Fa Hien or Faxian who was a famous Chinese traveler, visited India during his reign of Chandragupta II. He came through land route and went back through sea route.
Viharas were for the purpose of living, Chaityas were assemblies for the purpose of discussions. Further, Chaityas were with Stupas, Viharas did not have stupas.
According to the Rabatak inscription, Kujula Kadphises was the great grandfather of the great Kushan king Kanishka I. He is considered as the founder of the Kushan Empire. He died in the year 80 A.D.