First off, let’s start with defining AWS data transfer. It refers to the movement of data in and out of AWS services over the internet or other networks, or between different AWS services, such as moving data from an Amazon S3 bucket to an Amazon EC2 instance. In other words, it includes various scenarios, like transferring data from on-premises or other cloud platforms to AWS services, or vice versa. AWS data transfer also occurs when transferring data between different AWS services, whether it’s happening between different Availability Zones, or within the same AZ. Just a refresher: Availability Zones are physically separate, isolated data centers within certain AWS regions; they are engineered to be isolated from failures in other Availability Zones.
How much does the AWS data transfer cost?
Why is it such a big deal to know the ins and outs of AWS data transfer when it comes to AWS cloud cost management? It’s important because, if overlooked and not paid enough attention to, data transfer costs can add up, quickly representing a significant portion of a company’s overall AWS bill. And only by getting an idea of how exactly data is transferred between your clouds, different availability zones and/or AWS services you’re using, you can make more informed decisions about how to optimize your data transfer usage and ultimately reduce your overall cloud costs.
Let’s start with a caveat here: there’s a common misconception that all data transfer within an AWS availability zone is free of charge, but no, it’s not. When VPC peering connection is involved, it still incurs charges from AWS.
Generally speaking, the cost of AWS data transfer varies depending on the parameters and aspects we talked about above: the amount of data being transferred (there is a non-linear data-price dependence), specific AWS services involved, and the distance the data is moving. As a rule of thumb, data transfer within an AWS region is less expensive than transferring data across regions, and data transfer between different AWS services within the same availability zone is typically cheaper than transferring data between availability zones.
Here are some of the most common examples of AWS data transfer costs:
- Data transfer between two Amazon EC2 instances in the same availability zone is free (if there’s no VPC peering connection).
- Data transfer between two Amazon EC2 instances in different availability zones within the same region is charged at $0.01 per GB.
- Data transfer between an Amazon EC2 instance and an Amazon S3 bucket in the same region is charged at $0.09 per GB.
- Data transfer between an Amazon EC2 instance and an on-premises system over an AWS Direct Connect connection is charged at $0.01 per GB.
- Data transfer between an Amazon EC2 instance and another cloud provider (such as Microsoft Azure or Google Cloud Platform) is charged at $0.02 per GB.
- Data transfer between an Amazon S3 bucket in the US East (N. Virginia) region and an Amazon S3 bucket in the EU (Ireland) region is charged at $0.01 per GB.
- Data transfer between an Amazon EC2 instance in the US East (N. Virginia) region and an Amazon S3 bucket in the Asia Pacific (Tokyo) region is charged at $0.19 per GB.
These examples of costs are given for your consideration so that you have a general idea of how much you’re going to pay based on your cloud data transfer usage patterns. Anyway, the exact cost will depend on the specific AWS services and scenarios involved.
How to minimize network traffic costs between regions and availability zones
There are a few ways you can minimize network traffic costs between regions and availability zones in AWS:
- Use Amazon Elastic Block Store (EBS) optimized instances, which are EC2 instances that are optimized for EBS I/O, to improve the performance of your network traffic and, as a result, reduce the amount of data transferred over the network. Also, EBS-optimized instances can help your workloads run more efficiently, which will reduce the amount of time that your workloads spend transferring data over the network. Finally, dedicated, high-throughput, low-latency network connections ensured by EBS-optimized instances help reduce the amount of time that your workloads spend reading and writing data to and from an instance.
- Use Amazon S3 Transfer Acceleration, which uses the Amazon CloudFront global edge network to accelerate the transfer of data to and from Amazon S3. The CloudFront edge network works in a way that results in reduction of the distance that data needs to travel and the number of “hops” it needs to make between your users and your S3 bucket. As a result, the amount of time that data spends in transit will also decrease. Besides, S3 Transfer Acceleration caches frequently accessed data at edge locations closer to your users, which additionally reduces the amount of data that needs to be transferred over the network.
- Use Amazon Direct Connect, which is a dedicated network connection between your on-premises environment and AWS, to reduce data transfer costs and improve performance. Being a dedicated network connection, Direct Connect reduces the amount of time that data spends in transit between your on-premises environment and AWS and at the same time helps minimize congestion on the public internet.
- Use AWS data transfer pricing discounts. AWS offers several types of volume-based discounts that are reductions in the fees that you pay based on the amount of data that you transfer. For example, there’s a volume-based discount of 50% for the first 10 TB of data transferred per month between AWS services in different regions.
Will this be enough? Aren’t there any hidden network transfer costs?
Remember that, when it comes to the cloud, there always will be hidden costs, and those related to data transfer are no exception. Such hidden costs can include things like the time and effort required to manage and optimize your network traffic, the impact of network bottlenecks on the performance of your workloads, and lost or corrupted data due to network errors or failures.
Hidden data transfer costs are difficult to identify and measure, which makes it challenging to manage and minimize them. However, if you stick to the above advice, you’ll be able to substantially reduce hidden data transfer costs by tackling the root cause.
And if you opt for third-party tools like OptScale, you can minimize hidden data transfer costs even more by getting access to additional functionality that is not available with native AWS services.
For example, OptScale provides geo and network traffic cost map, which shows accumulated expenses for paid network traffic between cloud regions and external services. This will ensure there are no hidden costs associated with it, including lost IT team momentum and productivity, revenue, and customer satisfaction.
Free cloud cost optimization for a lifetime
Hystax OptScale offers the first-ever open source FinOps & multi-cloud cost management solution that is fully available under Apache 2.0 on GitHub → https://github.com/hystax/optscale
👆🏻 Find best practices + helpful tips to reduce your AWS bill → How to identify and delete orphaned and unused snapshots.