Amazon Web Services (AWS) network costs refer to the cost associated with transferring data in and out of the AWS network. In short, it’s what AWS charges you to transfer data either:

• Between the Internet and AWS.
• Between AWS services, such as Amazon S3 and Amazon EC2.

Network costs vary based on geographical region, source location, and target location. Other factors that determine the cost include AWS resources, AWS services, and the volume of data you want to transfer.

One of the biggest culprits of hidden transfer costs is applications or services that retrieve a significant amount of data from S3. While each request may only cost a small amount, these costs add up quickly at scale.

Examples include applications that are consistently having a two-way dialogue with the Internet. A good example is disaster recovery services that replicate business-critical data regularly to secondary AWS regions.

AWS network costs can be overwhelming to manage. But they can be punitive if you take your eye off the ball. One of the easiest ways to keep costs low is to restrict transfers within the same AWS availability zone or AWS region. But this isn’t always possible, so you need to understand the cost implications of every decision you make.

Here’s a breakdown of the structure of data transfer charges on AWS.

Data Transfers Out of or into AWS Regions

AWS doesn’t charge for data transfers into AWS regions from the Internet. It’s completely free. However, transferring data out to the Internet from AWS regions is a chargeable service. You receive a bill based on your region at a tiered data transfer rate.

AWS calculates your data transfer out costs every month. To do this, AWS applies relevant rate tiers to aggregate data transfer usage across AWS resources and AWS services in the region.

AWS has a Free Usage Tier. New customers can receive up to 15 GB of free data transfer out every month aggregated across all AWS services and regions. But the free usage tier doesn’t apply to AWS GovCloud. The Free Usage Tier runs for the first year.

Any data you transfer from the local AWS region to another region incurs a charge at the source region data transfer rate.

AWS Direct Connect provides an alternative to using the Internet to connect your on-premises deployment to your AWS cloud deployments. Data transfers emanating from AWS Direct Connect locations going into AWS regions is free of charge. Transferring data from AWS regions to AWS Direct Connect locations incurs a charge based on the AWS region.

Data Transfers into or Out of AWS Edge Locations

Edge locations are AWS data centers located worldwide and connected to AWS regions via an AWS-managed backbone network. Typically, you use edge locations to provide end-users with a faster and more reliable content delivery experience.

Transferring data into your AWS edge location from the Internet is free. However, transferring data out of AWS edge locations to the Internet is a chargeable service. You’ll receive a bill based on a region-specific, tiered data transfer rate.

Transferring data into AWS edge locations from all AWS regions is free. However, transferring data out of AWS edge locations to origin in AWS regions is a chargeable service. You’ll receive a bill with a region-specific data transfer rate.

To accelerate transfers between AWS regions and AWS edge locations, AWS provides three additional services:

• AWS Global Accelerator
• Amazon S3 Transfer Acceleration
• AWS Site-to-Site VPN with Acceleration

Each service has a separate charge. This charge is in addition to the standard data transfer costs for data transferred out of, into, and within AWS.

Data Transfers within an AWS Region

AWS charges data transfers between its services within a region. The charges depend on whether you’re transferring data across availability zones or within availability zones.

AWS doesn’t charge if you’re transferring data within the same region and the same availability zone and use a private IP address. However, if you’re transferring data within the same region but in a different availability zone, you will receive a bill.

AWS Network Cost Optimization Tips

We’ve covered the chargeable and free transfers across each data transfer category. Now, we need to look at how you can apply this to reduce your organization’s AWS bill.

1. Understand Your Current Data Transfer Spend

Start by measuring everything. Explore your historical cost patterns and visualize your data transfer spending habits and trends. Dig deep into EC2 service-line items to get a clear picture of where you stand.

2. Architect Your AWS Environment to Optimize Data Transfers

Build out your environment with AWS network cost optimization in mind. Do the following:

• Keep data within the same availability zone.
• Keep data within the same region.
• Use less expensive regions where necessary.

Conclusion

Failure to take AWS data transfer costs into account when calculating AWS TCO (total cost of ownership) can be disastrous. Use the nOps cloud management platform to gain total visibility into your AWS environment and avoid AWS cloud sticker shock.