To connect network instances in different regions, you must purchase a bandwidth plan and set cross-region bandwidth resources.
Background information
For example, a CEN instance is associated with a 20 Mbit/s bandwidth plan that connects the mainland China area to the North America area. You can set cross-region bandwidth resources that connects the US (Silicon Valley) region to the China (Shanghai), China (Hangzhou), or China (Heyuan) region. The sum of the bandwidth values in different regions cannot exceed 20 Mbit/s.