Quectel EP06 - 2 routers ONE with "No Service" / "MM_MODEM_DISABLED""

Installing and Using OpenWrt
1

I have installed the same firmware on both routers.
Zbtlink ZBT-WG3526

https://firmware-selector.openwrt.org/?version=24.10.1&target=ramips%2Fmt7621&id=zbtlink_zbt-wg3526-16m

For configuration I use luci-proto-modemmanager and modemmanager.
To analyze the root cause of the problem, I go to the console.

I use the following AT commands to check both routers.

get modem - same on both routers

echo 'ATI' | socat - /dev/ttyUSB2,crnl

Quectel
EP06
Revision: EP06ELAR04A04M4G

get band settings - same on both routers

echo 'AT+QCFG="BAND"' | socat - /dev/ttyUSB2,crnl

+QCFG: "band",0x8d0,0x1a0880800d5,0x0

get network information

echo 'AT+QNWINFO' | socat - /dev/ttyUSB2,crnl

#1: +QNWINFO: "FDD LTE","26203","LTE BAND 3",1600
#2: +QNWINFO: No Service

Signal quality

echo 'AT+CSQ' | socat - /dev/ttyUSB2,crnl

#1: +CSQ: 31,99
#2: +CSQ: 99,99

Both routers stand next to me in the same room.
All SIM-cards working only in the router #1 without any problems.

Please do not hesitate to correct me

INFO:
With modemmanager I solve the connection problems after hours with 23.05.5 / 24.10.0 / 24.10.1 on router #1. That's why I bought the same router again.

2

Get rid of ModemManager completely, switch the modem to MBIM and follow https://openwrt.org/docs/guide-user/network/wan/wwan/ltedongle

3

Okay, back from ModemManager to MBIM with these steps

check the modem mode before set

echo -e 'AT+QCFG="usbnet",2' | socat - /dev/ttyUSB2,crnl

set the mode of the modem to MBIM

echo -e 'AT+QCFG="usbnet"' | socat - /dev/ttyUSB2,crnl

reset the modem

echo -e 'AT+CFUN=1,1' | socat - /dev/ttyUSB2,crnl

configure the APN outside luci

echo -e 'AT+CGDCONT=1,"IP","internet"' | socat - /dev/ttyUSB2,crnl

set scan mode to 'auto'

echo -e 'AT+QCFG="nwscanmode",0' | socat - /dev/ttyUSB2,crnl

I will inform you, if the re connection problem during one day will return or not.

Kind regards @AndrewZ for your solution. Internet is working over LTE

4

Reconnection issues are common, search the forum for "watchcat" related posts.

5

Not the right answer - MM uses MBIM and QMI - QMI is a service within MBIM...

Anyways - get all the dependencies, and you might have to configure the modem directly - so I'd suggest installing pioocom and use it there...