I don't know if this is OBITALK or Google voice?
If I try a reverse DNS lookup on the address, I find no hostname, so I have no idea who owns it. I would guess OBITALK though.
Once you have configured your OBi to work with GV, no server or network infrastructure operated by or on behalf of Obihai/Poly is involved in making or receiving GV calls. Call set up data and audio data flow between your OBi device and GV infrastructure.