Azure VPN Gateway Scaling VPN Bandwidth in Site to Site Connections

Question

Hello.

I am considering Azure VPN connection.
I want the same configuration as the AWS document in the link below.
[https://aws.amazon.com/ko/blogs/networking-and-content-delivery/scaling-vpn-throughput-using-aws-transit-gateway](https://aws.amazon.com/ko/blogs/networking-and-content-delivery/scaling-vpn-throughput-using-aws-transit-gateway/

)

I want to increase the bandwidth of a Site to Site VPN connection to a single on-premise site.
In the following documents, it is guided that it is possible using Equal-cost multi-path routing.

However, there is no word that bandwidth can be scaled.
https://learn.microsoft.com/en-us/azure/vpn-gateway/vpn-gateway-highlyavailable#multiple-on-premises-vpn-devices

I can check what is possible in other questions.
But I can't find a document that tells me how.

https://learn.microsoft.com/en-us/answers/questions/390147/multiple-site2site-vpn-bewteen-virtual-wan-hub-and

Thank you.

Answer 1

@아롬 황

Welcome to the Microsoft Q&A Platform. Thank you for reaching out & I hope you are doing well.

I understand that you would like to know the maximum bandwidth you can achieve in a VPN Gateway Connection.

Points to Note

• Bandwidth of a VPN Gateway is different from the Bandwidth of an individual Tunnel in the Gateway.
• Aggregate Throughput Benchmark of VPN Gateway depends on the SKU
• While, Throughput observed per tunnel depends on the SKU + Algorithms used (Refer to "bandwidth and packets per second throughput per tunnel" under Gateway SKUs
• 

Now, let's discuss how having two tunnels can increase your throughput.

• Here, you create two tunnels to your OnPremises.
• So, the total throughput becomes two times individual Tunnel throughput or the maximum bandwidth supported by your SKU (whichever is the least one of them)
• From Azure side, as long as same address ranges are advertised from both the tunnels, the traffic distribution uses ECMP and each TCP or UDP flow will follow the same tunnel or path.
• You must also configure ECMP for your On Premises depending upon your device vendor so you can distribute traffic equally.

Please let me know should you require additional context on this.

Thanks,

Kapil

---

Please don’t forget to close the thread by clicking "Accept the answer" wherever the information provided helps you, as this can be beneficial to other community members.