老爸北京一签过

I do not know the detail process.
but I just want to point out Dad is so lucky to get visa.

My background is:
I came as F2, then changed to F1, H1,
I have not gone back China for 10 years and this is the first time I invited my Dad to come.
I was so concerned about this before Dad went to visa interview
b/c and I have no official document to show he's my Dad. (for some reasons)

I know my Dad's case is not typical, but just want to say for those who invite parents to come, prepare well, be confident, be honst and good luck.