This topic describes the types of Internet bandwidth, billing methods, and examples on how to calculate bandwidth fees.

Types of public IP addresses

An ECS instance can access the Internet by using the following types of public IP addresses:
  • Assigned public IP address

    For your instance to use an allocated public IP address to access the Internet, select Assign Public IP Address when you configure the Internet bandwidth during instance creation. For more information, see Create an instance.

  • Elastic IP address (EIP)
    An EIP is a public IP address resource that you can purchase and use independently. It can be associated with an instance to access the Internet. For information about the differences between an EIP and an assigned public IP address, see Elastic IP addresses.
    Note EIPs can be associated with only VPC-type instances.

    For your instance to use an EIP to access the Internet, do not select Assign Public IP Address when configuring the Internet bandwidth when you create an instance. Instead, associate the purchased EIP with your instance. For more information, see Associate an EIP with an ECS instance.

Internet bandwidth types

Internet bandwidths are classified into outbound bandwidth and inbound bandwidth. Alibaba Cloud charges fees for only outbound traffic usage.
Type Description Example
Outbound bandwidth Bandwidth for outbound traffic from ECS instances Outbound bandwidth is consumed when your ECS instances provide external services or when you download the resources of your ECS instances through an FTP client.
Inbound bandwidth Bandwidth for inbound traffic to ECS instances Inbound bandwidth is consumed when you download resources from the public network to your ECS instances or when you upload resources to your ECS instances through an FTP client.

For information about the limits on Internet bandwidth of ECS instances, see Limits.

Billing methods

Alibaba Cloud does not charge any fee on intranet traffic. In the same LAN, no fees are charged for traffic between ECS instances or between ECS instances and other Alibaba Cloud products.

Internet bandwidth supports Pay-By-Bandwidth and Pay-By-Traffic billing methods. Bandwidth pricing varies by region. For more information about bandwidth pricing, see ECS pricing.
Note You can also purchase a data transfer plan to offset the network traffic. For more information, see Purchase a data transfer plan with one click.
  • Pay-By-Bandwidth: Fees are charged based on the bandwidth that you specify. Your actual outbound bandwidth will not exceed the specified bandwidth.
  • Pay-By-Traffic: Fees are charged based on the actual volume of outbound traffic in the unit of USD/GB. To prevent unexpected fees caused by traffic bursts, you can set a bandwidth limit for outbound traffic.

Billing example

This example uses the following Internet bandwidth information for your ECS instance:
  • Bandwidth billing method: Pay-By-Traffic
  • Usage period: 1 hour
  • Average bandwidth: 0.5 Mbit/s
  • Unit price: USD 0.1/GB
Note The unit price here is only for reference. Visit the Pricing page for price details.

The volume of the outbound traffic is (0.5 × 60 × 60)/1024/8 GB = 0.22 GB.

In this formula, 1024 is used to convert Mbit into Gbit, and 8 is used to convert Gbit into GB.

You must pay the following amount for the hourly traffic: 0.22 GB × 0.1 USD/GB = 0.022 USD.

This example assumes that the outbound traffic is 0.5 Mbit/s (the average bandwidth of the ECS instance).

To view the actual calculated fees, you can go to the Billing Management console and choose Usage Records to download the usage history of ECS.

Change the billing method

You must use different methods to change the billing method for outbound traffic based on how the ECS instance is billed.
Instance billing method Change the bandwidth billing method Method
Subscription From Pay-By-Traffic to Pay-By-Bandwidth Upgrade configurations of Subscription instances, the new billing method takes effect immediately.
From Pay-By-Bandwidth to Pay-By-Traffic
Pay-as-you-go From Pay-By-Traffic to Pay-By-Bandwidth Change Internet bandwidth, the new billing method takes effect immediately.
From Pay-By-Bandwidth to Pay-By-Traffic Change Internet bandwidth, the new billing method takes effect immediately.