How do prepaid users charge for roaming to Vietnam?

Prepaid users make local calls in Vietnam at 4.36 yuan/minute, answer all incoming calls at 6.86 yuan/minute, call back at 9.86 yuan/minute in China, and call Taiwan Province, Hongkong, Macau and other countries and regions 1 1.86 yuan/minute. Sending domestic SMS is 2.86 yuan/message, sending SMS to Taiwan, Hong Kong, Macao and other countries and regions is 3.76 yuan/message, and receiving SMS is free.