Considering the political weakness of India in the contemporaries period progress in external trade seemed impossible. But the grow of Islam in the 7th century created a new situation.
With the inspiration of Islam the new adherents spread out in differed directions for trading and other purposes. The Arab merchants use to go up to Canton in China.
In this trade India used to act as an intermediary. The Arab merchants proceeding from their count) first reached Quilon, and from there the Arab merchants proceeds towards Canton.
It is referred to in the writings of the Arab write that Arab merchants from the Persian Gulf regularly visited Go Sopara, Choul, etc.
Not only that, under the Pallavas and Cholas of South India as also the Palas of Bengal regular maritime contact was revived with China.