Quizas te ayude esto.
56K Modem
cl_updaterate "20"
cl_cmdrate "30"
rate "(Mirar tabla)"
50000 BPS: rate "5500"
48000 BPS: rate "5200"
46000 BPS: rate "5000"
44000 BPS: rate "4800"
42000 BPS: rate "4500"
40000 BPS: rate "4300"
38000 BPS: rate "4100"
36000 BPS: rate "4000"
Sacado del FAQ
Saludos