4G Router: ZBT WE826-T & Sierra Wireless MC7455 & Sim

Hi ! I'am a french guy new on the router and modem stuff and on this forum but I enjoy this.

ZBT WE826-T (aliexpress)
Sierra Wireless MC7455 (aliexpress)

-First I have flashed with OpenWRT (lastest version)
-It detect the modem Sierra MC7455

  • I have set up the APN and the PIN
  • but I don't see my Sim

So, I have flashed with ROOter GoldenOrb
and it's the same thing, I see the modem but not the Sim, I don't have connection to the Internet ..

I was belived it's work on the go but it did'not

Many questions:

My 4G connection is bad, I live in a rural area, so how can I verify if it''s connected to the Internet ?

I have saw there is a modem configuration with AT command , it is necessary ?

Can it work on the go without this ?

Thanks a lot

Ps : sorry for my english ..

but I cant' connect the Internet, I don't see my Sim

Il y a une documentation en français ici:

merci je l'ai déjà lu , je me suis inspiré de cet article pour réaliser ce routeur.. :wink:

J'ai réussi la connection semble t-il mais maintenant je ne parviens toujours pas à acceder à des sites

Est ce qu'il faut régler le firewall ? si oui comment ?

J'ai un SNR de -46 par là .. je crois savoir que c'est un bon ratio mais bon pourtant toujours pas réussi à me connecter ..

Network > Diagnostic > Ping = bad adress

Voilà un peu de précisions

Merci Ă  toi

I have to config the firewall ? If yes, how can I do it ?

I have a SNR of -46 but I can't reach any site

Network > Diagnostic > Ping = bad adress

thanks for support :slight_smile:

Can you post your system log from booting, the section from ******* Begin modem detection******
J'ai le mĂȘme modem/router sur un SIM SFR-Red.
J'ai desactivee le SIM pin, mise a jour le modem firmware avec ce guide ici Sierra Modems et metre le modem en mode MBIM
(désolé pour mon Francais, Je suis Anglais)

What answer do you get from the following command

qmicli -d /dev/cdc-wdm1 -p --dms-uim-get-state

The response should be something like

"[/dev/cdc-wdm1] UIM state retrieved:
State: 'initialization-completed'"

This might help you if the SIM-card is present:

qmicli -d /dev/cdc-wdm0 -p --wds-set-autoconnect-settings=enabled
udhcpc -q -f -n -i wwan0

Or (if youre device is cdc-wdm1)

qmicli -d /dev/cdc-wdm1 -p --wds-set-autoconnect-settings=enabled
udhcpc -q -f -n -i wwan1

Best regards !

Mon May  4 00:00:48 2020 : /dev/ttyUSB2 AT+CFUN=1
Manufacturer: Sierra Wireless, Incorporated
Model: MC7455
Revision: SWI9X30C_02.11.03.22 r6782 CARMD-EV-FRMWR2 2016/08/24 15:18:59
ESN: 12813082449, 80C79F51
FSN: LQ750486860310
Mon May  4 00:00:49 2020 : /dev/ttyUSB2 AT!SELRAT?
!SELRAT: 00, Automatic
Mon May  4 00:00:50 2020 : /dev/ttyUSB2 AT+CIMI
Mon May  4 00:00:52 2020 : /dev/ttyUSB2 AT+CRSM=176,12258,0,0,10
+CRSM: 144,0,"98330111814117864935"
Mon May  4 00:00:54 2020 : /dev/ttyUSB2 AT+COPS=0
+CME ERROR: SIM failure
Mon May  4 00:00:55 2020 : /dev/ttyUSB2 AT+CGDCONT=?
+CGDCONT: (1-24),"IP",,,(0-2),(0-4),(0-1),(0-1)
+CGDCONT: (1-24),"PPP",,,(0-2),(0-4),(0-1),(0-1)
+CGDCONT: (1-24),"IPV6",,,(0-2),(0-4),(0-1),(0-1)
+CGDCONT: (1-24),"IPV4V6",,,(0-2),(0-4),(0-1),(0-1)
Mon May  4 00:00:56 2020 : /dev/ttyUSB2 AT+CGDCONT?;+CFUN?
+CGDCONT: 1,"IP","sl2sfr","",0,0,0,0
+CFUN: 1
Mon May  4 00:00:59 2020 : /dev/ttyUSB2 AT+CGDCONT=1,"IPV4V6","sl2sfr";+CFUN=0;+CFUN=1
Mon May  4 00:01:13 2020 : /dev/ttyUSB2 AT+CMGS=?;+CMGL=?;+CMGR=?

Thanks for this great documentation ! If I understand there is no way to get it work without AT command ?
the problem is : I don't have the miniPCIE to USB connector ..

There isn't any package required to get it work ?

What about the console AT in the interface ?

(remember, I am on ROOter GoldenOrb now, but I can go back on Openwrt.. )

then better ask in their forum

OOOOH it's amazing !! I look I have send this post with the router connection !!

I'm an idiot .. it was a vpn problem on my computer, but I can tell you my setup ..


I don't now if I am on 4G or 3G :confused:

The modem is up using ppp serial mode. The MC7455 has different options for communication protocols between the router and the modem, ppp serial is a legacy protocol that has limited transfer speed between the modem and the router. The newer protocols are QMI and MBIM both of which are supported by openwrt. My guess is that you are connected to LTE but using ppp serial protocol.
If you want to use openwrt 19.07 I would recommend using the package modemmanager to set up the modem.
I am using ROOter firmware on my gateway device as it will default to QMI mode, and the modem debug information is very usefull when setting up the system in terms of signal strength measurements, it helps figure out if different antennas are needed, the bands in use, tower information etc.
Have a look at this modemmanager and this qmi how to and this has been useful to me ANFR for locating my nearest tower and the bands available.
I have been running this setup for 2 years and I can honestly say ROOter firmware has been fantastic as it deals with reconnecting very well and has readily available debug information for working out how to get the best connection. My speeds vary with tower loads but I rarely drop below 50mbps DL and I see the maximum 100mbps that the we826 is capable of.

1 Like

This info is very helpful.
One question for you, is it possible to repair IMEI for this modem, any info you can provide would be super helpful.

In addition, I am looking to build a solution that would allow me to repair IMeI and set TTL to 65 for all connected devices. If you can assist, I would be willing to pay for your time as well.

What do you mean with "repair IMEI"?
The IMEI is the serial number of the modem and reported to the cellular operator.

I'm not sure what repair means, are you asking if you can spoof/change an imei number to allow access to a carriers' network that only allows hardware that they've approved? If it's that then no, the mc7455 can be loaded with different firmwares and configs that are approved by different carriers, (US carriers mostly I think).
I use a modified openwrt called ROOTer and it uses this script to modify the TTL,


log() {
	logger -t "TTL Hack" "$@"

sleep 5
ENB=$(uci get ttl.ttl.enabled)

exst=$(cat /etc/firewall.user | grep "#startTTL")
if [ ! -z "$exst" ]; then
	cp -f /etc/firewall.user /etc/firewall.user.bk
	sed /"#startTTL"/,/"#endTTL"/d /etc/firewall.user.bk > /etc/firewall.user
	rm -f /etc/firewall.user.bk
if [ $ENB -eq 1 ]; then
	VALUE=$(uci get ttl.ttl.value)
	if [ -z $VALUE ]; then
	echo "#startTTL" >> /etc/firewall.user
	if [ $VALUE = 0 ]; then
		echo "iptables -t mangle -I POSTROUTING -o wwan0 -j TTL --ttl-inc 1" >> /etc/firewall.user
		echo "iptables -t mangle -I PREROUTING -i wwan0 -j TTL --ttl-inc 1" >> /etc/firewall.user
		echo "iptables -t mangle -I POSTROUTING -o wwan0 -j TTL --ttl-set $VALUE" >> /etc/firewall.user
		echo "iptables -t mangle -I PREROUTING -i wwan0 -j TTL --ttl-set $VALUE" >> /etc/firewall.user
	echo "#endTTL" >> /etc/firewall.user
if [ $FLG -eq 1 ]; then
	/etc/init.d/firewall restart

Not sure if the script will work as is but the iptables commands should work, albeit not persistent.

Yes, it is possible but this have nothing to do with OpenWrt.
Changing IMEI is illegal in some countries.