What do you need to have?

• LTE USB modem - Alcatel Link Key IK40
• micro SIM card
• access to the SSH

In this article I will show you how to configure USB modem Alcatel Link Key IK40.
Also I will also show you how to have mobile broandband as backup connection (failover).

Information about used LTE USB modem (which you can find by using SSH):

root@turris:~# lsusb
Bus 001 Device 005: ID 1bbb:0195 T & A Mobile Phones

In PuTTY or Terminal log into your router to SSH and install these packages:

opkg install kmod-usb-net-rndis usb-modeswitch

Protocol RNDIS isn't supported in the advanced configuration interface called LuCI.

You have 3 options.
1. In Windows you can use program WinSCP.
2. You can use vim
3. UCI.

Before you will continue you would need to know APN. Your's mobile operator should tell you, what needs to be there. Usually it is something like internet.

Open a file /etc/config/network and now you will need to change ipaddr to 10.10.10.1

It should looks like this (but remember this article was made on Turris 1.x and ifname could be different!)

config interface 'lan'
	option ifname 'eth0 eth1'
	option force_link '1'
	option type 'bridge'
	option proto 'static'
	option netmask '255.255.255.0'
	option ip6assign '60'
	option ipaddr '10.10.10.1'

And to the end of this file you will need to add

config interface 'lte'
	option ifname 'usb0'
	option proto 'dhcp'
	option apn 'internet'

Save it.

In PuTTY or Terminal log into your router to SSH and copy&paste these rows:

uci set network.lte=interface
uci set network.lte.ifname='usb0'
uci set network.lte.proto='dhcp'
uci set network.lte.apn='internet'
uci commit

Go to LuCI interface (by default should be located on http://192.168.1.1/cgi-bin/luci ) → Network → Firewal

Edit 2nd zone (should be wan) and check there lte interface.

Click Save & Apply

Now you should see how KB moves in RX and TX. You can also check it by disconnecting WAN cable.

Open file /etc/config/firewall and locate config zone, where under it should be: option name 'wan'

If there isn't option network then copy&paste like it is below. If there is option network then you would need to add there interface lte as it is below.

config zone should be same like this one

config zone
	option name 'wan'
	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	option masq '1'
	option mtu_fix '1'
	option network 'lte wan wan6'

When connection doesn't work you need to restart router.

Can be found on this address http://192.168.1.1

Please go here, where it is explained: https://www.turris.cz/doc/en/howto/multiwan

When you have inserted microSD card to LTE modem, which is connected to the Turris router, you will need to check if router sees microSD card in LTE modem.

I will use SSH:

blkid

You should see similar output as I do.

root@turris:~# blkid
/dev/mtdblock3: TYPE="squashfs"
/dev/mmcblk0: PTUUID="3fee9afa" PTTYPE="dos"
/dev/mmcblk0p1: SEC_TYPE="msdos" UUID="3462-1AE5" TYPE="vfat" PARTUUID="3fee9afa-01"
/dev/mmcblk0p2: UUID="1acf499c-1067-4fe1-b1b7-af7dc884f7ae" UUID_SUB="fd211a80-da78-49fc-a7c2-f2ed2b840301" TYPE="btrfs" PARTUUID="3fee9afa-02"
/dev/sda1: UUID="ED37-A894" TYPE="exfat"

Now we can see that microSD mounted is detected as dev/sda and their type is: exfat

By this command you can format it to ext4 file system

mkfs.ext4 /dev/sda1

You can also use LuCI to add new mount point in System tab.

(Turris 1.x owners can't add it through LuCI and will need to mount it manually)

or you can mount it manually

If you would like to have microSD card in folder sd, which will be located in /mnt First you will need to create folder sd in /mnt

mkdir /mnt/sd

mount /dev/sda1 /mnt/sd

Now I will show you how to verify, if sd card is mounted, how we wanted.

root@turris:~# df -h

Filesystem                Size      Used Available Use% Mounted on
/dev/mmcblk0p2          119.1G    136.5M    118.0G   0% /
tmpfs                  1011.5M      1.7M   1009.8M   0% /tmp
tmpfs                   512.0K      4.0K    508.0K   1% /dev
/dev/sda1               116.8G     60.0M    110.8G   0% /mnt/sd

— Josef Schlehofer 2017/11/09 00:30