Hello MikroTik ninjas!

Would really appreciate help troubleshooting this LTE issue preventing me from using MikroTik for uplinks. Long-time MikroTik implementer here, but first time deploying an LTE modem from MikroTik.

I am not getting any LTE connectivity, even though I tested the SIM with a phone and had excellent reception at the site.

This is what I do, then see, with both the RBSXTR&R11E-LTE6 and ATLGM&EG18-EA so far:

1. Put in SIM
2. Power via PoE
3. Face toward Tower ( out a window at first, while configuring )
4. Open up winbox and login with credentials on the device
5. Accept the auto-configuration
6. Add APN information and apply to LTE interface
7. Hard reset just to be sure the modem reinitializes
8. Watch the status and activity on the LTE interface

When I do that, I just get a searching status with I use /interface/lte/monitor lte1 which periodically hits deregistered then tries again after an interval.

There is no log activity with any errors that I see. It just appears as if it cannot find a tower at all. But I am in a pretty good spot, relative to the tower, and I verified reception with a phone, fwiw.

There is no running status on the interface, and it has no activity.

This has happened with both the devices I listed above.

Any clues on what might be happening here?

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Looking further, it seems the ATL and SXT might both be missing B13 and B66 which the towers I plan to use these with favor. Back to the drawing board? Looking through MikroTik products, there does not seem to be one available for bands 13 and 66.

Anyone have success with bands 13 & 66 with MikroTik? Seems the Chateau alone supports those, but it is a full-fledged switch & router, and interior mounted. Just looking for a modem, with gigabit PoE, and ideally exterior mounted.

Mikrotik hates North America for LTE. B13 suggest you have Verizon, which is particular unfriendly to Mikrotik (or any non-Verizon certified device). Only the one Chateau for US should work, but I haven't tried that.

The ATL be worthless in a lot of places(/most/all?) in US. It does not support B13 or B66 (nor B2 or B12), return it be my recommendation.

Assuming you're in the US... my recommendation be to use an AT&T SIM (or some MVNO that use them) if you want like the SXT. It does well at "mid-band" (~1900Mhz), which AT&T has tons of spectrum in that range. It even supports some CA modes with on LTE6 with AT&T. T-Mobile might also work, but they have more low-band frequency on average (B12), which the SXT antenna isn't well suited for, but check you area if you want to use T-Mobile. You can use something like https://cellmapper.net to see, at least some, of the cell towers in your area.

Thanks a lot @Amm0 -- pardon my delay in replying.

I came to your same conclusion about MikroTik LTE products in the Northwest hemisphere.

Basically any band I would want, few if any support.

I ended up going with another brand for the modem aspect so far, but deeply miss RouterOS and the specificity of control we have with that.

Seems like the only way to get LTE support that actually works in the Northwest hemisphere is to get an "R" device ( without modem ) and then hand-pick from the compatibility list.

Yeah I add modems modules to the wAPacR's. We've been using the Telit LM960's and then wire up the 4 MIMO SMAs to bottom of wAPacR to use a proper antenna.
That works well... although, not a huge fan of us having to put together the parts – I'd actually rather buy a unit with a Cat18+ "global" modem.
The other units like LtAP ("full size" and mini) could do same - but there not ARM so you don't get the full RouterOS feature set (e.g. ZeroTier, which is extremely useful with CGNAT-based LTE).

The Chateau LTE6-US does actually support decent bands (e.g. covering AT&T and Verizon), although the CA abilities are limited. The issue with Chateau is AFAIK is NOT certified by Verizon, so you can active a new Verizon SIM on them, since the IMEI is not "whitelisted" from certification – you can swap SIM from a some other Verizon-compatible device but a PITA. AT&T doesn't not have these restrictions.

Great recommendation, thanks a lot @Amm0

Is this in the supported range for that product model in your implementation? https://techship.com/products/telit-lm9 ... 08T0WA000/

Any tip on a good supplier of those? Both for the wAP and the modem? I am also in the Western US.

Seems like the overall package is twice the cost of the ATL! But that modem looks like a beast. And I am very glad to know you have it working with the wAP R AC!

Yeah I get them techship and that's the one there. Only downside is they are expensive, but it 4x4 MIMO & the wAPacR only have one SIM slot. Mikrotik even added support to read the CA data and RSRQ/P/etc at some point, so it gets full LTE signal information & it's on their list of "Support Peripherals". Still use some Sierra modems, but all the newer high-category modems are M.2 & Mikrotik only shows RSSI with Sierra modems.

You do need to buy at least 4 x MHF4 to SMA pigtails, since these use small connectors than the more typical U.FL. And only thing to configure them is using /system/serial-terminal to access the modem, and then issuing "AT#USBCFG=2" to get the modem into MBIM mode. It should select the right carrier settings based on the SIM card, but possible AT#FIRMWARE=? may be needed.

BUT they are NOT whitelisted with Verizon, so they won't activate them using the IMEI from the Telit modems (or any modem not in a certified device). It's annoying since the LM960s modems are actually certified by Verizon, but Verizon require the device there in to be certified. AT&T and T-Mobile don't care since modem is certified.

And other downside there is no FOTA or firmware upgrade support, so to upgrade them... you have to take the modem out and flash on desktop/laptop with USB-to-miniPCIe adapter.

But yeah the wAPacR with Telit LM960s have worked well for us.

What a tight-packed intel drop there @Amm0 -- "legendary" level of specificity, thanks so much for the details. That's a copy & paste of insight avoiding years of trial and error.

Standing back, it sure seems like there is not just a lot of cost, but a lot of margin for error, and not a lot of comfortable feelings if I were deploying 100 of these per quarter.

You gestured to this agreeing not having pre-built devices is not-ideal at all... but zooming out even further, I feel like MikroTik has no answer for this device, for example ( understanding that is not outdoor )

https://www.cudy.com/productinfo/1007065.html ( Cudy; 4G LTE Cat. 18 AX1800 Wi-Fi 6 Router, Model: LT18 )

That is built on the Quectel EG18: https://www.mouser.com/datasheet/2/1052 ... 009883.pdf

But it also feels like we live in the blind-spot of the entire global LTE-A situation. Super weird situation compared to pulling an ATL off the shelf and calling it done, versus... this.

For today, thank you so much out there. What a ninja to have arrived at the arrangement you have. So grateful for all the hard-won data here.

OH MAN! It's so close! Upon closer inspection... That's honestly a difference of the EG18-EA versus the EG18-NA being used in the ATL!!!

Cosmic facepalm

It seems like I have overlap on 2, 12, and 17 with this prebuilt wAP based on the R11e-LTE: https://mikrotik.com/product/wap_ac_lte6_kit

Going to give that a try to buy us like 9-18 months to plead for for someone to pop an EG18-NA into the ATL.

If you're willing to give up on Verizon, the wAPac-LTE6 works pretty well with AT&T. Same with SXT-LTE6 actually. Both will do a 2+12 carrier aggregation with AT&T which should be on most towers. You just the loose ability to use additional bandwidth from Band 66, which is widely available on all carriers in US. And since AT&T does have a lot of 1900Mhz spectrum, that's more in the sweet spot of the SXT's antenna, so might want to consider that. Not to be an ad for AT&T, but at this point, that's the safest/easiest path to decent LTE in US from Mikrotik. Upload be way higher on SXT-LTE6 than wAP-LTE6 assuming it was pointed & has two SIM slots. Conversely SXT downside is it's MIPSBE so no ZeroTier, and 100Mb ethernet. While wAP is 1Gb ethernet.

Verizon is where there are 0 good options, other than BYO-modem. Specifically it's the lack of Band 13 (which is a case of well-intentioned FCC rules gone very wrong). I think if you use an already activated Verizon SIM it will LTE6 may work since the do have some band 2 and 12, depending on location – just Band 13 and 66 are there prevalent bands so seems like a bad plan. Even the US Chateau isn't certified for Band 13, so it needs same SIM switching to work with Verizon.

Not as familiar with T-Mobile, but they are more of hodgepodge of bands depending on location. AFAIK they use a lot of low-band LTE in rural areas, but the SXT's antenna isn't well tuned for low-band - why avoided them & two cell carrier was enough to deal with.

Same with SXT-LTE6 actually. Both will do a 2+12 carrier aggregation with AT&T which should be on most towers.

Right there was where my heart sank. I started with the SXT-LTE6. I basically just purchased another device made with the exact same modem. I feel like I have a core fault in my thinking somewhere.

The ATL ( with EG18-EA versus -NA ) was an outright mistake to purchase at all, but the SXT must have had an error in provisioning, or had an infrastructure access problem. Possibly in "Assuming it was pointed" but possibly not. Toward the end you talk about antenna, so maybe that part being different has a chance. But now I am expecting to run into the same problem and be back at square one.

When I started with the SXT, it would never switch to running in status, and would only power on, switch to searching on the lte1 interface, fail fail fail, change to deregistered and sit fussy in the diaper for a bit, then switch back to searching ... and loop like that. I ran scans, and saw everything but AT&T around here, but the carriers available would fluctuate and eventually show none or very few.

Starting to wonder if there was something I could have done with the SXT, but it got ruled out for me on 10/100M on the remote chance I could get over 100M down, and on the chance I needed one or both ethernet ports for actual LAN transfers. I don't need/want WiFi so it feels like the wAP is mostly a waste, but maybe I can find a use for the extra muscle versus the SXT. If it works at all.

Alright, so. Regrouping now that I found the actual wall with my face. A lot of great buzzwords to search there though, especially ZeroTier. The history of bands you mentioned was illuminating, especially when looking at urban cellular grids. The reason for this or that band in a region is starting to make sense. Especially in the context of the original subject of this now-shifted thread.

Definitely using AT&T, and plan to keep it that way: there is a tower 1 mile away from one test site, right on top of another. Verizon has one closer, but my strategic partner ( multi-carrier reseller ) does not have unlimited plans through anyone but AT&T.

Hoping the last sentence holds the key:

AFAIK they use a lot of low-band LTE in rural areas, but the SXT's antenna isn't well tuned for low-band - why avoided them & two cell carrier was enough to deal with.

Do you mind expanding on what you mean by "low-band"? Are you talking about the integer number of band identifiers being low, or something that might explain what I described with the "searching" behavior?

The bands get confusing. By "Low Band" I mean sub 1000Mhz generally... And T-Mobile uses Band 71, which is particular low in the 600Mhz range. AT&T and T-Mobile use Band 12 are around 700Mhz. Band 13 and 17 are different parts of Band 12, so also low band...and FirstNet/AT&T uses Band 14, also in same range. The SXT in particular is not tuned for any of these (and doesn't even support all of them). NOW "low band" should work — just a different antenna design be more ideal.

BUT... if AT&T... SXT-LTE6 should do AT&T Band 2 pretty well. Band 2 is around 1900Mhz, which I call "Mid Band", and the SXT directional antenna SHOULD be pretty good at that. But maybe there isn't Band 2 in your area. The LTE6 should be able to combine it with Band 12 using "carrier aggregation" – even antenna isn't ideal, it still get some bandwidth from that.

Anyway that SXT-LTE6 should actually work with AT&T.

On the "searching", did you uncheck "Use Network APN" in the "LTE APNs" dialog from Interface > LTE. Otherwise it would take "broadband" or whatever APN you're using.

"Use Network APN" means use value from SIM. So if you have some custom APN, it won't authorize.

What a journey so far. Thank you so much for jumping in beside me in this one @Amm0. I have a solid link now, outperforming my local WISP at the harder of the two test locations. I am testing both rural and urban, and had been thrust into this by needing to assure better-than-Starlink performance to high-profile clients, with sovereignty and resilience. Essentially online independence from the access side, like we do from the operations and cloud side.

From my title of the post, I can see now looking back, I did not know the actual problem. 13 & 66 being sought was definitely a carrier decision, and I was stumbling around in the device options available to suit my situation. I went through 4 devices total, and with the wAP AC LTE6, not only is the link established properly finally, it also hits a key requirement of shielding the structure from the signal. Without WiFi on, the LTE connection alone is directional. And it has a metal plate behind it. In reading the RF pollution, it made a huge difference and was not expected. It also carried a signal no problem through some obstruction, without a serious mast.

From the beginning I had "Use Network APN" turned off, but that last piece unraveled the last step to get the LTE6 to work. Not enabling or disabling it, but not seeing the option at all, then realizing the device needed to be fast-forwarded to the newest ARM release of RouterOS. After that was done, the "Use Network APN" option was visible, the modem firmware upgrade was shown, and the connection overall came up. The first time I saw it live was at the modem firmware update download.

Not sure what happened with the SXT-LTE6 kit that I started with, which apparently ought to have worked. But I had two of those, overconfident in the first round of devices, and neither did. I updated the OS in that case also though, so it was "ghosts" then, apparently. Either way I am a lot happier with the wAP AC LTE6 on the metal back, 1000M ethernet, serious CPU and RAM difference, etc, etc. Technically, this could be the only device I deploy in some locations, other than maybe a switch.

Like I started with though... what a journey. I really appreciate nuanced breakdowns of concepts in and around the target so I could wake up to the fact I was stumbling around the problem. As you talked it became clear I had no idea what was actually at play, none of the domain common sense, and was actually artificially alone, because serious ninjas have been in this section for a long time. The relationship I formed with MikroTik and the community by being pissed for the first time ever, might actually pay off +10X because rather than connect a modem to a tower, this all connected Me.

Time to move on to multi-WAN!

I followed this thread from the beginning out of curiosity.
Nice feedback, I am sure this may help quite some others stumbling on similar problems (like myself).

And yeah, props to Amm0

Been at this before Mikrotik sold routers with LTE modems. Used to use RB953s with two Sierra MC7354 modems – all still alive and working after 5-10 years.

But wAPac are likely best choice today. Only downside is no PoE passthough like SXT & limited flash memory. But the wAPac are ARM (so they run ZeroTier). And you can get with the LTE6 modem, or the "R" version with just modem slot to add a modem, or add external antenna with pigtails. All same hardware is nice property.

But this boiled down to the two most LTE problems:
1. ALL software/firmware not at latest or mismatched – THREE possible things need to be updated for LTE (see below)
2. Some issue with APNs – all requiring understanding the "Use Network APN" setting

The US specific lesson is Verizon is not good choice with Mikrotik. Possible, but highly problematic. So clue here was Band 13 is ONLY Verizon in US. And the ATL...I knew wasn't that was very unlikely to work in North America with ANY carrier.

Update everything is kinda tricky if you don't know all the places things live. So here is quick "cheatsheet" since this isn't the first time I've answered an LTE question, to find the mis-matched verisons was likely the cause. Now Mikrotik is kinda bad at shipping seemingly random version/firmware on devices — so always updating everything when you get one is important IMO...

I think these are the basic commands to setup a new wAPac or similar (outside of ANY networking/routing stuff):

Super grateful again for the epic LTE thread here @Amm0

Have since mounted the wAP ac LTE6 outside, powered over PoE, outperforming the local WISP, load-balancing two uplinks. PCC multi-WAN is going well... when applicable, see below.

About to roll this into a reproducible configuration, and have the second wAP ac LTE6 ready to be provisioned!

Starting to run into issues more having to do with load-balancing and will thread off on that, but otherwise, have been loving the wAP ac LTE6! Awesome to have a provisioning script like that for reference, and extremely helpful to get a real sense of what matters most in these configurations.

Going to seriously test the resilience though! I mounted it inside a plastic telco box just so it was not in direct sunlight.

Main head-scratchers right now, which I will likely open new threads on in the appropriate place:

Cannot reach winbox through intermediary router:
- I have the wAP bridged to ether1 off of lte1, via the APN settings, so ether1 is the WAN IP.
- When I was directly connected to the LTE6 without a router, I could access winbox via MAC address.
- Now that there is a hEX between my workstations and the uplinks, I cannot hit the MAC address of the LTE6.

Cannot load-balance VPN connections, and leaking IP:
- I know this is likely not related to either uplink at all, but I am seeing bad load-balancing distribution.
- Each device individually connects to a VPN, so it seems like in the PCC modality, load-balancing will pin to one connection or another.
- Then the load of WAN traffic disproportionately hits one connection, so it is pretty much behaving as fault-tolerance and not load-balancing right now.
- Figured I would need to connect to the VPN at the router ( and/or at the LTE modem on that side! ) then load-balance over two VPN connections; one per uplink.
- Then no longer use client-side VPN connections, and hopefully it will then spread the load better, as well as be more performant.

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As usual there are head scratchers, but it has been 100% worth it to stick with MikroTik. I would be dying a thousand deaths right now trying to deal with some random GUI or super locked down device with one option available to tweak from among thousands being suppressed, ever to be tuned.

Was able to figure out the first gotcha: "Cannot reach winbox through intermediary router"

And noted that here: viewtopic.php?p=1037126#p1037126

RoMON to the rescue.
- https://help.mikrotik.com/docs/display/ROS/RoMON
- https://www.youtube.com/watch?v=Peg6UcSJ_eA

Moving on to the next gotchas!