When your gateway writes data to AWS you will be charged at a flat rate of $0.01 per GB of data written to AWS up to a monthly maximum of no more than $125 per gateway. There is no charge for reading data from AWS. Since the gateway performs caching, bandwidth optimization, and, for Volume and Tape Gateways, compression, the amount of data written to AWS may be less than the amount of data written to the gateway by your application. You can monitor the amount of data written by your gateway to AWS through the provided Amazon CloudWatch metrics and you can configure bandwidth limits on your gateway to manage your costs.