Several questions about Omnia - mostly about LTE modules and Omnia UI in comparison to MOFI 4500

I’ve been looking for a decent OpenWRT-based LTE router and saw an Amazon ad for Turris Omnia. It looks very promising though it doesn’t include an LTE module. I figured I have to obtain my own - and make sure it’s actually supported in Omnia (availability of kernel modules, firmware etc).

  1. What is the best 4G LTE module currently available that’s supported in Omnia and widely available for purchase?

  2. I currently use MOFI 4500 and it has Sierra MC7455. Is it supported in Omnia? Do I need any extra hardware to mount it? Its pins look different to what’s in Omnia, it doesn’t appear to be mini-PCIE.

  3. Does Omnia come with a friendly UI for configuring failover / dynamic routing? In MOFI 4500, the UI is okay, and it uses mwan3 to change routing dynamically. module is the Sierra LTE interface, and apcli0 is a Wi-Fi connection to my Wi-Fi hotspot which doesn’t have a way to be USB-tethered. Screenshot:

  4. In general, is Omnia a good replacement for MOFI 4500? MOFI looks to be EOL plus it’s causing me trouble. It randomly slows down or refuses to assign DHCP to new clients, and only a restart helps. It’s very annoying. Please note I don’t really care about Omnia’s NAS features - I’m only interested in its networking and routing features.

  5. Is there a UI that can help me route certain traffic via VPN? AT&T throttles data transfer to YouTube servers, plus my video in Google Meet/Hangouts is potato. When I connect to VPN, the problem goes away. But I don’t want to route everything through the VPN.

  6. More of an OpenWRT question than Omnia question but here it is: is there an QoS/SQM algorithm that is LTE-friendly? What I mean by that is my speed varies, it can be 25mbit now, and 10mbit 10 seconds later. Setting my download speed to a certain value doesn’t make sense. If I set it to 25mbit and my network is capable of doing 50mbit at this moment, I’ll artificially limit myself to 25mbit. And when the available bandwidth goes down to 10mbit, QoS simply doesn’t work because it thinks it has enough bandwidth to make everyone happy (which it does not).

Thanks in advance for your answers.

I’ve been using an MC7455 in my Turris Omnia for a few years now. It’s not straightforward, because the MC7455 uses MBIM and there is no native support for it in the Turris OS. I had to search a bunch of places to find a compatible protocol module for luci to get it working. I had it working on Turris 3.x and Turris 4.0, but I’ve just now upgraded to Turris 5.0 and it is once again not working. Hopefully I’ll be able to sort out the problem soon.

Also, I originally bought my Omnia router with the LTE kit, which included a slower modem at the time, and a large chunk of metal heatsink to attach on top of it. That of course worked out of the box, but … silly me, I hadn’t installed the heatsink properly, and the modem eventually baked itself to death after a couple of years. If you install the MC7455 in an Omnia, you will also need a large heatsink for it, one tall enough to touch the top of the router case, so it can sink heat to the case. I had to buy a couple of thermal pads to add on top of the chunky heatsink to make it have good contact with the case. Again, if you don’t do this, the modem will overheat over time.

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Fyi, I’ve gotten my MC7455 working with Turris OS 5.0 now. I’ve submitted the necessary changes back to OpenWRT:


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In past, once when there was Turris Omnia campaign on Indiegogo, we were selling Quectel EC20 as part of LTE pack, but once time goes, it was superseded by Quectel EC25.
And on support, if I remember correctly, there were users, who were using Sierra Wireless MC7455 and Sierra EM7565. For example, you can check this: https://www.lteforum.at/mobilfunk/turris-omnia-lte-router-project.6379/

There’s a list of supported LTE miniPCIe cards in Turris routers, which was done by our community.
https://wiki.turris.cz/doc/en/public/lte-cards

It depends on what is a friendly UI for you. In the web interface re/Foris, which we developed, there is no such option yet. In the advanced administration LuCI, there is a tab for that and options can be seen for example here:

And in LuCI, you can configure certain traffic via VPN.

Sure with failover/load-balanding (mwan3) this is possible.
https://openwrt.org/docs/guide-user/network/wan/multiwan/mwan3
And also, there is a SQM, which can help you with LTE connection only.
https://openwrt.org/docs/guide-user/network/traffic-shaping/sqm

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Unfortunately no. The issue is that LTE modems (like most other devices with the exception of a few ethernet drivers in Linux) give no feed back about the amount of buffered data internal to driver and LTE chip. sqm however needs this information to decide when to hand the next packet(s) to the driver/device. Forsome devices like ethernet, DSL, DOCSIS we can assume a more or less fixed transmission rate and can set an artificial transmission rate inside the linux qdisc layer which allows SQM to work. But variable rate devices like LTE or wifi really need to to some of the work themselves, see for example the airtime fairness patches in ath9K and ath10K. If your LTE link is relative stable, you can instantiate SQM with a fixed rate, below your expected minimum LTE rate, which will allow SQM to do its “magic” albeit probably for a relative large sacrifice in peak rate.
Hope that helps…

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@hyc Awesome. The fact you just got it working today is reassuring. And these contributions to the upstream, great! Thanks for that. Hope they get merged soon.

@hyc @Pepe How do you connect Sierra MC7455 to Omnia? From what I understand, Omnia has a Mini PCIE connection while MC7455 is a USB device. https://wiki.turris.cz/doc/en/public/lte-cards says “There needs to be isolated USB pins3 to avoid pin incompability” but I don’t understand this language (clarification needed), plus even if isolate the pin, how do I connect USB to PCIE?

@Pepe @moeller0 Thanks for your answers. I guess I’ll buy it and try it. Having a modern OpenWRT platform with beefy hardware underneath sounds like a great idea. I was also considering Peplink but OpenWRT is more convincing to me.

@Nowaker the MC7455 comes as a mini-PCIe card. The mini-PCIe spec also supports USB on the same card interface.
https://source.sierrawireless.com/devices/mc-series/mc7455/#sthash.2TPGDy2J.dpbs

You have to tape over some pins, as described in the link that @Pepe posted. That’s the same link that I followed to get my modem to be recognized. Just cut a small piece of Scotch tape (or equivalent), put it over the pins, then plug it into the slot.

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@hyc Thanks for explaining. “There needs to be isolated USB pins3 to avoid pin incompability” is still very cryptic to me. Could you clarify which pin numbers exactly should be taped?

Thanks a lot!

See the images in this post https://www.lteforum.at/mobilfunk/turris-omnia-lte-router-project.6379/seite-8.html#post-108560

Note that you can also safely cover the intervening ground pins, so it’s easier to just cut 2 pieces of tape like this https://www.lteforum.at/mobilfunk/turris-omnia-lte-router-project.6379/post-108573

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Awesome @hyc, thanks! My Turris Omnia is on its way!

Enjoy. Let us know how everything goes.

BTW, why do we even have to cover these pins? Is there a bug in OpenWRT, or Omnia changes to OpenWRT?

@hyc Speaking of cooling down the Sierra module, is there any off-the-shelf hardware you used to do that? Links to Amazon or other sources would be most helpful! Thank you in advance.

As I mentioned, I bought the original LTE option with mine, so I have the original heatsink. It’s basically a large chunk of aluminum with some adhesive thermal pads on top and bottom. I don’t know where you can buy those but I imagine any machine shop could slice one up for you. See https://www.youtube.com/watch?v=hCRCpw7a-P8

You can buy the thermal pads from Amazon, sure. Just search for “thermal pad” and you’ll get plenty of choices.

About cooling heatsink, don’t hesitate and give it try to ask our sales department (sales@turris.cz). I am sure they will figure out something for you :wink:

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Thanks! Just them an email.

czc.cz

No shipping to the United States available. :frowning:

Try Discomp instead.

https://www.discomp.cz/turris-omnia-chladic-pro-lte-modem_d97680.html

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Shipping turned out to be like $40 and it would take a while to arrive. I’m researching alternative solutions.

Do you guys know if Omnia has any fan connectors? The information is pretty scarce. Something from 2016 where @Pepe appears to say PWM is supported, someone else saying it’s not. By looking at my Omnia, I’m not seeing any PWM connectors. There’s 4 pins in bottom left, but as per this image, it’s GND, UART0_TxD, UART0_RxD, +3V3. Not PWM 12V.