Yes, downloading files via COS (Cloud Object Storage) will incur extranet downstream traffic charges. COS is a cloud storage service that allows users to store and retrieve files in the cloud. When you download a file from COS, it is transferred from the cloud to your local device or another cloud service, which counts as extranet downstream traffic.
Extranet downstream traffic refers to the data that is transferred from the cloud service provider's network to an external network, such as the internet. This type of traffic is usually charged based on the amount of data transferred and the speed of the transfer.
For example, if you have a file stored in COS and you download it to your local computer, the data transferred from COS to your computer will be counted as extranet downstream traffic. The cost of this traffic will depend on the size of the file and the speed of the download.
To minimize extranet downstream traffic charges, you can consider using CDN (Content Delivery Network) acceleration, which can cache your files at edge locations closer to your users, reducing the amount of data that needs to be transferred from the cloud.
If you are using Tencent Cloud, you can leverage its CDN service to optimize your file downloads and reduce extranet downstream traffic charges. Tencent Cloud CDN offers a wide range of features and benefits, including high-speed content delivery, low latency, and secure access.