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Anti-DDoS:Billing of burstable clean bandwidth

Last Updated:Dec 05, 2025

This topic describes the billing methods for the burstable clean bandwidth of Anti-DDoS Pro and Anti-DDoS Premium instances.

Overview

After you add services to an Anti-DDoS Pro or Anti-DDoS Premium instance, random packet loss occurs if the peak service traffic exceeds the Clean Bandwidth limit. If the clean bandwidth is exceeded for a sustained period, rate limiting is triggered, which disrupts normal access to your services. To resolve issues caused by exceeding the clean bandwidth:

  • If the Clean Bandwidth of your instance is insufficient for your daily business requirements, you can upgrade the instance to increase the clean bandwidth. For more information, see Upgrade an instance.

  • If your Clean Bandwidth specification is sufficient for your daily business requirements but not for traffic fluctuations or sudden increases in normal access traffic, you can enable burstable clean bandwidth for your Anti-DDoS Pro or Anti-DDoS Premium instance.

Burstable clean bandwidth provides additional clean bandwidth for your instance on top of its base clean bandwidth. This helps prevent rate limiting caused by normal service traffic fluctuations that exceed the clean bandwidth specification during peak hours. After you enable burstable clean bandwidth, you are charged on a pay-as-you-go basis only for the extra bandwidth used when your peak traffic exceeds the clean bandwidth specification.

Important

If you are a proof of concept (POC) user, do not enable burstable clean bandwidth to avoid incurring pay-as-you-go bills.

Scenarios

You can enable burstable clean bandwidth for your Anti-DDoS Pro or Anti-DDoS Premium instance if the protected services involve the following scenarios:

  • Large-scale sales promotions during holidays, such as Black Friday.

  • New service launches, such as opening a new game server or releasing a new product.

  • Sudden increases in website traffic during specific periods, such as for university course selection systems or government lottery systems.

Supported instance types

  • Anti-DDoS Proxy (Chinese Mainland): Profession, Advanced

  • Anti-DDoS Proxy (Outside Chinese Mainland): Insurance, Unlimited, Sec-CMA 2.0, Sec-CMA 2.0 (Insurance), Sec-CMA 2.0 (Unlimited), Chinese Mainland Acceleration, Sec-CMA 1.0

Burstable bandwidth and total clean bandwidth

Instance service bandwidth limit

  • Anti-DDoS Proxy (Chinese Mainland): Profession (20,000 Mbps), Advanced (20,000 Mbps)保险防护

  • Anti-DDoS Proxy (Outside Chinese Mainland): Insurance(5,000 Mbps), Unlimited(5,000 Mbps), Sec-CMA 2.0 (1,500 Mbps), Chinese Mainland Acceleration (1,000 Mbps), Sec-CMA 1.0 (500 Mbps)

Formulas for burstable bandwidth and total clean bandwidth

  • Formulas

    • Maximum burstable bandwidth increase = min(Base Clean Bandwidth × 9, Instance clean bandwidth limit - Base Clean Bandwidth).

    • Total clean bandwidth (maximum traffic the instance can handle) = Base Clean Bandwidth + Burstable bandwidth increase.

  • Key points

    • Burstable bandwidth is typically nine times the base clean bandwidth.

    • The total clean bandwidth cannot exceed the instance clean bandwidth limit.

    • The potential for a burstable bandwidth increase becomes more limited as the base Clean Bandwidth increases.

  • Example: For an Anti-DDoS Proxy (Chinese Mainland)-Profession instance, the instance clean bandwidth limit is 20,000 Mbps.

    • If the Clean Bandwidth is 100 Mbps

      • Maximum burstable bandwidth increase: 100 × 9 = 900 Mbps

      • Maximum traffic the instance can handle: 100 + 900 = 1,000 Mbps

    • If the Clean Bandwidth is 3,000 Mbps

      • Maximum burstable bandwidth increase: min(3,000 × 9, 20,000 - 3,000) = 17,000 Mbps

      • Maximum traffic the instance can handle: 20,000 Mbps

    • If the Clean Bandwidth is already greater than 20,000 Mbps

      • Maximum burstable bandwidth increase: min(20,000 × 9, 20,000 - 20,000) = 0 Mbps

      • Maximum traffic the instance can handle: 20,000 Mbps

Burstable clean bandwidth pricing

Instance type

Monthly 95th percentile unit price (USD/month/Mbps)

Daily 95th percentile unit price (USD/day/Mbps)

Anti-DDoS Proxy (Chinese Mainland)-Profession, Advanced

15

1

Anti-DDoS Proxy (Outside Chinese Mainland)-Insurance

16

1.05

Anti-DDoS Proxy (Outside Chinese Mainland)-Unlimited

21

1.4

Anti-DDoS Proxy (Outside Chinese Mainland)-Sec-CMA 2.0

155

10

Anti-DDoS Proxy (Outside Chinese Mainland)-Chinese Mainland Acceleration

155

10

Anti-DDoS Proxy (Outside Chinese Mainland)-Sec-CMA1.0

155

10

Billing methods

Important

Burstable clean bandwidth takes effect immediately after you enable it.

Burstable clean bandwidth is a pay-as-you-go feature. It supports two metering methods: daily 95th percentile and monthly 95th percentile.

You can switch between the metering methods. The new metering method takes effect at 00:00 on the first day of the next calendar month. You can change the metering method up to three times per calendar month. The last change made within a calendar month takes effect in the following month.

Item

Daily 95th percentile

Monthly 95th percentile

Fee settlement

Fees are settled on a calendar day basis.

Important

If you enable burstable clean bandwidth for the first time on Day T of a calendar month and select the daily 95th percentile metering method, you are not charged on Day T. Fees are incurred starting from Day T+1, and the bill is generated on Day T+2.

Fees are settled on a calendar month basis.

Billing conditions

Fees are incurred if the 95th percentile bandwidth of a calendar day exceeds the Clean Bandwidth specification.

To calculate the 95th percentile bandwidth of a calendar day, the system collects a bandwidth value from your Anti-DDoS Pro or Anti-DDoS Premium instance every 5 minutes. This results in 288 values per day. The system removes values collected during DDoS attacks and then removes the top five of the remaining values. The highest remaining value is the 95th percentile bandwidth for that day.

Fees are incurred if the 95th percentile bandwidth of a calendar month exceeds the Clean Bandwidth specification.

To calculate the 95th percentile bandwidth of a calendar month:

  1. Obtain the daily peak bandwidth: The system collects a bandwidth value from your Anti-DDoS Pro or Anti-DDoS Premium instance every 5 minutes, resulting in 288 values per day. After the system removes values collected during DDoS attacks, the highest remaining value is the daily peak bandwidth.

  2. Calculate the monthly 95th percentile bandwidth: The system sorts all daily peak bandwidth values for a calendar month in descending order and calculates the average of the top five values. This average is the 95th percentile bandwidth for that month.

Fee calculation formula

Burstable clean bandwidth fee = Billable burstable clean bandwidth (Mbps) × Daily unit price(USD/day/Mbps).

How to calculate the billable burstable clean bandwidth

The billable burstable clean bandwidth is the smaller of the 95th percentile bandwidth of a calendar day and the total clean bandwidth (base clean bandwidth + burstable bandwidth increase), minus the base Clean Bandwidth specification.

Important

If the 95th percentile bandwidth of a calendar day exceeds the total clean bandwidth, rate limiting may be triggered. You must promptly increase the burstable bandwidth or upgrade the instance's clean bandwidth specification. For more information, see Set burstable clean bandwidth and Upgrade an instance.

Burstable clean bandwidth fee = Billable burstable clean bandwidth (Mbps) × Effective factor × Monthly unit price(USD/month/Mbps).

How to calculate the billable burstable clean bandwidth and effective factor

  • Billable burstable clean bandwidth

    The billable burstable clean bandwidth is the smaller of the 95th percentile bandwidth of a calendar month and the total clean bandwidth (base clean bandwidth + burstable bandwidth increase), minus the base Clean Bandwidth specification.

    • Total clean bandwidth: This is the maximum total clean bandwidth that was configured on the five days with the highest daily peak bandwidth values.

    • Base Clean Bandwidth: The Clean Bandwidth specification on the last day of the calendar month on which burstable clean bandwidth was enabled.

      Important
      • If the 95th percentile bandwidth of a calendar month exceeds the total clean bandwidth, rate limiting may be triggered. You must promptly increase the burstable bandwidth or upgrade the instance's clean bandwidth specification. For more information, see Set burstable clean bandwidth and Upgrade an instance.

      • If the service traffic does not exceed the maximum burstable clean bandwidth configured for the month, rate limiting or packet loss does not occur.

  • Effective factor = Number of valid days in the month ÷ Total number of days in the month.

    Important

    If you enable burstable clean bandwidth for the first time on Day T of a calendar month and select the monthly 95th percentile metering method, Day T is not counted as a valid day for that month.

    For example, you enable burstable clean bandwidth on July 15, 2023, and do not disable it in July. The number of valid days is 16, from July 16, 2023 to July 31, 2023. The total number of days in the month is 31. The effective factor is 16 ÷ 31 = 0.51612903.

Conditions

  • You can disable the daily 95th percentile metering method only once per calendar month.

  • You cannot switch the metering method on the last day of a calendar month.

  • You can disable the monthly 95th percentile metering method only once per calendar month.

  • You cannot switch the metering method on the last day of a calendar month.

How to enable burstable clean bandwidth

Bill generation and settlement

The following table describes the billing and settlement times for burstable clean bandwidth.

You can query and confirm billing details for burstable clean bandwidth on the System Logs page. For more information, see System logs.

Metering method

Bill generation time

Settlement time

Daily 95th percentile

The bill for the burstable clean bandwidth that is used in a calendar day is displayed on the System Logs page at 14:00 on the next day, and Alibaba Cloud sends notifications to the contacts of your Alibaba Cloud account by email.

At 17:00 on the next day the burstable clean bandwidth is used, Alibaba Cloud deducts the fee of the burstable clean bandwidth feature from your account balance.

Monthly 95th percentile

The bill for the burstable clean bandwidth that is used in a calendar month is displayed on the System Logs page at 10:00 on the first day of the next month, and Alibaba Cloud sends notifications to the contacts of your Alibaba Cloud account by email.

At 10:00 on the third day of the next month, Alibaba Cloud deducts the fee of the burstable clean bandwidth feature from your account balance.

Billing example

This section provides an example of how to calculate the fees for burstable clean bandwidth using the monthly 95th percentile metering method.

On January 1, 2023, you purchased an Anti-DDoS Pro and Anti-DDoS Premium (Chinese mainland) Professional Edition instance with a base clean bandwidth of 200 Mbps. You enabled burstable clean bandwidth, selected the monthly 95th percentile metering method, and set the burstable bandwidth increase to 300 Mbps. These configurations remained unchanged as of February 1.

From February 3, 2023 to February 6, 2023, you adjusted the base clean bandwidth specification and the burstable bandwidth increase.

On February 8, 2023, you disabled burstable clean bandwidth.

On February 27, 2023, you re-enabled burstable clean bandwidth and set the burstable bandwidth increase to 100 Mbps.

The following figure shows the daily base clean bandwidth, total clean bandwidth, and daily peak traffic. The graph shows data only for the periods during which burstable clean bandwidth was enabled.Burstable service bandwidth_cn

Based on the formula: Burstable clean bandwidth fee = Billable burstable clean bandwidth (Mbps) × Effective factor × Monthly unit price for the instance(USD/month/Mbps), the fee is calculated as follows:

  1. Calculate the billable burstable clean bandwidth

    The billable burstable clean bandwidth is the smaller of the 95th percentile bandwidth of the calendar month and the total clean bandwidth, minus the base Clean Bandwidth specification on the last day that burstable clean bandwidth was enabled. The calculation is as follows:

    1. 95th percentile bandwidth of the calendar month: For this billing cycle, the average of the top five daily peak traffic values is (1,000 Mbps + 500 Mbps + 600 Mbps + 500 Mbps + 400 Mbps) ÷ 5 = 600 Mbps.

    2. Total clean bandwidth: The maximum total clean bandwidth that corresponds to the top five daily peak bandwidth values is 500 Mbps.

    3. Billable burstable clean bandwidth: 500 Mbps - 100 Mbps (base clean bandwidth specification on the last day that burstable clean bandwidth was enabled) = 400 Mbps.

  2. Calculate the effective factor

    The effective factor is 10 (number of days that burstable clean bandwidth was enabled) ÷ 28 (total number of days in the month) = 0.35714285.

  3. Find the monthly unit price for the instance's burstable clean bandwidth

    As specified in Burstable clean bandwidth pricing, the monthly unit price for an Anti-DDoS Pro and Anti-DDoS Premium (Chinese mainland) Professional Edition instance is 15 (USD/month/Mbps).

Based on these results, your burstable clean bandwidth fee is 400 Mbps × 0.35714285 × 15 (USD/month/Mbps) = 2,142.8571 USD.

References