how to make sysctl changes on startup?

If nobody replies, I have notes on what file to make to read that at startup, but it's at work, so tomorrow on that one.

Or you could just make a Script for Startup/login Items.

You can use some 3rd party apps to make changes to tcp values.

One app that springs to mind is Mac Pilot

I am not sure this app will help but it just sprang to mind.

Create a file named sysctl.conf in your local /etc folder
This needs again to be done as root!
Go to the command line, become root and fire up your preferred editor (vi) by typing vi /etc/sysctl.conf

Put the following into the newly created file, (shown for example only, but where your keepalive goes),

net.inet.tcp.delayed_ack=0
net.inet.tcp.mssdflt=1460
net.inet.tcp.newreno=1

and save the file. The file rights must be set to: owner root:wheel and -rw-r--r-- please make sure by typing ls -al /etc/sysctl.conf on the command line and if not change it by running chown root:wheel /etc/sysctl.conf and chmod 0644 /etc/sysctl.conf from the command line.

Fabulous! 🙂