WinDSL Coming?

A number of people have written in in the last day or so regarding Motorola's rollout of software-based DSL modems. Apparently, this wil reduce the cost of the modems by 30-40%, meaning that they can put DSL into the lower-end of machines. I stand corrected - they aren't modems, they are bridges/routers - and I must be blind, because Linux support was specified in the release. IMDUM.

Comments

Dividing Work Between Main CPUs and Peripherals

[billstewart]

Whenever you divide work between different boxes, you've got to think about what functions you need to perform, and what resources you'll consume performing them, and what resources you'll consume with the communciation, which is often the hard part unless you split the work at the right place.

• Electrical functions obviously belong to the DSL board.
  
• Raw CPU speed is cheap - put a DSP on the board and you can burn all the CPU cycles you need, as long as you don't need much interrupt handling or memory bandwidth. The low-level functions belong down on the DSL board.
  
• The handoff between the DSL board and the PC should probably be Layer 2 frames (an AAL-5 frame looks about the same as an Ethernet packet or Frame Relay frame) (unless you really *want* to hand ATM cells to the PC for some reason.) If the DSL board is internal to the PC, this is clean and easy; if it's external, you either need some kind of Ethernet bridging (#insert risk-of-non-standardness) or maybe a USB interface. If the DSL board is internal, and you interface at some other functional level, you need to be careful to avoid interrupting the CPU to death, starving the DSL waiting for interrupts, and otherwise being a bad neighbor.
  
• Routing, NAT, Firewalling, and IP in general take more memory and intelligence - you could implement them in the DSL box, which is convenient for users who don't like installing hardware or complex software, but moving them to the PC isn't a bad thing - it lets you do much more sophisticated router things, and really isn't that much more work for the PC - as long as the OS has a decent IP implementation, as opposed to some highly lame non-Unix-based products out there which will remain nameless due to professional courtesy.
  

But DSL doesn't support the end-user's needs - it also supports the DSL carrier (Layers 1 and 2) and the ISP (Layer 3) during installation , long-term operations, and service failures.

• Diagnostics for the DSL functions really need to run even if there's no working PC. Obviously an internal board needs electricity, but it's nice if some basic handshake functions can answer from a board-based controller - but it doesn't take much intelligence to do this. (On the other hand, you could also implement this in a "reboot your PC in MSDOS mode" boot floppy.) If you are running diagnostics on the PC, you either need some custom interface, or else you need to make them use the same Layer 2 packets you use for data transfer.
  
• Diags for the IP vendor have similar issues, though you need to use them when the system is up and running. Good DHCP client support is your friend. Broadcasts and Bootp are also your friends. As long as the board allows promiscuous receiving (which may be an issue for some external devices) you can build the rest of the handshakes you need.
  
• Diags are most critical during installation, but running a high-quality service means you need run-time support as well - things like SNMP or at least PING need to work, and periodic uploads of information like electrical line qualities can be really helpful in preventing failures.
  

Yes they are modems

[Megane]

They might not be able to talk with an old 212 modem, but they are modems. They just happen to operate in a higher frequency band than POTS modems. The higher the base frequency, the more bandwidth available per octave of frequency.

In fact, even ISDN has to do analog modulation. It just uses a much simpler form of modulation which can easily be run through repeaters for longer distances from the CO. ISDL is DSL protocols over ISDN modulation, and using ATM instead of the PSTN to get out of the CO.

Bad idea

[kwsNI]

Ok, there are a few reasons I don't like this. Most companies (at least where I live) are providing the DSL modems for free when you sign up for a 1-year contract for DSL. This means they can give me a cheaper (and Win-ONLY) modem. If they are anything like Winmodems, I doubt that anytime during the lifetime of DSL will they remove all of the bugs. I work for a very large computer company and we still have a large amount of problems with Winmodems and some online services (*cough* AOL).

kwsNI

Re:Bad idea

[pfcgibson]

I wholeheartedly agree. I work for a helpline and winmodems cause a lot of stress. It's not a whole lot of fun trying to explain to someone that they just have a pretty crappy modem and should expect it to be a little flakey. I too got in on the free modem when you sign up and I would not have been able to let myself take part in that if they were using winDSL modems. Its another move towards cheaper, faster, crummy technology that we are expected to put up with. I'd much rather that the effort be put into making more expensive hardware better and less expensive than shooting for these drastic price drops.

Re:Not a bad thing

[(void*)]

But from an engineering point of view, this is bad. The driver should be well-separated from the CPU, so that the OS does not get too complicated (read: stable, bug-free, predictable). The protocols would be cleaner, so that more OSes can use the peripheral. So that the modem is not tied needlessly to one OS, or certain types of functionality. From the users perspective, this is better. It is the users computer. He/she should *know* what he is in for when installing such a thing. Heshe should know that with such a modem, running Quake through the modem might not be such a good idea. Yet these design issues are just glossed over for something "cheap". Is this way way to treat a consumer, however clueless they may be?

And BSD? And ____?

[Booker]

Ok, I run Linux, so I'm glad to see more things like this that will support it (even though I wouldn't be caught dead actually using one of these...) but still. Here's the obligatory "What about _other_ operating systems?"

I really doubt that this will be anything but a binary driver. Yes, it's their product, and they can do what they want with it. But it does not give me a warm fuzzy feeling. :)

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Re:Yeah, that whole 5-15% OOOOHHHHH!!!!

[Rombuu]

You know, even 5-15% translates to a hell of a lot of money when you consider how large the computer market is...

Yeah, but you aren't dealing with the whole computer market, just PCs.

Well, really you aren't dealing with the whole PC market, just home PCs (since its pretty damn rare to see a modem in an office)

And then you are only dealing with home PCs with DSL access available.

So now you think they really care about 5% of the home PC DSL enabled market?

Cisco

[dragonfly_blue]

I got a "free" Cisco 675 external DSL modem when I signed up for DSL with USWest. I've worked with a couple other types of DSL modems, and let me just say, this thing rocks.

It is highly configurable, USWest sent about four different manuals with it (RTFM, indeed!). It's given me some exposure to Cisco hardware, good experience with Telnet, routing tables, ports, and the CBOS (Cisco Broadband Operating System.) Also, it works on anything you can connect to an Ethernet hub or switch, Linux, Mac, Windows, BeOS, you name it. I've had 6 machines hooked up to it at once, with nary a glitch.

I'd be skeptical that a software modem could provide a very robust operating scheme. The 675 has never crashed, but a modem dependent on your WinBox to run just might.

DSL modems do exist...

[Cato]

http://www.whatis.com/modem.htm disagrees with you - DSL modems are sometimes called by an obscure TLA, but since they take digital in on one side (i.e. ethernet or USB) and put analogue out on the other side (taking care not to disturb the analogue voice channel), it seems to me that 'DSL modem' is a fair term. Nortel' Shasta division make DSLAMs and agree too.

The whole modem / non-modem distinction is somewhat arbitrary - after all, ultimately every digital networking device has to put signals on a wire or fibre, and those signals are ultimately analogue. The only difference is whether there is a simple encoding or a complex encoding, and whether there is an analogue-only mode for that channel, or if the link is expected to always interpret these analogue signals as digital.

Let's just agree that small devices that connect you to phone-like wires are called modems (unless they're called ISDN TAs : )

Technical accuracy?

[Dave Scherer]

Okay everyone, repeat after me. There IS NO SUCH THING AS A DSL "MODEM". "D" in DSL is for digital.

The following is quoted from this 3Com white paper

For ADSL, the most talked-about xDSL technology, there are two competing modulation schemes: carrierless amplitude phase (CAP) modulation and discrete multitone (DMT) modulation. CAP and DMT use the same fundamental modulation technique--quadrature amplitude modulation (QAM)--but differ in the way they apply it.

QAM, a bandwidth conservation process routinely used in modems, enables two digital carrier signals to occupy the same transmission bandwidth. With QAM, two independent message signals are used to modulate two carrier signals that have identical frequencies, but differ in amplitude and phase. QAM receivers are able to discern whether to use lower or higher numbers of amplitude and phase states to overcome noise and interference on the wire pair.

Sounds like a MODEM to me!

you are all missing the point

[inquis]

All the comments on this thread are all like "win-anything is going to suck processor cycles, so this software DSL modem is going to blow." The fact that everyone is missing is that Linux support was explicitly stated in the press release. Now, what does this mean? I put forth this hypothesis. Let's say Motorola wants to get a chunk of the forthcoming "internet appliance" market, and they see that the future is clearly broadband. They want to make a cheap broadband communications device that they can sell to every company that makes an "internet appliance". What is their target market? CERTAINLY NOT WINDOWS SYSTEMS!!! Honestly, who is ever going to create a win32 based embedded system?? Linux is the natural choice, and if Motorola does not realize this, then they are shooting themselves in the foot. In fact, I bet that they could care less if a wintel box would even boot with the thing in as long as the Linux boxes will work well with it in. My predictions: 1. Motorola is going to get a large pile of money. If (some would say when) this "internet appliance" paradigm gets off the ground, its rise will probably coincide with the rise of the cheap broadband that would be necessary for these devices to work. Since you are trying to keep costs low on these appliances, you are not going to want to by components that are at a premium. Instead you buy a bunch of cheaper things so you can keep your prices low. If Motorola is first out of the gate with this they will have people practically throwing cash at them from all sides. 2. Linux performance will not be as bad as everyone fears. I admit that winmodems suck badly, really really badly when compared to their hardware counterparts. ON A WINDOWS MACHINE. Seriously, I have not seen a win32 machine (except for a few tweaked out NT boxes) that ever have had enough spare resources AT ANY TIME to be able to handle the winmodem overhead satisfactorially, much less a home system. However, we are not talking home systems, we are talking IAPPLIANCES with dedicated tasks. Open your eyes people; they are not trying to sell this to you. The inquisitor has spoken.

Slashdot tip 'o the day

[Anomalous Canard]

When previewing, use the back button before repairing the damage or submitting rather than editing in the window on the preview page or submitting from there. The editing tool on the same page as the preview eats things when it shouldn't. It used to convert < into < for example, but now that's fixed. Instead, it eats HTML tags.

Anomalous: inconsistent with or deviating from what is usual, normal, or expected

Stop them before they get there

[bfree]

Lets us all tell them to fsck off. They are just helping AMD etc. sell more high speed processors ("with todays 550MHz+ processors blah blah blah"). Let's not suffer lower frame rates in online games for the sake of £50, and lets not suffer OS incompatible hardware devices for the sake of it. Please someone with the bandwidth begin a petition now to tell them to fsck off!

Read the motorola press release

[Carnage4Life]

Here's the motorola press release and Yes, there'll be Linux support.

Re:Windows-Tyize

[DustyHodges]

Unfortunatly, not that much of the market isn't windows. If you want to make a cheap piece of hardware by using software, you have to focus on the Win side to make any money... Software based isn't going to do it for anyone else anyway... Linux users are smart enough not to pay good money for software based modems. But eventually, someone on LinModems will post their drivers for it. It's bound to happen. I truly think that this is no big loss for any other community. As I can verify, being the owner of an LT Win modem, software based modems are pieces of shit. If I were a more informed geek at the time I had purchased my machine, I would have made sure to get a hardware based modem... When crap is being peddled to the masses, why be upset that they aren't marketing to you? Software based modems are, quite simply, the fast food of connectivity hardware. If you want something that is any good for you, you simply have to go with something else. Just my opinion, Dusty Hodges

Re:Performance Hit

[Thomas Charron]

The best example I can say is take these steps, and you can quite literally *WATCH* the software begin to fail simply becouse of CPU resources..

1) Install a 56k Winmodem in a Celeron 300 Machine running Windows NT. (Windows NT is simply becouse of those lovely beeps it'll make to tell you bad things are happening.. Adds affect)

2) Connect to the net, download RealVideo

3) Play *ANY* RealVideo designed to run on a 56k connection (Usually encoded for 42 or 44 something)

4) Listen top the beeps FLY! CRC errors off the chart. That's what happens with the software based drivers.. No resources, buffer overflows about, and CRC errors (Beeps) start playing a fast beat dance song for you..

You can be wrong, but don't be bitchy too..

[consume]

Please take a second and read T1.413, which is the ANSI standard for ADSL.

OR you could just read Newton's Telecom Dictionary, under Modem:
"The term "modem" is also applied (and correctly so, in the purely technical sense) to ISDN TAs (terminal adapters), ADSL TUs(Terminating Units), line drivers and short-haul modems.

Instead of using a shift-keying encoding (typically Quarternary Phase Shift Keying for 28.8kbps and higher) xDSL uses CAP (Carrierless Amplitude Phase) or DMT (discrete multi-tone) to MOdulate the digital signals onto an analog medium and DEModulate the analog signals back into ATM cells or Ethernet frames.

Keep attempting to be technical. We'll all still be here when you get back...

550 MHz?

[jonnythan]

They claim that they should work in any system that's at least 550 MHz. If you need that much processing power for a DSL modem to be hardly noticible (which is what I suppose they mean, maybe less than 20-30% processor usage), then can you imagine playing Quake 3 or UT on the net? Just your modem would be pulling a large percentage of your FPS, which would not make these people very happy.

56k WinModems are fine; even though they may be a little buggy, at least the data transfer rate doesn't require a dedicated Pentium II-class chip just to run.

Give me my hardware DSL modem, or the lovely ethernet-based cable modem i'm going to get in a few months.

Oh no, not another Winmodem...

[IO ERROR]

The best thing about Winmodems is you can update the firmware. The worst thing about Winmodems is you can update the firmware. Winmodems tend to be buggy, CPU-hungry beasts whose firmware is updated frequently because of it. They tend to be very unreliable. (Don't believe me? Call up your favorite ISP and ask THEIR opinion of Winmodems.) The article says it'll run fine in a 550MHz system. And they're targeting it at under-$1500 computers? Can you get a Coppermine system for that price, WITH the DSL modem? (Think Gateway, Dell, etc., not parts-from-eBay.) Besides, DSL devices are fairly cheap for the bandwidth you're getting. You have a couple of choices: avoid the issue altogether by getting an EXTERNAL device, like the Cisco 675, or write software drivers for your favorite OS. Will Motorola allow this to be done? Who knows.
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Performance Hit

[NMerriam]

Unfortunately the side-effect of this is that people won't realize they're taking a big performance hit.

Software modems, for the driver problems, aren't that big of a deal on windows because the Modem isn't using much processor time anyways.

But this thing sounds like a real hog -- they couldn't implement it until now because anything below a P3-550 couldn't run it? This sounds like a great way for Intel to sell more processors.

The folks who really appreciate high-speed access (other than Warez d00ds and Pr0n Kings) are gamers, and this is really gonna suck for folks who think they're getting a great deal, only to boot up and wonder why their new P3-1000 is slower playing Diablo 2 than their old P2-233 on a dial-up.

And then of course the driver issues, when Loki comes out with Diablo 2/Linux (maybe?)...

Re:PROPER LINK HERE....

[IO ERROR]

/. is eating HTML tags for breakfast this morning. Let's try it without previewing first:

http://www.corporate-ir.net/ireye/ir_site.zhtml?ti cker=mot&script=410&layout=7&i tem_id=86582
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