Hacking the Actiontec 56k Modem/Gateway 233
william_lorenz writes "The Actiontec Dual 56k External Modem is an inexpensive device with a built-in 56k modem and two Ethernet ports that can be used as an Internet gateway of sorts. What's great about it is that it runs some form of uClinux, it's easily hackable, and Greg Boehnlein of the Linux Users Group of Cleveland and NOOSS fame recently contributed a detailed report on his findings! Pictures of the board are also available here, here, and here. Lots of specific details are included in Greg's article, and there's been some further discussions about this on the LUGC mailing lists."
Inexpensive? (Score:2, Informative)
Re:Let the comments begin! (Score:1, Informative)
10,000 at 2MB each - 20,000MB. What's a few GB between friends... per image
Curiously, the images of this little 56k modem wonder are just the kind of things you LOVE to avoid on a modem connection!
Re:56k gateways (Score:2, Informative)
You pay through the nose for a shitty service, and until they fix that, both in price and reliability, I'll stick to abusing my work bandwidth and stay with the trusty old agravatingly slow, but unlimited bandwidth, 56K dialup for home net access.
At least with a dialup deal [tpg.com.au], I can set up bulk downloads of whatever (no i'm not a p2p junkie) and leave the auto-redialer on to re-connect when i get disconnected. i'd rather that than have to pay A$80+ for a decent home broadband connection.
Re:Who says modem must be used outgoing ? (Score:5, Informative)
56k only works if the isp can tap into the digital phone exchange...
Jeroen
Re:xDSL (Score:2, Informative)
i dont know what exactly you mean by "tweak", but many people seem to like linksys, i used to use one myself until i went to a homegrown solution.
The only problem I found with the linksys came after quite a bit of usage, and quite a bit of firmware upgrades, it was the model befsr41, and after a time, if you sent so many packets down the line/sec(i dont even have approx #), it would basically die for a couple minutes before it would come back up. SPI would also not allow for port forwarding. It was however the best router I have worked with before.
I have also helped a couple friends setup some ranging from netgear to dlink to belkin to microsoft. There are a couple quirks with each, like the netgear mr314. If you want to run a server behind that, it doesn't alias the external ip to the lan ports, so basically say you want to ping your external ip,...well you can't.
The microsoft, dlink and belkin i didn't work with quite as much(as far as in depth tweaking), but i assume there are quirks with each of the systems. For the sake of not liking things to be broken as far as functionality, i would recommend a linksys.
Re:They say it's hackable (Score:5, Informative)
But in any case, *since* the regulation was put in place, this allowed the telcos to move to digital switching, since they could know the limit of the signals they'd have to digitize to support all legal users/devices on their circuits. You have to admit, it would've been hard for them to carry on any other way -- Imagine if they still had to support racks of relays just to ensure your attempt to run ethernet-over-phoneline would work. Now imagine if they had to try to support that for *long distance* calling...
Now, DSL is a little different. For one thing, it terminates at the telco's central office racks, or a 'remote terminal' (basically a central-office-in-a-box that connects back to the main office over fiber or some extreme-speed-over-copper solution), so the telco only has to support line quality over a limited, known distance. For another, it takes advantage of technological advancements to run up in relatively high, definitely inaudible frequencies*, so there's little risk of corruption to others' voice service... and further, the hardware is, in fact, advanced enough to pick from any of a number of 'channels,' such that, while it's still only a point-to-point tech, it can avoid crosstalk from your neighbor's link by running on completely different frequencies. Practically speaking, it *is* the best thing telcos can bring you right now over existing copper && at a vaguely affordable price && while being profitable enough for them to continue deploying it.
Now, in exchange for this non-switchability (you aren't "making calls" with DSL, it's basically like having a big fault-tolerant null-modem cable between you and the terminating equipment), the telcos are supposed to open up their racks at reasonable cost so other ISPs can come in and give you a choice of whose service you're plugged into. Yes, this part has been getting a bit screwed up, but that's a political issue; it's hard to imagine it working another way technologically... unless they'd done something like electricity 'deregulation,' and set it up so you'd *always* be using the telco's equipment, backbone, netblock, etc., and choosing which ISP to pay the equivalent of your 'generation charge' to. If you think about it for a moment, you'll realize that'd work roughly as "well" for telecom as it has for electricity, so perhaps it's a good thing they didn't try it that way.
So the real question is not, "Why do we have to buy DSL instead of 256K modems?," it's "Why do we still bother with 'voice' circuits at all, when everything could be 100% digital and routable, with Vonage-style boxes at the NID of the homes?"
It's 2003, and it'd make the most sense for the telcos to become 'data utilities,' in competition with cable, wireless, and third-party fiber-stringers...
Meanwhile, of course, cable is practically unregulated, so you get your local monopoly with that, and absolutely no ISP choice (which would be technically 'expensive' anyway, giv
Re:56k gateways (Score:3, Informative)
ADSL is only available in certain areas - but there is a 3gig monthly cap. some guys can go through that in a day if they wanted to, and the service is being oversubscribed so quickly that the transfer rates are becoming dysmal. The only advantage is the 24x7 online connectivity (although they say that this is not guaranteed)
So most subscribers pay for 56k access (and we do pay for every local call made)
That pretty much describes the situation in Germany, up until two years ago. Barbaric. The weird thing is, the locals just never understood how badly Deutsche Telekom was abusing them until broadband came along and made it perfectly obvious how far the country was going to fall behind if things didn't change fast.
Local calls still carry toll charges, it's so stupid, as if the bandwidth needed to carry a voice call actually cost anything measurable these days. It's also still pretty much impossible to get flat rate 24/7 dialup access, as Canada has had since about 1995. So if you aren't in an urban area, you are still a digital hillbilly, you connect to the internet only on special occasions.
Re:possible to hack cable/adsl routers? (Score:1, Informative)
And these boxes run popular free *nices (linux, free/openbsd,...)
http://www.soekris.com
Re:possible to hack cable/adsl routers? (Score:2, Informative)
DirecPC server? (Score:4, Informative)
Re:56k gateways (Score:3, Informative)
>You have never worked on any embedded system, for pay or otherwise.
Be nice. I think what the author says is true... from the average Linux hacker's perspective, an embedded platform is NOT readily hackable.
Plus he will have no documentation from the manufacturer. The manufacturer likely modified uClinux and possibly BusyBox in some undocumented manner, to "save space".
I just finished a project where I added some CGI GUI's and a dynamic DNS client to a webcamera with embedded Linux. I couldn't have done it if it was not Linux inside, but it was a bear. When you don't know "what works" on an OS variant, trial and error gets old real fast...
Dammit, where can I get one?!?! (Score:5, Informative)
Now I hear about this, which to me sounds like a Holy Grail, and I can't seem to find it anywhere. The only place I can find it is one of those shady dealers operating on Amazon. There has to be somebody slightly more reputable with some for sale, or at the very least something else to let me compare prices!
Re:56k gateways (Score:3, Informative)
It should be relatively simple to set up, say, PPPoE on one of the ports, a connection to a LAN on the other. Then write a simple script that watches the PPPoE connection status, and dials the modem if the PPPoE has been unable to connect for a certain amount of time.
The device would obviously have control of its own default gateway, which would solve that issue. Would the failover be transparent? Not quite, open connections would break. But it is simple, and would provide service through a DSL blackout.
Samping (Score:5, Informative)
The limitation you refer to has very little to do with managing crosstalk. What actually happened is that the phone company was maximizing the number of channels they could fit on a single wire by using a technology called Frequency Division Multiplexing (FDM).
Since an average voice conversation has a bandwidth of about 2KHz, they built in a low-pass filter with a cutoff somewhere in the vicinity of 3KHz. This means they can heterodyne the channels, each (roughly)3KHz wide, onto a single wire.
Now, this means that the data rate (in terms of zero crossings per second (the original meaning of baud) is limited to about 2400. The "high speed" modems, all the way up to 56K, have a baud rate of 2400. This is a hard limit due to the phone company hardware.
What changed is the number of bits per baud. A 56K modem might use as many as 24 bits per baud, assuming the line is clear enough. The number of bits per baud is capped by the noise floor of the signal, which is also why you won't always connect at 56K (noisier lines can't handle the resolution).
In the move to digital networks, the same total channel datarate was designed into the switching systems. I'm not entirely sure the sampling rate and quantization parameters of these systems, though.
Dammit, where can I get one?!?!-3COM. (Score:1, Informative)
Re:56k gateways (Score:2, Informative)
Re:Dammit, where can I get one?!?! (Score:2, Informative)
I've been doing this for at least the last five years. I use a 3Com 3C886 56K LAN Modem: 4-port (+1 cross-over) hub, DHCP, NAT, Weblett access, etc.) firewalled by a Netgear FVS318 Firewall/router.
I regularly run at least three PCs on this connection, and have had up to six Internet connections up at a time with no practical loss of speed (seat-of-the-pants benchmarking - the only kind that counts in the real world).
The best part of using one of these rather than a standard modem is the elimination of all that PPP nonsense. The ethernet connection is much easier to setup and manage. Also, I have noticed that with using the LANmodem, I have fewer disconnects than I did with my modem.
The downside to the 3Com product is its cost. I wish the Actiontec had been around when I got my 3Com - it's a third the price. And with a hub or switch, who needs more than one port anyway.
I'm going to be looking into getting one of these for each of my friends and relatives who, like me, cannot yet afford broadband.
Re:Dammit, where can I get one?!?! (Score:2, Informative)
Re:Compatability vs. Requirements (Score:2, Informative)
When you plug it in, it defaults to 192.168.0.1 (and 2) and if you setup your PC to pull an address from DHCP, you'll get and address from the box. Then, you can simply http://192.168.0.1 from a Mozilla (or whatever flavor browser you like) and configure it.
They ship this stupid piece of software called "Router Buddy" which has these lame graphics, opens a Web Browser session for you and then adds a Toolbar link to XP so that you can easily connect to the router with a single click.