Question

Hello,

I live in France. For 3 years, i use a RUT240 router to get access to the www, by mobile connection (PPP protocol) and by a SIM card of the Sosh (Orange) French Internet Service Provider (ISP). French ISP assigns Private IP addresses to their users. No worry until recently.

Since 3 o'clock in the night of the first of February 2023, RUT240 can't get access to the www anymore.

So, i tested with an other ISP operator (RED SFR SIM card), but it doesn't help.

Then, i updated the firmware to RUT2XX_R_00.01.14.6 version, but it doesn't help.

Then i updated the firmware again to RUT2_R_00.07.03.3 version. On the firmware Teltonika Wiki web page, i read that PPP protocol for mobile connection has been deprecated. So, i supposed that updating the firmware would solve my problem. But it doesn't help.

Then, i had reset RUT240 to default factory settings. But it doesn't help.

Then, i tested a lot (almost all) of various settings in :
* "System - Setup Wizard" panel,
* "Network - Mobile - General" and "Network Operators" panels,
* and "Interfaces - General - Network interfaces" panel, "MOB1S1A1" interface.
But it doesn't help.

Among my tests, i did a manual operator scan in "Network - Mobile - Network Operators - Operator scan settings" panel. Sosh Orange (ISP) SIM card inserted, information coming from the scan are :
* "Status = Available ; Operator Name = Orange F ; Short Name = Orange ; Numeric Name = 20801 ; Network Access Type = 4G",
* "Status = Forbidden ; Operator Name = 'Free' or 'F SFR' or 'F-Bouygues Telecom' ; Short Name = 'Free' or 'SFR' or 'BYTEL' ; Numeric Name = '20815' or '20810' or '20820' ; Network Access Type = 4G".

Relevant information coming from "Status - Network - Mobile" panel are :
* "SIM card state = inserted and ready",
* "Operator = Searching or N/A",
* "Operator State = Not registered",
* "Cell ID = N/A",
* "Data connection state = Disconnected",
* "Connection type = No service or 4G LTE",
* "Carrier aggregation = Single",
* "Connection band = N/A or LTE B20" .

From "Administration - Troubleshoot" panel, frequently relevant (i'm not an expert) information coming from "System log" file are :
[...] "daemon.err mobifd: [gsm.modem0] Failed to get nat mode"
[...] "daemon.err mobifd: [gsm.modem0] Failed to parse current VoLTE state"
[...] "daemon.info mobifd: [gsm.modem0] APN 'websfr' or ('orange.fr') isn't prepared for PDP 1, preparing it"
[...] "daemon.info mobifd: [gsm.modem0] APN 'websfr' or ('orange.fr') was successfully prepared for PDP 1"
[...] "daemon.info mobifd: [gsm.modem0] Attempting to establish connection to operator with 5 (then 10, 15, 30, 60, 300) seconds of timeout"
[...] "daemon.info mobifd: [gsm.modem0] Trying to connect to "20810" operator" ("Operator scan settings" - "Connection mode" on "manual")
[...] "daemon.err mobifd: [gsm.modem0] Failed connect to "20810" operator" ("Operator scan settings" - "Connection mode" on "manual") .

Entire "Troubleshoot" file is attached.

In conclusion, i don't know how to solve my problem.
Because i don't have a permanent second means to access the www, i can't look for information to solve my problem only by myself.
Could you help me please ?
Thanks for your support.

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Answer 1

Hello,

  

Thank you for such a detailed write-up!

The best course of action now would be to perform a factory reset using the bootloader method. Install RUT2_R_00.07.03.4 firmware version. The Bootloader method cleans the device completely, thus any issues from upgrading the firmware should be resolved.

Please keep in mind, that PPP is an old technology that is not supported by most carriers now. Thus I suspect that this is the reason it stopped working for you. The date would also make sense.

If the previously described step does not help, I'll ask you to replicate the issue, navigate to System → Administration → Troubleshoot and generate a troubleshoot file. It can be attached to the original post and will only be visible to Teltonika moderators.

  

Best regards,
DaumantasG

Comments

Hello DaumantasG,

I. First period of non-functional mobile connection

* Without performing further firmware updating, reset to default factory setting, "network – mobile" and "mob1s1a1 interface" settings test, than those already performed before my first post (the 15 th of February),

* and without performing a factory reset using the bootloader method (in reference to your first answer of the 17 th of February),

* then since the 18 th of February, mobile connection of RUT240 to ISP's networks became functional again (4G and the www were reachable).

So, my scenario would be that :

* the first of February, the ISPs definitely disabled PPP mobile connection protocol, on their networks,

* the 6 th of February, despite i updated the firmware to its last version (00.07.03.3), mobile connection of RUT240 to ISP's networks was not functional until the 18 th of February,

* so, showing that ISP's didn't enable, on their networks, at least an other mobile connection protocol, leading to a service discontinuity.

I complained about it to ISP’s, but they told me nothing about the technical aspects of my issue.

Q1 : What would be your explanation ?

II. Second period of non-functional mobile connection

For some days just before the 8 th of March, while i was browsing the www with my computer, RUT240 rebooted by itself several times. I don't understand why, no reboot setting was enabled. So, before i shut down or reboot RUT240, i will get into the habit of downloading the troubleshoot files.

For the day of the 8 th of March, there has been an increasing number of unsuccessful mobile connection attempts of RUT240 to ISP's networks, and then until now RUT240 was and is unable to establish at least one successful connection.

Troubleshoot files are attached to my first post (there are a lot of openvpn logs, which could be erased in order to read files in a more comfortable way). I only tested ipv4/6 setting.

Therefore, one troubleshoot file created the 12 th of March, without openvpn instance, is also attached.

Q2 : How could you explain that, since the 8 th of March until now, mobile connection of RUT240 to ISP's networks was not functional, again (second period) ?

Q3 : Was the 00.07.03.3 version of the firmware already outdated ?

III. A way towards a solution

Wanting to catch up on my backlog of work, i didn’t reply to your first answer (of the 17 th of February). Nevertheless, i worked on how to do a factory reset using the bootloader method.

The screen print attached shows the way that my bootloader WebUI looks like. This is the old bootloader version which only supports legacy firmware version.

So, i have to previously upgrade my bootloader to its new version, and then i could install the firmware in its last version. From the crowd-support forum, my understanding is that Teltonika website don’t allow the downloading of bootloaders.

Q4 : How can i get the last new version of the bootloader ?

Thanks for your support.

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Hello,

  

It seems like all of the issues can be explained by one signal parameter - RSRP. In all of your troubleshoot files, the signal parameters seem quite poor, but RSRP is very weak in particular. From most of the TS files, the parameters look like so:

• RSSI: -85 dBm
• RSRP: -120 dBm
• SINR: 4.8 dB
• RSRQ: -14 dB

And all of these values are present on B20 of the LTE spectrum, which operates in quite low frequencies. This means that even when you get a connection, the speeds will most likely be very bad. Signal strength recommendations can be found here.

Now regarding the question of why it sometimes works and sometimes doesn't, this could be related to many reasons, however, the main factors that could be causing the disconnections are:

• Worsening weather conditions;
• Increased tower load;
• Carrier could be using some power-saving technology and reducing the signal strength;

In this scenario things can be tried:

• Make sure both of these antennas are screwed in properly and are oriented vertically;
• Place the router in a much more open area with a clearer sight of the cell tower;
• Invest in a directional antenna. Information regarding third-party antennas can be found here.

Signal strength can be checked by navigating to Status → Network → Mobile. In the latest firmware (v7.4.1), the signal strength according to the recommendations will also be displayed:

 

Let me know if any of the steps above help!

  

Best regards,
DaumantasG

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Hello DaumantasG,

So, the issue is mainly not about PPP mobile connection protocol, which has been probably disabled by ISPs. Regardless of this, i updated RUT240 firmware to its 07.04.1 version.

In 2020 and 2021, i downloaded trouble_backup files, but i can’t find signal parameters in theses files. Others troubleshoot files are attached to my original post.
Just below, from the gsm.log file, i gathered signal parameters, sorted out by periods.

0. Before the first of February 2023
No information

I. Since the first to the 18th of February 2023, first period of non-functional mobile connection;
the 06th, 08th and 11th, AT MY HOUSE :
RSSI - Received Signal Strength Indicator = -78 to -83 dBm (Fair)
RSRP - Reference Signal Received Power = -112 dBm (No signal)
RSRQ - Reference Signal Received Quality = -9 to -11 dB (Good to Excellent)
SINR - Signal to Interference plus Noise Ratio = 8 to 6 dB (Fair to poor)

II. Since the 19th of February to the 08th of March 2023, period of functional mobile connection;
the 19th, AT MY HOUSE :
RSSI = -78 dBm (Fair)
RSRP = -115 dBm (No signal)
RSRQ = -11 dB (Good)
SINR = 3 to 0 dB (poor to No signal)

III. Since the 08th of March 2023 until now, 2nd period of non-functional mobile connection;
the 08th and 12th, AT MY HOUSE :
RSSI = -79 to -88 dBm (Fair to Poor)
RSRP = -111 to -120 dBm (No signal)
RSRQ = -11 to -14 dB (Good)
SINR = 9 to 0 dB (Fair to No signal)

About all of theses values and periods, i would say that :
* it's a shame that i don't have any signal parameters, before the first period of non-functional mobile connection (the first of February 2023), to make a comparison. Indeed, it would have probably showed an attenuation of all signal parameters;
* however, between the first period of non-functional mobile connection, and its second period, the lowest values of RSSI, RSRP and RSRQ signal parameters decreased by 5 dBm/dB. So, the issue has worsened a little;
* i agree with you that actual RSRP values (-111 to -120 dBm) are below the -100 dBm level allowing a connection. That's why i am surprised that, for the period of functional mobile connection (since the 19th of February to the 08th of March, - 115 dBm), i got a functional connection with good speeds (no black/white answer ?; How could you explain it ?);
* i would add to your analysis that actual SINR values (9 to 0 dB), are just above the disconnection level (0 dB) and only allow a poor connection;
* i would add to your analysis that actual RSSI values (-79 to -88 dBm) and RSRQ (-11 to -14 dB), allow a “fair to poor” and a good connection respectively;
* so, i would conclude that, both RSRP (received power from the cellular tower) and SINR (signal to interference ratio) values have to be substantially increased, at least by +30 dBm and +13 dB respectively;

About factors of disconnections, i would say that :
* my house is in the countryside, there are not a lot of people around the tower, so i would exclude the cellular tower load factor;
* for 3 weeks mobile connection is non-functional, so the weather conditions factor can be excluded;
* i don’t know how to analyse the competing signals factor;
* according to your advice, the 30th of March i went to the town hall, which is nearer to the cellular tower and with a clearer sight on it. Some of my private local characteristics are attached to my original post.

the 30th, AT MY HOUSE, about 495 meters away from the cellular tower, and at an altitude of 950 meters :
RSSI =  -84 dBm (Fair)
RSRP = -117 dBm (No signal)
RSRQ = -13 dB (Good)
SINR =  3 to 1 dB (Fair to poor)

the 30th, AT THE TOWN HALL, about 350 meters away from the cellular tower, and at an altitude of 960 meters :
RSSI = -81 dBm (Fair)
RSRP = -107 dBm (No signal)
RSRQ = -9 dB (Excellent)
SINR = 8 to 6 dB (Fair to poor)

The cellular tower is at an altitude of 1075 meters.

By comparison with values got at my house, RSRP value increased by about 10 dBm but still don't allow a connection, and SINR value increased by about 5 dB but still only allow a poor connection.
As you can see on the map, there is no nearer location to the cellular tower, in order to get signal parameters.
However, i could get signal parameters from a location which is at about the same altitude than the cellular tower (if people accept to supply power to RUT240). I question whether this test is necessary.

* i have used RUT240 for more than 2 years, in the same location (my house) and in a same environment (in my house; as far as i know, the environment around my house hasn’t been modified). For 2 years, i never got such a long period of non-functional mobile connection (very rarely non-functional).
Although there are physical barriers between RUT240 and the cellular tower (a little hill whose altitude profile is showed on the map, and obviously a few walls of my house), as far as i know they haven’t been modified, so i would exclude the physical barriers factor;
* as you can see on the map, my house is not far from the cellular tower (about 495 meters away), so i would exclude the proximity to the cellular tower factor. That’s why i am surprised that i got too weak RSRP values;
* my house is 125 meters below the altitude level of the cellular tower. I don’t know how to analyse this parameter.
What could be your analysis about the proximity (and altitude profile) to the cellular tower factor ?

* as you told me about it, carrier could be using some power-saving technology and reducing the signal power. As far as i know, and due to insufficient production means of electricity in France for the end of 2022 and until now, industries and privates have reduced electricity consumption.
With the help of consumer protection organizations, i will investigate whether ISPs carriers are affected by electricity saving policy or not. I will complain again about my problem to ISPs carriers and to relevant authorities.
So, ISPs carriers reducing the signal power could explain that, since the first of February 2023 RSRP can't allow any connection, and that consequently SINR only allow a poor connection (interference levels remaining the same).

* all people just around me access the www with smartphones. They don’t have any problem. How could you explain it ?
Is a smartphone able to “automatically” increase by itself the received power from the cellular tower ? Is RUT240 able to do it also ?

According to your advice to invest in a directional antenna :
i read information regarding third-party antennas.
* Concerning the polarization parameter of RUT240 mobile antennas, i don't have any data about it. So, i didn't know if antennas are vertically polarized or cross polarized. And, could you tell me what cross polarization implies ?
However, i got RUT240 turn around, and at each 45 degree angle, i have read signal parameters, to find out whether RUT240 antennas are polarized in a specific direction or not, by matching cellular tower broadcasting and receiving antennas polarization of RUT240, and consequently to get the best values of signal parameters. The result is that signal parameters are the same and don't vary in function of antenna positioning. So, RUT240 antennas are omnidirectional.
* Concerning antenna gain parameter, in order to provide the best coverage i understood that i have to choose an antenna with the appropriate gain, according to the distance to the cellular tower (5 dBi for devices in close range, and 7 or 9 dBi for distant devices).
I frequently move house in France, so these distance will be variable. Then, how to choose the gain antenna ?
A solution would be to be able to set the gain on a same antenna. Is an antenna with an adjustable gain available for purchase ?
An other solution would be to buy an omnidirectional antenna with a high gain. Is it possible ?

* Concerning antenna directivity parameter, i understood that you advise me to buy a directional antenna of this type "Directional antenna (18dBi)".

* Could the antenna reduce interference ?

So, by taking into account all previous data and constraints :
what models of antenna could you advise me to buy ? Could you please to have my problem and the solution checked by an Teltonika antenna expert ?

Thanks for your support.

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Hello,

  

Once again, I would like to thank you for providing a lot of useful information!

Now to the issue - As I do not live in a mountainous area, I'm not sure how the operators deal with the directionality of their antennas in such situations, so I cannot really comment on whether your altitude in relation to the cell tower could affect the readings that much. This all depends on how the carrier has oriented its antennas. However, as I understand you live in a population center, thus it would not make much sense not to cover your area. Thus I believe we can confidently roll out any actual coverage issues.

I've checked the location on Google Maps, and as I understand, there is a hill between you and the cell site, is that correct? That could interfere with the signal a little, but it does not explain why the signal would deteriorate over time.

The idea of a hardware failure should also not be thrown out of the window, however, I personally have not heard anything about devices losing the signal over time as a symptom.

Now about the antennas. You are correct - the RUT240 original antennas are omnidirectional and are meant to operate in a wide range of environments. The choice of directional antenna is in your hands, however, I would recommend using an antenna with less gain than 18dBi, as this antenna would be very directional, and could negatively impact the performance. Remember - more gain does not mean a better antenna. In your case, a 5-8 dBi antenna should work just fine, as you are very close to the cell tower. I have linked to this article in my last message, but just as a reminder, third-party antenna recommendations can be found here.

Regarding polarization - most LTE antennas are cross-polarized, this is just the way cell tower antennas transmit and is not affected by the device itself.

While we have not done many tests with third-party antennas, I would recommend considering our partner Poynting. For example, XPOL-2 or XPOL-16 would be great in your setup, as they are:

• Uni-directional;
• Water-resistant;
• Support wide range of frequency bands;

Let me know if you decide to go with an external antenna and inform us of the results!

   

Best regards,
DaumantasG