GL-X750 LTE connection woes

Technical Support for Routers
1

Background information:
Router: GL-X750
Modem: EP06-E
OS: 3.028 and OpenWRT master r12194

Config:

config interface ‘wwan’
option proto ‘qmi’
option apn ‘internet’
option delegate ‘0’
option pdptype ‘ipv4’
option auth ‘none’
option device ‘/dev/cdc-wdm0’

Problem:
The LTE connection drops randomly. It can run up to 2 days or 6 minutes but it will drop randomly and doesn’t recover. Very annoying when you are trying to stream a movie. Normally a reboot solves it but sometimes the router needs to be rebooted 2-3 times before it will connect again. to 4G
Judging from the logs below it looks like it disconnects and then attempts to get a new ip address but that fails. Tried a couple of uqmi commands without avail and now running into a lack of knowledge about AT commands/minicom. Does anyone know what the trick is to get the modem to fetch a new ip address after the connection drops?

Kernel log:

[ 1228.218462] usb 1-1.2: USB disconnect, device number 4
[ 1228.224292] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
[ 1228.233020] option 1-1.2:1.0: device disconnected
[ 1228.238461] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1
[ 1228.247146] option 1-1.2:1.1: device disconnected
[ 1228.252543] option1 ttyUSB2: GSM modem (1-port) converter now disconnected from ttyUSB2
[ 1228.261226] option 1-1.2:1.2: device disconnected
[ 1228.266691] option1 ttyUSB3: GSM modem (1-port) converter now disconnected from ttyUSB3
[ 1228.275533] option 1-1.2:1.3: device disconnected
[ 1228.281166] qmi_wwan 1-1.2:1.4 wwan0: unregister ‘qmi_wwan’ usb-1b000000.usb-1.2, WWAN/QMI device
[ 1233.374476] usb 1-1.2: new high-speed USB device number 5 using ehci-platform
[ 1233.566654] option 1-1.2:1.0: GSM modem (1-port) converter detected
[ 1233.573616] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB0
[ 1233.581674] option 1-1.2:1.1: GSM modem (1-port) converter detected
[ 1233.588505] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB1
[ 1233.596802] option 1-1.2:1.2: GSM modem (1-port) converter detected
[ 1233.603812] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB2
[ 1233.611819] option 1-1.2:1.3: GSM modem (1-port) converter detected
[ 1233.618833] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB3
[ 1233.821431] qmi_wwan 1-1.2:1.4: cdc-wdm0: USB WDM device
[ 1233.837334] qmi_wwan 1-1.2:1.4 wwan0: register ‘qmi_wwan’ at usb-1b000000.usb-1.2, WWAN/QMI device, x:xx:xx:xx:xx:xx

System log:

Wed Feb 12 22:11:58 2020 kern.info kernel: [ 1228.218462] usb 1-1.2: USB disconnect, device number 4
Wed Feb 12 22:11:58 2020 kern.info kernel: [ 1228.224292] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0
Wed Feb 12 22:11:58 2020 kern.info kernel: [ 1228.233020] option 1-1.2:1.0: device disconnected
Wed Feb 12 22:11:58 2020 kern.info kernel: [ 1228.238461] option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1
Wed Feb 12 22:11:58 2020 kern.info kernel: [ 1228.247146] option 1-1.2:1.1: device disconnected
Wed Feb 12 22:11:58 2020 kern.info kernel: [ 1228.252543] option1 ttyUSB2: GSM modem (1-port) converter now disconnected from ttyUSB2
Wed Feb 12 22:11:58 2020 kern.info kernel: [ 1228.261226] option 1-1.2:1.2: device disconnected
Wed Feb 12 22:11:58 2020 kern.info kernel: [ 1228.266691] option1 ttyUSB3: GSM modem (1-port) converter now disconnected from ttyUSB3
Wed Feb 12 22:11:58 2020 kern.info kernel: [ 1228.275533] option 1-1.2:1.3: device disconnected
Wed Feb 12 22:11:58 2020 kern.info kernel: [ 1228.281166] qmi_wwan 1-1.2:1.4 wwan0: unregister ‘qmi_wwan’ usb-1b000000.usb-1.2, WWAN/QMI device
Wed Feb 12 22:11:58 2020 daemon.notice netifd: Network device ‘wwan0’ link is down
Wed Feb 12 22:11:58 2020 daemon.notice netifd: Network alias ‘wwan0’ link is down
Wed Feb 12 22:11:58 2020 daemon.notice netifd: Interface ‘wwan_4’ has link connectivity loss
Wed Feb 12 22:11:59 2020 daemon.notice netifd: wwan_4 (5526): udhcpc: sending renew to 100.109.91.228
Wed Feb 12 22:11:59 2020 daemon.notice netifd: wwan_4 (5526): udhcpc: connect: Network unreachable
Wed Feb 12 22:11:59 2020 daemon.notice netifd: wwan_4 (5526): udhcpc: sending renew to 0.0.0.0
Wed Feb 12 22:11:59 2020 daemon.notice netifd: wwan_4 (5526): udhcpc: sendto: Network is down
Wed Feb 12 22:11:59 2020 daemon.notice netifd: wwan_4 (5526): udhcpc: received SIGTERM
Wed Feb 12 22:11:59 2020 daemon.notice netifd: wwan_4 (5526): udhcpc: unicasting a release of 100.109.91.227 to 100.109.91.228
Wed Feb 12 22:11:59 2020 daemon.notice netifd: wwan_4 (5526): udhcpc: sending release
Wed Feb 12 22:11:59 2020 daemon.notice netifd: wwan_4 (5526): udhcpc: connect: Network unreachable
Wed Feb 12 22:11:59 2020 daemon.notice netifd: wwan_4 (5526): udhcpc: entering released state
Wed Feb 12 22:11:59 2020 daemon.notice netifd: wwan_4 (5526): Command failed: Permission denied
Wed Feb 12 22:11:59 2020 daemon.notice netifd: Interface ‘wwan_4’ is now down
Wed Feb 12 22:11:59 2020 daemon.notice netifd: Interface ‘wwan_4’ is disabled
Wed Feb 12 22:11:59 2020 daemon.warn dnsmasq[1]: no servers found in /tmp/resolv.conf.d/resolv.conf.auto, will retry
Wed Feb 12 22:12:04 2020 kern.info kernel: [ 1233.374476] usb 1-1.2: new high-speed USB device number 5 using ehci-platform
Wed Feb 12 22:12:04 2020 kern.info kernel: [ 1233.566654] option 1-1.2:1.0: GSM modem (1-port) converter detected
Wed Feb 12 22:12:04 2020 kern.info kernel: [ 1233.573616] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB0
Wed Feb 12 22:12:04 2020 kern.info kernel: [ 1233.581674] option 1-1.2:1.1: GSM modem (1-port) converter detected
Wed Feb 12 22:12:04 2020 kern.info kernel: [ 1233.588505] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB1
Wed Feb 12 22:12:04 2020 kern.info kernel: [ 1233.596802] option 1-1.2:1.2: GSM modem (1-port) converter detected
Wed Feb 12 22:12:04 2020 kern.info kernel: [ 1233.603812] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB2
Wed Feb 12 22:12:04 2020 kern.info kernel: [ 1233.611819] option 1-1.2:1.3: GSM modem (1-port) converter detected
Wed Feb 12 22:12:04 2020 kern.info kernel: [ 1233.618833] usb 1-1.2: GSM modem (1-port) converter now attached to ttyUSB3
Wed Feb 12 22:12:04 2020 kern.info kernel: [ 1233.821431] qmi_wwan 1-1.2:1.4: cdc-wdm0: USB WDM device
Wed Feb 12 22:12:04 2020 kern.info kernel: [ 1233.837334] qmi_wwan 1-1.2:1.4 wwan0: register ‘qmi_wwan’ at usb-1b000000.usb-1.2, WWAN/QMI device, xx:xx:xx:xx:xx:xx
Wed Feb 12 22:12:05 2020 daemon.notice netifd: wwan (7690): Stopping network wwan
Wed Feb 12 22:12:05 2020 daemon.notice netifd: wwan (7690): Command failed: Permission denied
Wed Feb 12 22:12:05 2020 daemon.notice netifd: Interface ‘wwan’ is now down
Wed Feb 12 22:12:13 2020 daemon.notice netifd: Interface ‘wwan’ is setting up now
Wed Feb 12 22:12:13 2020 daemon.notice netifd: wwan (8331): Waiting for SIM initialization

2

It looks like the power supply is low. I suggest you check the power adapter.

3

The power supply I amusing is the the one that came with the unit , an 18 Watt one. Shouldn’t that be enough?

4

Do you have any other USB devices attached to the X750 USB port?

1 Like
5

Nope, not using any USB devices with the unit so that is why I asked if the 18W power supply should be enough. If you need more info please ask!

I might have a power supply with more wattage to test but until Saturday I am not home to test

6

NEVER ‘trust’ what the power supply label says … PROVE it. Get an electronic load and stop guessing if it’s a voltage drop issue.

Search for electronic load or dc load. Something like
https://www.ebay.com/itm/30V-60W-Constant-Current-Electronic-Load-Discharge-Battery-Capacity-Test-DC-E0R3/401913408023?hash=item5d93e7ea17:g:osAAAOSwIw1cBdgf

or

I’ve seen soooo many power supplies fail with time and heat, and as many that don’t meet their specs out of the box.

If the label says 5v 1A, it should still be OVER 5v at 1a … not 4.9, etc.

Get a tool to tell you what’s going on and move on to your real project ;]

(disclaimer - I randomly searched and selected above links. I have purchased similar units and use them every day.)

1 Like
7

Ordered a 24W power supply (12V, 2A) and unfortunately the problem of the dropped LTE connection persists.
So if it’s not a power issue and also not a software issue, it might be a sim issue. To test this hypothesis I have ordered a new sim which will arrive in around 3 days.

1 Like
8

How is the signal over there? Does the device work in 4G mode?

1 Like
9

Running :

uqmi -d /dev/cdc-wdm0 -s --get-signal-info

Shows:

{“type”:“lte”,“rssi”:-69,“rsrq”:-16,“rsrp”:-101,“snr”:-26}

Which, if I understand the values correctly, should be fine

10

Have you tried the ‘testing’ firmware from the download site?
Click the link under Pre Release for your router -
https://docs.gl-inet.com/en/3/release_notes/

I’m having issues with static IP with Spitz MiFi and Amarok. They solved the Amarok problem with a new firmware which I’m hoping they implement shortly for the Spitz and MiFi.

1 Like
11

Thanks for the tip. Did test a custom build of OpenWRT master but did not try the testing firmware yet.
Flashed and testing :wink:

12

And after 8 minutes of testing the testing firmware I had a connection drop.
Messed around with different uqmi and AT commands but to no avail. Yesterday the router worked fine but as of today it won’t recognize the sim card being inserted anymore.
Does anyone have more ideas?

Is it possible to open the unit to have a look around?

13

You can use the "AT + CPIN? " command to check your SIM card. If the result returns error, your SIM card is not inserted properly.

14

I’m a little late to this party but I’ve had my share of SIM not recognized problems.

A clean sim is a happy sim … alcohol is best but don’t soak it.

A piece of scotch tape on the back of the sim card puts a little more pressure on the connectors.

I’m sure you’ve already used the Modem Reset link on the main GL page.

My sims are ‘tripple cut’ and the GL devices use the middle size. Sometimes the smaller cut offsets from its outer counterpart. Set the sim on the table and make sure it is completely flat.

15

off the wall … how much does a static ip cost with your provider? With mine it solves a multitude of problems for under $10 a month …

17

@Technicavolous
Off_the_wall