If your business traffic may spike, we recommend that you enable the burstable clean bandwidth feature for your Anti-DDoS Pro or Anti-DDoS Premium instance. This avoids packet loss when the peak service traffic exceeds the clean bandwidth of your instance.
Prerequisites
An Anti-DDoS Pro instance is purchased.
For more information, see Purchase an Anti-DDoS Pro or Anti-DDoS Premium instance.
Background information

- If the clean bandwidth of your instance cannot meet your business requirements, you must upgrade your instance to increase the clean bandwidth. For more information, see Upgrade an instance.
- If the clean bandwidth of your instance can meet your daily business requirements
but cannot meet the requirements to handle traffic spikes, we recommend that you enable
the burstable clean bandwidth feature.
After you enable the burstable clean bandwidth feature, you can specify a burstable clean bandwidth to increase the upper limit of the total bandwidth that is supported by the instance. You are charged for the burstable clean bandwidth based on the pay-as-you-go billing method. For more information about the billing for the burstable clean bandwidth, see Billing of the burstable clean bandwidth feature.
Scenarios
We recommend that you enable the burstable clean bandwidth feature for your instance in the following scenarios:
- Holiday promotions, such as Black Friday
- Release of services, such as launch of a new gaming server or new product
- Sharp increase in the number of access requests to websites, such as access requests to online course selection systems and government lottery systems within a specific period of time
Limits
After you enable the burstable clean bandwidth feature, the total bandwidth of the Anti-DDoS Pro instance can be up to 5 Gbit/s. The total bandwidth is equal to the clean bandwidth plus the burstable clean bandwidth that you specify. The burstable clean bandwidth cannot exceed nine times the clean bandwidth.
- If the clean bandwidth is 100 Mbit/s, the maximum burstable clean bandwidth that you can specify is 900 Mbit/s. If you specify a burstable clean bandwidth of 900 Mbit/s, the Anti-DDoS Pro instance supports the maximum service traffic of 1 Gbit/s.
- If the clean bandwidth is 1 Gbit/s, the maximum burstable clean bandwidth that you can specify is 4 Gbit/s. If you specify a burstable clean bandwidth of 4 Gbit/s, the Anti-DDoS Pro instance supports the maximum service traffic of 5 Gbit/s.
- If the clean bandwidth is 5 Gbit/s, you cannot enable the burstable clean bandwidth feature. In this case, if you need a higher bandwidth, submit a ticket or contact customer service.
Enable the burstable clean bandwidth feature
- You can disable the burstable clean bandwidth feature for each instance only once within one calendar month. If you disable the burstable clean bandwidth feature in a month, you are charged for the burstable clean bandwidth that you use when the feature is enabled in this month.
- The burstable clean bandwidth feature is automatically disabled in the following scenarios:
- Your instance expires. Expired instances do not provide services.
- Your Alibaba Cloud account has an overdue payment. In this case, all services that are charged based on the pay-as-you-go billing method are unavailable.
To continue using the burstable clean bandwidth feature, you must renew your instance or settle the overdue payment and enable the feature.
To view the operation logs of the burstable clean bandwidth, navigate to the View operations logs.
page. You can view the logs that are generated when you enable and disable the burstable clean bandwidth feature and modify the burstable clean bandwidth. For more information, seeQuery bills for the burstable clean bandwidth
After you enable the burstable clean bandwidth feature, you can query the bill for the burstable clean bandwidth for each calendar month. To query the bills, log on to the Anti-DDoS Pro console and navigate to the page.

- At 10:00 on the first day of each calendar month, the bill for the burstable clean
bandwidth of the previous month is displayed on the System logs page, and Alibaba Cloud sends notifications to the contacts of your Alibaba Cloud
account by email.
The bill is in the To be billed state. The bill covers only the burstable clean bandwidth that you used within the previous month. You can view the bill details to check the usage of the burstable clean bandwidth within the previous month. For more information, see Query system logs.
If you have any concerns about the usage of the burstable clean bandwidth, submit a ticket. If the amount of the burstable clean bandwidth in the bill is different from your actual usage, the bill is terminated, and you are not required to make a payment.
- If you do not have concerns about the bill, the bill of the previous month is displayed
on the System logs page at 10:00 on the tenth day of the current month.
The bill is in the Already billed state, and the fees are automatically deducted from the balance of your Alibaba Cloud account. Make sure that the balance of your Alibaba Cloud account is sufficient. If your account has an overdue payment, all services that are charged based on the pay-as-you-go billing method become unavailable. The burstable clean bandwidth feature also becomes unavailable.