As of mid-September, says GSMA, Viettel customers in the nine markets of Laos, Cambodia, East Timor, Cameroon, Haiti, Mozambique, Burundi, Peru and Tanzania topped 26 million, bringing the company’s total customer base to 90 million.GMSA said in its report that Viettel now ranks as one of the 30 largest telecom operators in terms of customer base, with 64 million local and 26 million foreign customers.