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This article describes the Data Transfer Traffic usage difference between WAN Link Manager and WAN Zone report.
Go to Network > WAN Link Manager and click the Manage icon next to the IPv4 or IPv6 Gateway to view data transfer graphs related to that Gateway. These graphs give an insight into the volume of traffic passing through the selected gateway in terms of upload and download network traffic (in MB).
WAN Zone reports are generated under Monitor & Analyze - Application & Web - Show: User App risks & Usage.
Data Transfer Usages in WAN Link Manager shows Layer 1/ Physical level stats and can be compared against ISP data transfer.
WAN Zone is the logical entity that works at Layer 3. Based on the traffic passed from a specific firewall rule, the WAN zone graph is generated from the connection.
Below the statistics of WAN Link, Manager and WAN Zone reports explaining the reason for different Data Transfer traffic usages.
WAN Link Manager statistics:
WAN Zone Report statistics:
The below logical diagram would also explain the difference between WAN Link Manager and WAN Zone reports.