I've heard of several ISP "available" in Mainland China and offering IP
transit services, but I when contacted they never confirmed they're
providing the access to Mainland China Netizens, as, as far as I know,
the only historical backbone in Mainland China is ChinaNet (owned by
China Telecom), later split into ChinaNet in North China and CNC (now
merged with China Unicom) in South China, for economical reason and
competition purpose. For this reason, I don't believe private and
foreign companies could have deploy their own and provide an alternative.
Smaller ISP often cover the last miles, adding more risks of service
disruption, latency, etc.
Anyway, my point was: don't think that because you're "in" China,
everyone can reach you. Don't go CDN either thinking it's a good
solution*. China is complex, you may lose a lot of time and/or money
deciding for a final solution at first sight. Define your current needs
and plan out futures', and get good contacts there. Take your time and
try out different providers.
*I've heard about an interesting solution of testing and weighting
(price, best time of efficiency, etc.) different CDN providers, you can
contact me to know more about it
