Routing 4G cellular data to a BSD network using bridge mode on the RUT-240:
The RUT-240 from Teltonika networks is a small and fairly inexpensive 4G router which is commonly used to provide internet connectivity for remote devices that are either in locations without regular fixed-line broadband, or where high availability is required. Think smart meters, monitoring systems, and so on.
In the case of high availability, the RUT-240 is connected in line with a conventional internet router, and it's own cellular connection is only used when a lack of connectivity is detected. Both of these configurations often involve the use of a special SIM card, to which the cellular operator has provisioned a static, public IP address, thus allowing inbound connections to the connected remote devices, (as well as access to the router itself for configuration and admin purposes).
[...T]oday we're going to use our RUT-240 for a completely different purpose. No special SIM required, and we're not going to be travelling out in to the wilds either. Just a regular pre-paid SIM, and the normal office surroundings.
Instead, we'll be exploring the use of this router as a backup connection for an existing OpenBSD-based router, or even - within limits - as a replacement for fixed line broadband. This latter option might make sense on a short term basis in a new office that hasn't been fully connected yet, or in a temporary office in an awkward location where DSL or fibre isn't available. Attending a conference, but all the decent hotels are fully booked? Stuck on a boat in dry dock? Not a problem!
Of course, for the main intended purpose, 100baseT isn't exactly a limitation here. Typical uses of the RUT-240 involve connecting it to an existing wired internet connection via the WAN socket and passing that through to another device connected to the LAN side, with the possibility of routing traffic via 4G LTE if the wired WAN connectivity fails. In these cases, even if the connection between the existing devices was syncing at 1000baseT, (or beyond), then unless our actual internet connection can provide bandwidth in excess of 100 mbit then we don't really lose anything in terms of raw speed. Technically, latency might be worse, but the difference will be so small as to be lost in the noise compared to the extra latency created by the packet processing of the RUT-240.
An interesting hardware project - anybody fancy trying it with Windows or Linux? [JR]
(Score: 3, Interesting) by gawdonblue on Tuesday April 11 2023, @09:03PM (4 children)
... that sends CPU usage way up.
(Score: 1, Touché) by Anonymous Coward on Wednesday April 12 2023, @12:03AM (1 child)
Considering there are no scripts, either the SVG or CSS engines of your browser suck (I checked the source and the SVGs embedded, they don't have anything that looks suspicious).
(Score: 2) by gawdonblue on Thursday April 13 2023, @07:38AM
Just Firefox 112 on Mint. Nothing too unusual.
(Score: 1) by Crystal on Friday April 14 2023, @11:35AM (1 child)
As somebody who actually works for Exotic Silicon, (the site that published the article), I can assure you that there is nothing 'nasty' on the page.
The high CPU usage you are seeing is due to a Mozilla bug, specifically #1821864 which you can cross-check and verify in their bugzilla database.
Specifically, we use SMIL animation in our favicon, and the library that they use to render it is not very efficient.
Since not many websites use SMIL animations, especially infinitely repeating ones, this is why you are not seeing it more often.
Sure, if you don't like animated favicons, that's a valid opinion, but the point is that if we didn't push the boundaries and do things that other websites don't do, we wouldn't be fully doing our job as a research organisation and these browser bugs might never be discovered.
Also, it's somewhat hurtful to us to have false claims of 'nasty' content on our website. We pride ourselves on not carrying advertising, and making the whole site viewable without javascript, in text browsers, etc. So please refrain from making such unfounded claims in the future.
Any questions, feel free to contact us.
(Score: 2) by gawdonblue on Saturday April 15 2023, @12:32PM
Apologies, I shouldn't have labeled it nasty. I should have phrased it something like that my browser was misbehaving on that website, but I couldn't work out what was going wrong.
I did try disabling scripts, but there weren't any. And turning off media files, but this also didn't make any difference.
It is interesting that Chromium-based browsers disable animated favicons and that Firefox is considering going down that path. I wonder what Safari does.
(Score: 2) by driverless on Wednesday April 12 2023, @02:15AM (1 child)
There's a million of these devices out there, I have a surplussed Robustel R2000 that I paid $30 for which does pretty much the same thing, with optional OpenVPN and other tunnel types. All of them are pretty much no-brainers to set up, drop in the SIM, point your router to it as the primary or, in my case, secondary after fibre, and that's it. You can also get them from a million vendors on Aliexpress for much less than the RUT-240 costs. Not really sure why it warrants a post here...
(Score: 1) by Crystal on Friday April 14 2023, @11:51AM
You're right that in principle these routers don't require much in the way of configuration - if you are only using them on a simple home or small office network with just a few attached devices.
What we describe in the article is somewhat different. Using the router in bridge mode, (which many of the alternatives 'from a million vendors' that you mention cannot do), allows a user with a moderately complex internal network to avoid double NAT, and conveniently do further internal routing using their existing setup rather than try to duplicate that configuration on the 4G router