IPsec Site-to-Site VPN Low Performance

[tejas.designer07]

Hi,

I have followed the following article to setup site-to-site IPsec VPN:
https://docs.opnsense.org/manual/how-tos/ipsec-s2s.html

I am able to successfully establish connection between both sites. I am getting very low performance(25mbps on a 1 gbps internet connection between both sites.) using iperf. I have also validated that AES-IN is enabled in the BIOS. I also noticed that the CPU usage doesn't increase even after file transfer has been initiated.

I am unable to detect the problem, please guide me through issue. Thanks in advance.