Vietnam Voice Features and Restrictions

CLI

Voice traffic sent to Vietnam with a local CLI/Caller ID will be filtered or blocked by local operators and carriers unless customer subscribe Vonage Vietnam number. International CLI works as expected and will be delivered to the recipient handset without being filtered. This is in agreement with local operators and suppliers requirements. All other features of Voice calls should be successful.

Advertising calls

• Advertising calls must be immediately terminated after the user sends an opt-out request
• Every advertiser shall not be allowed to make more than 1 advertising call to a single phone number within 24-hours period, unless the user agrees otherwise
• Advertising calls can only be made between 08:00 to 17:00 every day.

Spam Control

Operator is going to block a caller number if

• Making calls to many subs over 30 calls/hr 
• Time between calls is always below 30 seconds.
• Over 90% callee is not related with caller 
• Average Call duration is short. (eg, most of the calls is shorter than 30 seconds)
• The number could not be called back.
• The number have been reported as spam source from many end users.

Other Features or Restrictions

No limitations beyond those in our Acceptable Use Policy.

Additional Information

For more information, see the Voice Numbers Features Overview.