ISC2 Systems Security Certified Practitioner (SSCP) Practice Question

Byte-level data deduplication (often called data streamlining or data redundancy elimination) stores previously transferred byte patterns in a local disk cache on each side of the WAN. When the appliance detects that a block of data has been sent before, it substitutes a small reference instead of retransmitting the entire block, dramatically reducing the volume of data on the wire. Standard compression can shrink individual files but still sends all data for every transfer; TCP window scaling only improves utilization of available bandwidth and does nothing to eliminate duplicate payloads; link aggregation simply adds physical capacity rather than optimizing existing traffic; and QoS marking changes priority but not the amount of data sent. Therefore, deduplication offers the greatest bandwidth savings for nightly transfers of largely unchanged files.