陈上伟博士:

Firstly, I thank you very much for your time and your serious reply!

According to your opinion, if always working, the person who has Niederlassungsbewilligung (Schluesselkraft, Unselbstaendige Erwerbstaetigkeit Bei eine Firma) can apply for the permenant residence 18 months later starting from issuing of the permenant residence.

Then, when it is the time for the person to apply for the nationality, 6 years later because of the Schluesselkraft?

Further, does the 6-year period start from issuing the Niederlassungsbewilligung or the permenant residence? From the Niederlassungsbewilligung?

Thanks again!