Size OCI Site-to-Site VPN tunnels for a throughput target and price the egress, since the VPN service itself is free.
IPSec throughput is bounded per tunnel, so meeting a target means running several tunnels in parallel and adding capacity for the one that will eventually fail. Oracle provisions two tunnels per Site-to-Site VPN connection and charges nothing for the service, which leaves outbound data transfer above the free 10 TB as the only OCI line on the bill. A single tunnel silently caps a migration or replication stream at a few hundred Mbps no matter how fast the internet circuit is, and an active-passive design needs twice the tunnels for the same usable throughput. Above a few hundred Mbps sustained, FastConnect is usually the better answer — confirm data transfer prices in the Oracle Cloud cost estimator for your region.
OCI VPN
tunnels = ceil(required Mbps ÷ per-tunnel Mbps), plus one spare for active-active or doubled for active-passive; connections = ceil(tunnels ÷ 2) because each IPSec connection provides two tunnels.
tunnels = ceil(required Mbps ÷ per-tunnel Mbps), plus one spare for active-active or doubled for active-passive; connections = ceil(tunnels ÷ 2) because each IPSec connection provides two tunnels. IPSec throughput is bounded per tunnel, so meeting a target means running several tunnels in parallel and adding capacity for the one that will eventually fail. Oracle provisions two tunnels per Site-to-Site VPN connection and charges nothing for the service, which leaves outbound data transfer above the free 10 TB as the only OCI line on the bill.
A single tunnel silently caps a migration or replication stream at a few hundred Mbps no matter how fast the internet circuit is, and an active-passive design needs twice the tunnels for the same usable throughput. Above a few hundred Mbps sustained, FastConnect is usually the better answer — confirm data transfer prices in the Oracle Cloud cost estimator for your region.
This calculator takes 8 inputs: Throughput required, Throughput per tunnel, Redundancy design, Price per IPSec connection-hour, Billed hours per month, Outbound traffic over the VPN, Free egress allowance, Egress price per GB above the allowance. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.