WAN Optimization Calculator
Estimate effective WAN bandwidth after deduplication and compression from WAN optimization appliances.
Inputs
e.g. 1.5 means redundant data transfer is cut to 1/1.5 of original
Effective Bandwidth (perceived throughput)
150.0Mbps
Combined Optimization Ratio
3.00
Effective Bandwidth Gain
200.0%
Step by step
Values used
Actual Link Bandwidth = 50 Mbps; Deduplication Ratio = 1.50; Compression Ratio = 2
Effective bandwidth
effective_bw = actual_bw × dedup_ratio × compression_ratio
Effective Bandwidth (perceived throughput)
= 150.0 Mbps
Combined Optimization Ratio
= 3.00
Effective Bandwidth Gain
= 200.0
How it works
WAN optimization appliances increase the effective, perceived throughput of a fixed physical link by reducing how much data actually needs to cross it — deduplication avoids re-sending data blocks the remote end already has cached, and compression shrinks the data that must be sent. These two techniques stack multiplicatively: a link that only physically carries the actual bandwidth can behave, from an application's perspective, as if it carries dedup_ratio × compression_ratio times that bandwidth for suitable (compressible, redundant) traffic patterns.
Formula
Effective bandwidth
effective_bw = actual_bw × dedup_ratio × compression_ratio
Frequently Asked Questions
Does WAN optimization increase the physical link speed?
No — the underlying physical bandwidth is unchanged. WAN optimization reduces the volume of data that must actually cross the link for a given amount of useful data delivered, which produces the same practical effect as a faster link for compatible traffic, but doesn't help traffic types that don't compress or deduplicate well (e.g. already-compressed video, encrypted traffic).
Why do dedup and compression ratios vary so much by traffic type?
Deduplication benefits most from repetitive data patterns — file shares, backups, and VDI traffic often see high dedup ratios because similar blocks recur across transfers. Compression benefits most from data with statistical redundancy — text, logs, and uncompressed formats compress well, while already-compressed or encrypted data barely compresses further, sometimes even growing slightly.
What traffic doesn't benefit much from WAN optimization?
Encrypted traffic (VPN tunnels, TLS/HTTPS, already-encrypted backups) looks like random noise to both deduplication and compression algorithms, so it typically sees minimal benefit unless the WAN optimizer can inspect it before encryption or the endpoints support optimization-aware encryption.