My 10 month old baby does not recognize familiar faces,please help?

My 10 month old baby boy does not recognize familiar faces.Everytime when a stranger whats to hold him he have no problem and he behaves like he does with us.I'm really worried that something is wrong with his development. He does not crawl yet,but he rolls over and he stands and likes to take few steps to walk,he is smilling,talking bababa,dada etc but him not being able to recognize familiar faces worries me lot. Any answer will be very helpfull....thanks!