Does PFSense modify TCP window sizes?

[biogoon]

Dear experts,

I'm working to improve speeds over a high latency network between our east and west coast offices. On the clients, I'm experimenting with larger tcp window sizes over our site-to-site OpenVPN connection, and also direct between our public IPs. PFsense boxes serve as our border router, nat, and openvpn servers at both sites.

My question is: does PFSense modify the tcp windows sizes? There is a system tunable about tcp window sizes, but I'm wondering if that is just for the system itself, and not the packets being routed through the system.

Thanks much!

Jordan

[phil.davis]

TCP window size is a parameter at a higher layer that end-systems use to work out how much data to have outstanding in the pipeline before waiting/expecting ACKs to have come back. I played with this many years ago tuning continuous flows of a data acquisition process across a long link. TCP window size needs to be adjusted on the end-systems.