If the public bandwidth configurations of a subscription Elastic Compute Service (ECS)
instance that uses a public IP address are not suitable for your business requirements,
you can modify the public bandwidth configurations.
Prerequisites
Before you can use the downgrade feature to downgrade the fixed bandwidth of an instance
or modify the peak bandwidth of an instance, make sure that your account has been
granted the privilege to perform configuration downgrades. A fixed bandwidth is a
specified amount of public bandwidth allocated to an instance that uses the pay-by-bandwidth
billing method for network usage. A peak bandwidth is the maximum amount of public
bandwidth that an instance can have when it uses the pay-by-traffic billing method
for network usage.
Note You can click Privileges on the Overview page in the ECS console to go to the Privileges and Quotas page and check whether
your account has been granted the privilege to perform configuration downgrades.
Background information
You can modify the fixed or peak bandwidth of an instance based on its billing method
for network usage.
- For instances that use the pay-by-bandwidth billing method for network usage, you
can upgrade or downgrade their fixed bandwidths. For more information, see Upgrade fixed bandwidths or Downgrade fixed bandwidths.
Note A bandwidth downgrade may result in a refund. The following formula is used to calculate
the refund amount: Refund amount = Remaining amount of the price of the original configurations
- Price of the new configurations. Up to three refunds can be made for each subscription
instance. A refund is made if you downgrade the instance type or bandwidth or change
the billing method of a disk from subscription to pay-as-you-go.
- For instances that use the pay-by-traffic billing method for network usage, you can
modify their peak bandwidths. For more information, see Modify peak bandwidths.
When you modify the bandwidth configurations of an ECS instance, take note of the
following limits:
- Your ECS usage determines whether the bandwidths of your instances can be downgraded.
- The bandwidth configurations of an instance can be modified multiple times, but you
must wait at least 5 minutes between two consecutive bandwidth configuration modifications
on the same instance.
This topic describes how to modify the bandwidth configurations of a subscription
instance that uses a public IP address. For more information about how to modify the
bandwidth configurations of a subscription instance that uses an elastic IP address
(EIP), see Modify the bandwidth of an EIP.
Upgrade fixed bandwidths
For instances that use the pay-by-bandwidth billing method for network usage, you
can perform the following operations to upgrade their fixed bandwidths.
Note If you did not assign a public IP address an instance when the instance was created,
the instance has no public bandwidth. You can assign a public IP address to the instance
by upgrading the fixed bandwidth of the instance from 0 Mbit/s to a non-zero value.
- Log on to the ECS console.
- In the left-side navigation pane, choose .
- In the top navigation bar, select a region.
- Use one of the following methods to go to the bandwidth upgrade page based on the
number of instances whose fixed bandwidths you want to upgrade:
- Upgrade the fixed bandwidth of a single instance at a time
- Find the subscription instance whose fixed bandwidth you want to upgrade and click
Upgrade/Downgrade in the Actions column.
- In the Upgrade/Downgrade Wizard dialog box, select Upgrade and click Continue.
- Upgrade the fixed bandwidths of multiple instances at a time
- Select the subscription instances whose fixed bandwidths you want to upgrade. In the
lower part of the Instances page, choose .
- In the dialog box that appears, select Upgrade Bandwidth and click Continue.
- On the page that appears, specify a new bandwidth in the Bandwidth section.
When you upgrade the fixed bandwidths of multiple instances at a time, instances are
filtered out if they are not associated with a public IP address or if they do not
use the pay-by-bandwidth billing method for network usage. You can continue to upgrade
bandwidths only for the eligible instances, as shown in the following figure.

- Read the notes. Read and select ECS Service Terms.
- Check the configuration costs, click Upgrade or Create Order in the lower part of
the page, and perform the subsequent operations as instructed.
Note The first time you upgrade the fixed bandwidth of an instance in the classic network
from 0 Mbit/s to a non-zero value, you must restart the instance by using the ECS
console or by calling the RebootInstance operation for the new bandwidth to take effect.
Downgrade fixed bandwidths
For instances that use the pay-by-bandwidth billing method for network usage, you
can perform the following operations to downgrade their fixed bandwidths.
- Log on to the ECS console.
- In the left-side navigation pane, choose .
- In the top navigation bar, select a region.
- Use one of the following methods to go to the bandwidth downgrade page based on the
number of instances whose fixed bandwidth you want to downgrade:
Notice Bandwidth downgrade operations can downgrade only the baseline bandwidths of instances.
- Downgrade the fixed bandwidth of a single instance at a time
- Find the subscription instance whose fixed bandwidth you want to downgrade and click
Upgrade/Downgrade in the Actions column.
- In the Upgrade/Downgrade Wizard dialog box, choose , and then click Continue.
- Downgrade the fixed bandwidths of multiple instances at a time
- Select the subscription instances whose fixed bandwidths you want to downgrade. In
the lower part of the Instances page, choose .
- In the dialog box that appears, select Downgrade Bandwidth and click Continue.
- On the page that appears, specify a new bandwidth in the Bandwidth section.
When you downgrade the fixed bandwidths of multiple instances at a time, instances
are filtered out if they are not associated with a public IP address or if they do
not use the pay-by-bandwidth billing method for network usage. You can continue to
downgrade bandwidths only for the eligible instances, as shown in the following figure.

Note
- If you downgrade the fixed bandwidth of an instance in the classic network to 0 Mbit/s,
the public IP address of the instance is retained. If you downgrade the fixed bandwidth
of an instance in a virtual private cloud (VPC) to 0 Mbit/s, the public IP address
of the instance is released.
- You can select Pay-By-Traffic to change the billing method for network usage to pay-by-traffic and specify a peak
bandwidth.
- Read the notes. Read and select ECS Service Terms.
- Check the refund amount, click Downgrade Now, and then perform the subsequent operations
as instructed.
Note After you downgrade the fixed bandwidths of instances, you do not need to restart
the instances for the new configurations to take effect.
Modify peak bandwidths
For instances that use the pay-by-traffic billing method for network usage, you can
perform the following operations to modify their peak bandwidths.
Note When pay-by-traffic is used as the billing method for network usage, you are charged
based on the actual volume of traffic. If you modify only peak bandwidths, the configuration
costs remain unchanged. A peak bandwidth is the upper limit placed on the outbound
bandwidth of an instance to prevent unexpected high fees caused by traffic bursts.
- Log on to the ECS console.
- In the left-side navigation pane, choose .
- In the top navigation bar, select a region.
- Use one of the following methods to modify the peak bandwidths of instances:
- Modify the peak bandwidth of a single instance at a time
- Find the subscription instance whose peak bandwidth you want to modify and click Upgrade/Downgrade in the Actions column.
- In the Upgrade/Downgrade Wizard dialog box, select one of the following options and
click Continue:
- Upgrade: allows you to modify the peak bandwidth or change the billing method for network
usage to pay-by-bandwidth.
- : allows you only to modify the peak bandwidth.
- Modify the peak bandwidths of multiple instances at a time
- Select the subscription instances whose peak bandwidths you want to modify. In the
lower part of the Instances page, choose .
- In the dialog box that appears, select Modify Peak Bandwidth Value and click Continue.
- On the page that appears, specify a new peak bandwidth in the Bandwidth section.
When you modify the peak bandwidths of multiple instances at a time, instances are
filtered out if they are not associated with a public IP address or if they do not
use the pay-by-traffic billing method for network usage. You can continue to modify
peak bandwidths for only the eligible instances, as shown in the following figure.

Note
- If you downgrade the peak bandwidth of an instance in the classic network to 0 Mbit/s,
the public IP address of the instance is retained. If you downgrade the peak bandwidth
of an instance in a VPC to 0 Mbit/s, the public IP address of the instance is released.
- You can select Pay-By-Bandwidth to change the billing method for network usage to pay-by-bandwidth and specify a
bandwidth.
- Read the notes. Read and select ECS Service Terms.
- Click the button in the lower part of the page and perform the subsequent operations
as instructed.
Note
- If you change the billing method for network usage from pay-by-traffic to pay-by-bandwidth,
you must pay for the fixed bandwidth upfront.
- The first time you upgrade the peak bandwidth of an instance in the classic network
from 0 Mbit/s to a non-zero value, you must restart the instance by using the ECS
console or by calling the RebootInstance operation for the new configurations to take effect.