Diagnose Dropped Internet MOFI 4500 from Syslog?

[BuzzardFromMars]

My internet drops several times a day on my MOFI 4500 (SIM7 COMBO) where the internet light turns off and then within a minute or so it reconnects automatically and everything is fine.

This is NOT the same issue as the hot topic [SOLVED!] Losing constant Internet connection on Mofi 4500 (and my mind).

I am able to grab the system log around the time when this happens and wonder how to determine if this is something caused by my router or just simply a temporary bad signal, etc. Any pointers as to what to look for would be appreciated.

[gscheb]

Hello,
Might want to start by posting your signal strength stats.

[BuzzardFromMars]

Good point. I assumed since I am getting good speeds I was ok but after posting these numbers, I see that some are considered in the range where I may get drop outs, correct?

CSQ: 25
Signal Strength: 80%
RSSI: -63 dBm
ECIO: -12 (RSRQ) dB
RSRP: -90 (RSRP) dBm

[Dr-BroadBand]

What are your Speeds?
What Network are you on?
Have your tried to band lock onto a band?

[BuzzardFromMars]

I am locked on to Band 14 and get speeds of around 25 down / up, ping ~30ms on AT&T network.
Tower is 4.1 miles away.

[gscheb]

Good point. I assumed since I am getting good speeds I was ok but after posting these numbers, I see that some are considered in the range where I may get drop outs, correct?

CSQ: 25
Signal Strength: 80%
RSSI: -63 dBm
ECIO: -12 (RSRQ) dB
RSRP: -90 (RSRP) dBm

According to this don't look bad to me.

Signal Metrics.PNG

How long have you had this Mofi?

[BuzzardFromMars]

Interesting, I found a similar chart but with ranges showing me more in the fair range. I've had this MOFI for only about 4 months.

[Dr-BroadBand]

Your number look very nice!!
Band-14 is FirstNet. Are you a first responder??

[Dr-BroadBand]

Wait your EC/lo is in the Poor range if the chart above is correct.

[Dr-BroadBand]

EC/IO

The EC/IO is a measure of the quality/cleanliness of the signal from the tower to the modem and indicates the signal-to noise ratio (the ratio of the received/good energy to the interference/bad energy). It is measured in decibels (dB). In a perfect world, where there is no true interference, the interference level is equal to the noise level resulting in an EC/IO = 0 dB. Once the EC/IO is above ~ -7.0 dB, your connection is going to suffer.

There are several factors that can contribute to a higher EC/IO value, including florescent lighting, electric motors, equipment, power supplies, bad/poor cabling, trees, hills, buildings, walls, shorted connectors, inaccurate antenna alignment, wrong antenna polarization, congestion at the tower, etc.

[Dr-BroadBand]

Clean Power, MoFi Road Trip.

Would bring your MoFi to the cell tower for some testing, to get a baseline.
Then add distance, cables, Connectors, antennas ...Blah...Blah.
Take good notes and share with the group

Little things like what day & time of day could be good clues!!

https://www.amazon.com/gp/product/B06ZY ... UTF8&psc=1

[Actinidia_arguta]

Hey guys,

I figured I would piggy back on this post, seeing as I'm having the same issue as OP with the same hardware (MoFi 4500 SIM7). My connection repeatedly drops and reconnects, and every time the internet LED indicator goes out for a minute or two and then comes back on.

I noticed when this happens, I see an error message under the "Signal/Cell Information" page of the router administration UI --

Code: Select all

SIM IMSI: SerialOpenErr2[/dev/ttyUSB2

The "SIM ICCID:" field will then show blank, and "Registered on Network:" changes to "NO". After a minute or so it will reconnect and all of the fields will fill out with their respective numbers, etc. This happens randomly but often, sometimes only a few minutes between drop outs. While the modem is disconnected an error message also appears on the "Mofi Network Module Updater" page --

Code: Select all

Module Firmware: MOFISIMSerialOpenErr 2 [/dev/ttyUSB2

Do you see these same error messages, BuzzardFromMars? This is happening on Bands 4, 13 & 66. I get a good signal on band 13, so I don't think it's that. I also reflashed the modem from 1.0.1-std to 1.0.2-std with no effect. I sent an email to MoFi a couple days ago and haven't heard anything back from them. I will attached the screen shots I sent them to this post as well. Screenshot (9).png shows the status when it's working properly, and the other 3 show the error messages.

Thanks for the help guys! Hopefully this is the same problem that OP is having, and we can get both our issues resolved!

[BuzzardFromMars]

This is great info, sounds like we are experiencing the same issue. I will try to capture the info from my end to compare. Thanks!

[Adm1jtg]

According to this don't look bad to me.
Signal Metrics.PNG
How long have you had this Mofi?

Ummm I think I remember that chart and the one you posted is for 3g not lte. The lte one is farther down the page.
Going fro memory but those numbers dont seem right. Signal quality is excellent below -10, good from -11 to -15 and -16 to -20 is poor. Gong from memory but pretty sure thats right

[Actinidia_arguta]

Oh, I also found the router becomes unresponsive for a moment when this happens when connected via wifi, or when using IP passthrough to my AmpliFi router. I'm looking back through all of the many screenshots I've taken, and it looks like I was wired directly into the MoFi ethernet port every time I was able to see the error messages. Otherwise the webUI became unresponsive.
We'll get this!

[Actinidia_arguta]

I just tried to use the WebShell and I keep getting an error message:

Code: Select all

/usr/lib/lua/luci/dispatcher.lua:448: Failed to execute cbi dispatcher target for entry '/quick/system/WebShell'.
The called action terminated with an exception:
/usr/lib/lua/luci/cbi.lua:334: Unable to read UCI data: shellinabox
stack traceback:
	[C]: in function 'assert'
	/usr/lib/lua/luci/dispatcher.lua:448: in function 'dispatch'
	/usr/lib/lua/luci/dispatcher.lua:195: in function </usr/lib/lua/luci/dispatcher.lua:194>

I also tried to PuTTY into the router. The SSH connection keeps timing out before I'm able to do much. The idea was to see if I could issue a few simple AT commands, to gather some more data. Hrmmm.

[BuzzardFromMars]

I'm getting these messages when I drop:

Thu Oct 11 15:22:01 2020 user.notice iface-monitor:: / Action: ifdown / Interface: module
Thu Oct 11 15:22:01 2020 daemon.notice netifd: module_dhcp (25045): udhcpc: received SIGTERM
Thu Oct 11 15:22:01 2020 daemon.info sim7[8978]: stopping SIM7 connection mgr daemon
Thu Oct 11 15:22:01 2020 daemon.notice netifd: Interface 'module_dhcp' is now down
Thu Oct 11 15:22:01 2020 daemon.notice netifd: Interface 'module_dhcp' is disabled
Thu Oct 11 15:22:01 2020 daemon.notice netifd: Interface 'module_dhcp' has link connectivity loss

I think some of my signal values are just in the range where drops are to be expected.

[Actinidia_arguta]

Well, at least that's a potentially fixable problem with a new antenna. I assume you are using the stock flappy paddle antennas? Pretty sure those are only 3 dBi gain, so there is definitely room for improvement. Unfortunately it's the type of problem you have to throw money at in order to solve it. Unless you want to build a Moxon antenna or something.

I'm pretty sure I have a hardware issue causing my problems, and MoFi support still hasn't responded to my email from last Wednesday. I've already ordered a Quectel EM12-G with router and such to replace it. I'm going to try to return the MoFi, assuming I can get in touch with them lol.

One thing I would like to know is, which directory is the syslog located in, and what's the best was to pull it? I meant to poke around with PuTTY to find it, but that would require being able to mantain an SSH connection for more than 10 seconds, so....

Hope you get your internet woes figured out, my friend!

[BuzzardFromMars]

Well, at least that's a potentially fixable problem with a new antenna. I assume you are using the stock flappy paddle antennas? Pretty sure those are only 3 dBi gain, so there is definitely room for improvement. Unfortunately it's the type of problem you have to throw money at in order to solve it. Unless you want to build a Moxon antenna or something.

I'm pretty sure I have a hardware issue causing my problems, and MoFi support still hasn't responded to my email from last Wednesday. I've already ordered a Quectel EM12-G with router and such to replace it. I'm going to try to return the MoFi, assuming I can get in touch with them lol.

I was never able to get a single reply from them to answer anything via email, I even submitted a ticket on their website. They do answer the phone though so I was able to get sales and talk to them.

One thing I would like to know is, which directory is the syslog located in, and what's the best was to pull it? I meant to poke around with PuTTY to find it, but that would require being able to mantain an SSH connection for more than 10 seconds, so....

I was never able to find the syslog by logging in via PuTTY. I looked EVERYWHERE. I even did a "grep" command to search all files for words I knew were in the log and I could never find the log so I just use the system log from the UI.

Hope you get your internet woes figured out, my friend!

Same to you!

[Mattflexreed]

-7 DB doesnt seem to cause my connection to suffer. I'm nearly at -10 and have good signal. Just lots of congestion

[wildcats1983]

I am having this same problem. I just got my Mofi4500 on Thursday. It worked decent that I noticed up til today.

Anyone find out whats going on and how to fix the problem.


My device specs..
Device: MOFI NETWORK MOFI4500-4GXeLTE-V2
Modem: SIM 7
Firmware Version: 4.3.1-std