NTT is pretty good for Asian ISP but not Chinese ISP.

China Telecom interconnect with NTT in Tokyo and Singapore. But their Tokyo link is highly congested as the bandwidth is insufficient and QoS. (Heard somewhere that the link is only around 60Gbps).
Even their newly Singapore link (in use from 2020) also highly congested.

As for China Unicom, they interconnect with NTT in Osaka. The link also highly congested but depend on area. Some of the area usable, but mostly area is congested.

China Mobile mostly interconnect with NTT in Hong Kong and Tokyo. Depend on area, but mostly usable.

You are right, CT CN2 route is a lot better than normal CT consumer route as it utilize different link.

This post has been edited by michaelkkl: Oct 30 2021, 05:51 PM