Quectel EP06-A in LHG R won't connect. I have put together 3 other LHG R routers with the same radio (EP06-A), same router OS version (7.2.3) and the others have worked (although not always without tinkering around). The same SIM works in another hardware model and it is activated on the same AT&T plan as our other LHGR & EP06-A devices that are working.

Router OS versions tried: 7.3.1, 7.2.3
Modem firmware: EP06ALAR02A08M4G_01.003.01.003
Carrier: AT&T

Sample of recent logs:
14:08:48 lte,async,raw lte1: rcvd
14:08:48 lte,async,raw lte1: sent AT+CSQ
14:08:48 lte,async,raw lte1: rcvd +CSQ: 29,99
14:08:51 lte,async,raw lte1: sent AT+QENG="servingcell"
14:08:51 lte,async,raw lte1: rcvd +QENG: "servingcell","LIMSRV","LTE","FDD",311,580,2E6D506,221,2425,5,2,2,12,-74,-9,-51,25,-
14:08:51 lte,async,raw lte1: sent AT+QCAINFO
14:08:51 lte,async,raw lte1: rcvd
14:08:51 lte,async,raw lte1: sent AT+CSQ
14:08:51 lte,async,raw lte1: rcvd +CSQ: 31,99
14:08:53 system,info,account user admin logged in via local
14:08:54 lte,async,raw lte1: sent AT+QENG="servingcell"
14:08:54 lte,async,raw lte1: rcvd +QENG: "servingcell","LIMSRV","LTE","FDD",311,580,2E6D506,221,2425,5,2,2,12,-74,-7,-53,22,49
14:08:54 lte,async,raw lte1: sent AT+QCAINFO
14:08:54 lte,async,raw lte1: rcvd
14:08:54 lte,async,raw lte1: sent AT+CSQ
14:08:54 lte,async,raw lte1: rcvd +CSQ: 31,99

Modem is set to MBIM using this command:
AT+QCFG="usbnet",2

Router 'modem' setting on LTE interface tab has been set to "auto" and "mbim" without success.

LTE interface settings:
/interface lte apn
add apn=broadband ip-type=ipv4
/interface lte
set [ find ] allow-roaming=yes apn-profiles=broadband band="" name=lte1

Modem info is detected on the lte interface:

/interface/lte mon lte1
status: searching
model: EP06-A
revision: EP06ALAR02A08M4G
imei: 869258***
imsi: 310280***
uicc: 8901280***

I have tried temporarily changing the EP06-A setting to usbnet,1 as this fixed another setup of the same hardware. When I change using the command, AT+QCFG="usbnet",1, then check the modem status with the command, AT+QCFG="usbnet", it still shows it is using AT+QCFG="usbnet",2.

Any ideas on how to fix?

thank you.

FYI in case anyone else runs into the same problem. Mikrotik support reviewed the supout file and determined:

Well, you can monitor the interface to see if the modem is stuck on 'searching' and you can read through the log file, in the previous supout there was this:
Jul/06/2022 07:41:13 lte,debug lte1 mbim: >>> E service: conn_ext, command: lte attach config, error: INVALID_PARAMETERS
Which suggests that there was something wrong about the configuration used to attach to the network.{}

After contacting Mikrotik support, I went to Quectel forum to ask this question. Now, the issue seems to have randomly gone away after time (see article below for details).

Quectel forum post:
https://forums.quectel.com/t/ep06-a-wil ... at-t/15640

It seems Mikrotik router OS was not setting the APN properly. The issue was resolved by sending the AT command below directly to the modem (even though the APN is properly configured in RouterOS APN config).

/interface lte at-chat lte1 input="AT+CGDCONT=1,\"IPV4V6\",\"broadband\""

Mikrotik, I believe this is a bug.

On all new LHG R radios with any new EP06-A, I have to run the same command or it will not work (we have continued to deploy these configurations and I have had to do this on about 5 or 6 in a row or they won't connect).

Thanks for this. This helped me get EP06 working on IPV4 on UK network EE, which until I ran this command would only connect IPV6 which isnt terribly useful.

Interestingly I had to use that EXACT command. If I tied it with the networks APN “everywhere" it made no difference. I can now enjoy the benefits of EP06!

Kudos.