Site-to-Site VPN connections

  • Site to site VPN connection can be established immediately

  • Site to site VPN connection is cheaper (compared to AWS Direct Connect)

  • A single VPN tunnel still has a maximum throughput of 1.25 Gbps

  • Use AWS Transit Gateway to scale an AWS Site-to-Site VPN throughput beyond a single IPsec tunnel’s maximum limit of 1.25 Gbps limit

  • To resolve slower VPN connection, use a transit gateway with equal cost multipath routing and add additional VPN tunnels

  • Transit Gateway enables you to scale the IPsec VPN throughput with equal cost multi-path (ECMP) routing support over multiple VPN tunnels

https://aws.amazon.com/blogs/networking-and-content-delivery/scaling-vpn-throughput-using-aws-transit-gateway/