The CX SFO
flight last night had the following routing.
directly westward until reaching Japan, and then southwest along Japan, Taiwan, and finally to HK
When I flew SFO
on United (similar route), according to Channel 9, we talked to Oakland Center, SF
Radio or Tokyo on HF
probably using datalink because there was nothing on Channel 9 for that part of the flight,Tokyo Control, Fukuoka Control, Naha Control, Taipei Control, Hong Kong radar.