multiple ppp usb on linux

reset.sh

#!/bin/bash

reset_iptables() {
    iptables -F
    iptables -X
    iptables -t nat -F
    iptables -t nat -X
    iptables -t mangle -F
    iptables -t mangle -X
    iptables -P INPUT ACCEPT
    iptables -P FORWARD ACCEPT
    iptables -P OUTPUT ACCEPT
}

reset_routes() {
    ip route flush table main

    echo "ip route show"
    echo ">"
    ip route show

    ip route flush cache

    echo "ip show cache"
    echo ">"
    ip route show cache
}

init_config() {
    groupadd wheel
    declare -a users=('user_vina', 'user_mobi') #...
    declare -a interfaces=('eth0', 'wlan0') #...

    for u in $users; do
        useradd -G wheel -s /bin/bash $u
    done

    # FOR those rt_tabless

    sudo bash -c 'cat <<EOF >/etc/iproute2/rt_tables
    #
    # reserved values
    #
    255     local
    254     main
    253     default
    0       unspec
    #
    # local
    #
    #1      inr.ruhep
    200 user1
    201 user2
EOF'

    iptables -A OUTPUT -m owner  --uid-owner 'user_vina' -j MARK --set-mark 0x1
    iptables -A OUTPUT -m owner  --uid-owner 'user_mobi' -j MARK --set-mark 0x2


    if [[ `ip rule list | grep -c 0x1` == "0" ]]; then
        ip rule add from all fwmark 0x1 lookup 'user_vina'
    fi
    ip route replace default via 192.168.1.1 table user_vina
    ip route append default via 127.0.0.1 dev lo table user_vina

    if [[ `ip rule list | grep -c 0x2` == "0" ]]; then
        ip rule add from all fwmark 0x1 lookup 'user_mobi'
    fi
    ip route replace default via 192.168.1.1 table user_mobi
    ip route append default via 127.0.0.1 dev lo table user_mobi

    ip route flush cache
}



sudo_wheel_group() {
    sudo bash -c 'cat <<EOF >>/etc/sudoers
    %wheel ALL=(ALL) NOPASSWD: ALL
EOF'
}


reset_iptables
reset_routes
sudo_wheel_group
init_config

wvdial.conf

[Dialer Defaults]
Init = ATZ
Init = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = USB
Modem Baud = 115200
Modem = /dev/ttyUSB0
Phone = *99#
Username = ''
Password = ''
Stupid Mode = 1