Thank you for posting this concern on this community space.
I have read your case scenario description and I would like to gather or share my 2 cents here below:
1-For instance, I have faced the same issue with latency as well. On the output, you will see that I have a P2S VPN and I found that the MTU value configured is not the standard which is 1500.
Adapter info below: PPP adapter vnet-southcentralus-xxxxx-xxx-001: Connection-specific DNS Suffix . : IPv4 Address. . . . . . . . . . . : 192.168.254.2 Subnet Mask . . . . . . . . . . . : 255.255.255.255 Default Gateway . . . . . . . . . :
2-Then, you can look at the MTU value:
3- As per public documentation, there is a default behavior that is relevant to know which is:
- All data packets will be fragmented at 1400 as MTU value permitted.
- If on TCP session is observed TCP-Out-of-Orders packets sequence, Port Reused behavior and so on... Well, they will be dropped.
- If you want to enhance or speed up your data session, you can either use an NVA (Network Virtual Appliance) or work on the MSS value on TCP sessions.
- You can modify the MTU value along the routing path.
- Please direct your self to the following URL: https://learn.microsoft.com/en-us/azure/virtual-network/virtual-network-tcpip-performance-tuning
- You can change the listening ports and among others.
- Furthermore, review the MTU value at the OS level on your server/vm.
- Finally, you can reset the VPN gateway and get better results with your latency concern.
Looking forward to your feedback,
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