Connection made be simple or wvdial for ppp connections

Small test for UMTS dongle (huawei e352b, seriously, Huawei :D) shows that wvdial is a pretty good for quick connections via 3G modems. Also, it has a lot of useful options.

So, before made connection we need to install usb-modeswitch (usb_modeswitch in gentoo) and (in some distros - usb-modeswitch-data).
It has udev rules and binary file, all this will switch usb dongle from usb-storage (or something else?) into usb-modem mode.

Next, run wvdialconf to generate config file. wvdialconf will send commands to dongle and try to write optimal parameters in /etc/wvdial.conf.

Sure, if you know correct options for modem - just write it to /etc/wvdial.conf.

Below correct config file for Utel (ukrainian operator)

[Dialer Defaults]
Init1 = ATZ  
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2  
Init3 = AT+CGDCONT=1, "IP","3g.utel.ua"  
Modem Type = USB Modem  
Baud = 460800  
New PPPD = yes  
Modem = /dev/modem  
ISDN = 0  
Phone = *99#  
Username = 1  
Password = 1  
Stupid Mode = 1  
Auto Reconnect = on

Also, maybe /dev/modem doesn't exist. Then create symlink from /dev/ttyUSB0, or set /dev/ttyUSB0 in wvdial.conf.