cl_updaterate - This is the number of packets (per second) of updates that you request from the server. Since our servers are 66 tic server, its best to set it to 66.
cl_cmdrate - This is the number of command packets sent to the server (per second). Set it to 66 (for the same reason as updaterate)
rate - This sets the data transfer speed. The higher the better. This one is a bit tricker to set because it depends on your internet connection. Try a high number (100000 for example) at first and see if you get choke/loss (using net_graph 3).
I attached my autoexec because I remember writing down explanation on some netcode commands.