I just learned from Bitsyncom that tracking numbers aren't generated until they leave mainland China [i.e. Customs]. Then it is handed off to DHL which then generates the tracking number.
I experienced this several times before with packages (fpga's) from NGZ.
Package untraceable until arrival at DHL office in Europe.
My FPGA were shipped to local forwarder first and after a couple of days i got the DHL tracking number