Now, please note this is not using DNS SRV. But, on my neighbors' ISP connections it DOES register and work normally. My ATAs are set for DNS SRV and they only are working when I bring them to my neighbors' ISP connections.