Issues with EM12G and EM7455 on Calyx

[hw1353]

I have a few family and friends I've deployed LTE internet setups for, almost all of them are using Calyx.

I've been setting up these calyx devices for a bit, and have some questions I'm hoping someone can provide a bit of insight on.

For older Calyx plans, with the sprint branded sim cards, do these require occasional OTA updates to remain functional? I have a calyx account I payed for last year that I use for testing purposes before I order calyx for a customer. I have a customer switching from Visible to Calyx, and have been letting them use my calyx sim as a test drive for a few days.

Both the Sierra EM7455 and EM12g have frequent disconnects on the service. I've tried magic on both modems, testing to see if its related to IMEI mismatch of the hotspot originally provided by calyx.

I've tried locking bands, and also tried a EM12G modem in place of the EM7455, and also switched the router from a WE826-T2 to a NEX6GO model. Disconnects keep happening.

I'm using The Wireless Haven Active PoE equipment, 36w injector.

When I arrive after they have told me its 'down', I don't see anything out of the ordinary in the debug window. Nothing reports limited service, however, the internet is not accessible. Modem and router appear fine. Just seems that the LTE data has been shut off. (Somewhat seems after the connection is idle for awhile, this happens)

Tower is 2 miles away from this residence. I've tested the tower up close, pushes Band 2,4,12 and 66 (2 and 12 seem to provide the fastest speeds, band 4 on this tower is extremely slow). I've tried locking out all the bands other than 2 or 12. Still seems to shut off the LTE data 2-3 hours after a reboot.

I didnt grab a snip of the GSTATUS settings, but SINR is 9-10, RSRP is less than 100 typically, ECIO is 7-8, RSSI is 65-75. Signal quality and speeds are great when tested across several devices, even my test MR1100.

Tested in both WE826 & Nex6GO inside an enclosure mounted on the roof, with CISCO-4G TNC antennas. Powered by POE.

EM7455
-Generic Firmware ~ 2019
-IMEI updates
- r.ispsn APN IPV6

EM12G
-Generic MDM profile
-IMEI Updates
-Autselect disabled
- r.ispsn APN IPV6


I have several Calyx customers using EM06 and EM12g modems, that can stay powered on for 2-3 months and never need a reboot. The hardware is essentially the same across these deployments, most is sourced from thewirelesshaven.com

Unfortunately, these people are 30 miles away, and driving there and back takes near a hour. Quick fixes aren't that quick.

1. With Calyx sprint plans, do you have to re-insert the SIM into the original hotspot periodically for OTA updates? - Either way, the sim works well in MR1100 and any of my other rigs. Other customers have been working for months without needing the original hotspot. So I'm not sold on this conclusion.

2. Something else I'm noticing, is I can commit several config changes to the EM7455 (selrat=06, band locking, etc,) and then when I return a day later, everything has been reverted to default (selrat=01, bands=01/all cell/lte bands, etc), is it possible for the tower to reset the settings on this modem? What can I do to prevent that? ( I originally thought this to be the issue of the disconnects, settings get reset, connects to band 4 - which allows you to connect, but no LTE data on that band)

3. On the EM12g, I can commit the changes, and save them with QPRTPARA=1, and they persist, but I still get disconnected randomly, same as with the EM7455. (About every 2-3 hours)

What else can I do to try and locate/understand this issue(apart from living at their house for a day?) Is there some verbose logging I can turn on and syslog somewhere?

Hate to let customers go, but driving an hour 3-4 days in a row after work sucks(I do this on the side, apart from my day job). Hoping someone can point me in the next steps for troubleshooting.

Thanks! and sorry for the long post!

[MattB29]

Could be a tower based issue. Can you test the setup in a different tower zone to see if the disconnects still happen?

[hw1353]

Could be a tower based issue. Can you test the setup in a different tower zone to see if the disconnects still happen?

I've considered the same thing, my only issue with that, is at home, if the local tower goes down for a bit, and then comes back up, I don't need to reset anything. The LTE data comes back on its own. I have ATT and verizon plans I use at home.

Another thought along those lines, is when I show up to troubleshoot the issue, the modem is still connected to the tower on the correct bands, and simply resetting the modem/router resolves the issue - reconnects on the same bands. Resetting the router/modem every 2-3 hours just isn't feasible.

Another problem with performing that test, is the modem will work flawlessly while I'm there. I've load tested the setup for over an hour multiple times. Multiple streams running, downloading apps, browsing the web, all simultaneously. I dont have the time to wait for a few hours for the disconnect to happen. So if I wanted to test this setup from another tower, It'd have to be there for a few hours. I do not have any other friends and family in the area where I could leave a rig to test a different tower

Unfortunately, theres no sprint or t-mobile service where I reside, only faint ATT and verizon. So testing at home is not an option.

I may let things sit a few days and see if the tower issues work out on their own. Could be bad timing on my part(maybe tmobile is working on the tower? idk)

[MattB29]

Possibly a long shot but have you tried switching out the Sim during your troubleshooting search?

[Didneywhorl]

Make sure you have "Drop Invalid Packets" enabled under Network->Firewall.

Maybe play with the MTU setting at that location as well

[hw1353]

Possibly a long shot but have you tried switching out the Sim during your troubleshooting search?

Switching out the SIM? At the moment I only have one Calyx SIM card, as I only have one account I use to test with, or I use it on the road.

Make sure you have "Drop Invalid Packets" enabled under Network->Firewall.

Maybe play with the MTU setting at that location as well

I'll double check the MTU and the drop invalid packets setting, thanks Didney.

Any suggestions on the EM7455 dropping its settings every 24 hours? Is there a trick to make settings stick like with the quectel modems? (IE saving the current config with QPRTPARA=1?)

[Didneywhorl]

That I've not seen myself, the settings reversion. Might be a NVRAM problem? I don't think the Sierras act like the Quectels when it comes to that, I've never heard of a command like the =1 that matches Sierras RMARESET command, though I've never queried it via AT!RMARESET=?

Careful with that command though, you may end up in the ass pain low power mode.

[hw1353]

That I've not seen myself, the settings reversion. Might be a NVRAM problem? I don't think the Sierras act like the Quectels when it comes to that, I've never heard of a command like the =1 that matches Sierras RMARESET command, though I've never queried it via AT!RMARESET=?

Careful with that command though, you may end up in the ass pain low power mode.

I’ve seen it with a mc7455 I have as well, will drop everything back to stock settings.

I may try doing a double reflash of the firmware on the em7455.

It’s annoying because of the loss of the band locking, and it removes the LTE only data(selrat=06) back to default as well. Somewhat frustrating from a troubleshooting perspective.

One other question with usb composition, is there a preferred composition carrier to carrier? IE is it better to run MBIM with Verizon and QMI with calyx/att?

[Didneywhorl]

For Sprint, and now most carriers, when using Rooter based firmware (WiFiX is) I prefer MBIM as it seems the support for MBIM works a little better.

My opinion.

check your debug log and watch it as it scrolls by for a while, it doesn't save to a file, and see if the router is sending commands that are clearing your settings. It is very possible. Also, check to see if your imei OPENLOCK is locked back up so that it cannot be changed without re-unlocking via the openlock key process. If the modem has been factory reset this will be unlocked. Some people will factory reset the modem to bypass having to unlock it to get to the imei commands. This is not teh best way and can leave the modem open for changes by means other than your manual command sending.