This topic describes the considerations that you must pay close attention to when Internet Small Computer System Interface (iSCSI) gateways transmit data.
Data is uploaded to iSCSI gateways in slices. You can customize the slice size. The default slice size is 32 KB. On-premises iSCSI gateways cache data for accelerated read requests based on data access frequency. When an on-premise iSCSI gateway needs to read infrequently accessed data, but it cannot find the data on the client, it downloads the data from the associated Object Storage Service (OSS) bucket. This download process incurs outbound traffic.