RUTX-50 SIM Failover

[sparkplug]

Hi,

I am completely new to Teltonika and have just received my RUTX-50.

At first I thought the second SIM port was faulty because nothing happened when I inserted a SIM, but I have learned that I could set it as the default port and then it worked correctly. I reset this back to having port 1 as the default.

I then tried to set up failover so that if I removed the card from port 1 it would failover to port 2 but this didn’t work.

I also have a Netgear Nighthawk M1 which I set into bridge mode and attached this via ethernet to the RUTX50’s WAN port and set up a failover rule with the same parameters which I had tried for SIM to SIM failover, and it worked perfectly.

So what am I doing wrong? There doesn’t seem to be a useful guide for this.

Here are the settings I have for the failover (wan is disabled in case it was interfering but if I turn it on then it works if I remove the SIM from Slot 1)

I also set up SIM switching with the default settings and added the “no network” and “on data connection fail” parameters.

I don’t understand why this doesn’t work?

[Daumantas]

Hello,

Since RUTX50 only contains one LTE/5G modem, Failover feature can only be used between wired WAN and the mobile connection, so since you also have a wired connection present, all 3 interfaces should be enabled.
SIM Switch seems to be configured correctly - after 3 failed checks with 30 second interval (3 x 30 = 90s) the router will switch to the second SIM, perhaps you did not wait long enough? Additionally, make sure to specify a rule when the RUTX50 should switch back to the primary SIM in the SIM2 tab.
Finally, make sure that the latest firmware version is used, as the previous versions contained issues with SIM Switch on RUTX50.

Best regards,

[sparkplug]

Thanks for the reply Daumantas,

The wired lan was just an experiment but it is no longer connected. I disabled the rule to make sure it wasn’t interfering with SIM to SIM failover.

Further testing today has revealed the problem.

In order to create a ‘data connection fail’, I removed the SIM card from slot 1. However, it seems that the RUTX50 doesn’t recognise this as a “data connection fail” in the way I interpreted the wording.

I guess it is probably specifically checking if the installed SIM is no longer connected to a network, but if a SIM is not installed then it can’t check that and just does nothing.

Interestingly, when I re-insert the SIM it does not get recognised unless I reboot the device. This is very frustrating.

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I did a second test by applying a data limit on SIM1 and it failed over to SIM2 correctly. After the timeout it reconnected to SIM1 and then failed back over to SIM2 as the data limit on SIM1 had not been cleared.

Working as expected!

@Teltonika - this is very clumsy. Perhaps you could add it as a bug report? Maybe add 'SIM removed" as an option in Failover if you need to keep it separate from “data connection fail” - but you should definitely have the router be able to identify that a SIM has been re-inserted into the slot and pick it up automatically.

Personally, I think the device would be much more useful with two modems to allow both SIMs to be combined to give better speeds / reliability. I know that would mean extra cost, but it would be worth it to me.

[Daumantas]

Hello,

@sparkplug

I guess it is probably specifically checking if the installed SIM is no longer connected to a network, but if a SIM is not installed then it can’t check that and just does nothing.

I’ve checked the behavior with “On data connection fail” by checking LCP echo, and after the SIM was removed and the specified time period has passed, the device successfully switched to SIM2. Are you sure you let the 90 seconds pass? You can check which SIM is currently active in the Status → Network → Mobile page or by the LEDs on the device.
If wired WAN will not be used, I’d recommend disabling the failover completely, as it’s not doing much in this configuration and could interfere with other services.

Best regards,

[sparkplug]

I realised that I’d updated the firmware on the router when I first installed it, but I had not done so for the modem.

I updated that before today’s tests.

To prevent waiting too long I set the delay to 5 seconds and 1 attempt on both SIM1 and SIM2

Failover set as before

On my first test I removed the card and it took 35 seconds for the 3/4/5G lights to start blinking on the front of the unit.

I waited 4 minutes from the removal of the SIM with no change and then re-inserted the SIM.

Two minutes later there was still no change so I rebooted the router from the web interface.

I really think this is bad. The router should be able to find the SIM again after it has been re-inserted without needing a reboot.

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For test 2 I decided to put the timeout intervals back to 30 seconds with 3 tries to see if that made any difference.

It took 15 seconds after I removed the SIM for the SIM1 light to go out on the front of the unit and 24 seconds before the 3/4/5G lights to start blinking.

Failover to SIM2 eventually worked, but it was 3 minutes and 20 seconds from initial removal of the SIM.

Also, until the failover actually worked, the overview reported that no SIM card was inserted in slot 2 (it was)

Once failover to SIM2 had worked I put SIM1 back in and waited for the 5 minute ‘switch back to default SIM’. This took about 30 seconds to work, but it did switch back OK.

So it’s a bit clumsy, and the times you put into the settings don’t seem to work properly or be accurate, but it sort of does what I want - eventually.

Failover from SIM to SIM is a feature I want because this will be in a moving vehicle so the idea is to put SIMs in from two different providers so if I’m in an area where there is no coverage for one then the other should work.

I’m considering keeping my existing Nighthawk M1 for the second SIM and connecting it via cable to the RUTX-50 as my tests with the WAN failover were much quicker and it would also allow me to do load balancing.

A shame to need two different units to do that and a shame that SIM to SIM failover seems to be a bit buggy.

I will do some more testing with WAN to SIM failover and see if that will be a better option for me, but it means a second antenna etc which is not ideal and it’s more expense.

If only the RUTX-50 did this better…

[sparkplug]

As a new user I’m only allowed 2 pics per post!

Firmware details:

[Daumantas]

Some optimizations for SIM switch are planned for v7.5, however, it should be noted that 30 seconds is around the expected time for the SIM switch to occur. This is because of the previously mentioned limitation of the device only having one modem, as the modem needs to unregister from the existing operator, switch the SIM card contacts internally to SIM2, and then undergo the entire registration procedure.
RUTX12 with the two active modems overcomes this issue, as both modems can be used at the same time and failover can be used to switch between the SIMs.

Let me know if you still experience this strange behavior when the v7.5 comes out.

Best regards,

[sparkplug]

Thank you Daumantas - you have been very helpful.

30 seconds is fine, but it took nearly 3.5 minutes to successfully complete the failover which is twice as long as I would have expected from the settings.

I will test again when 7.5 comes out.