The clients tells the server what speed it likes to have. Gusanos defaults to 20 packets with 200 bytes each per second, making a total of ~4 kb/sec. If you want more, set higher values for NET_DOWN_PPS (packets per second) and NET_DOWN_BPS (bytes per packet). Set NET_DOWN_BPS to 490, that should give you about 10kb/sec. Increasing the PPS is not recommended, as this will increase the serverload when you are playing.