set connection to a modem

[s m]

hello guys,

i want to connect my freebsd system to modem and configure it via my
freebsd. i thought that i should change /etc/ttys file to set speed and
other configuration. in order to check if i am right or not, i comment ttyu
line in ttys file and expect the modem got disconnected but the modem still
works and can access to it.

i googled and found that there are three files in /etc that we can edit
them to configure our devices: /etc/ttys, /etc/gettytab and
/etc/rc.d/serial.sh. moreover we can edit init file for each device in /dev
to set default speed and other configuration by stty command.

now i am confused and don't know which file i should edit to set speed and
flow control and other setting to have a connection to my modem. i mean
from which file i can configure my connection? i know it's too easy but
please clear it for me.

yours,
sam