Recommendation for a DSL modem

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Hi again Experts,

I have had a Siemens Speedstream 4100 that appears
to have gone belly up. I bought it new about 3
years ago and it hasn't been used a lot, so I
suspect the quality.

Does anyone have a test that proves it is defective?

If you were in my place what would your replace
this Siemens with?


Re: Recommendation for a DSL modem

JD wrote:
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Well, first you have to decide whether you need ADSL2+ or can work with ADSL.

I've only had a couple ADSL modems here. The first one, came as a rental with
my Sympatico account. It ran cool enough, that the unit had no vents, just
a metal box with status LEDs on it. I could leave that running, without
worrying about anything. It lasted as long as I had the account (years and
years), and because it was a rental, made the supplier a bundle.

My current ADSL modem supports ADSL2+ (it seemed a good idea at the time),
but my service is still capped at 5 megabits/sec. So a plain ADSL modem
would have been sufficient.

I got a Speedtouch ST546v6 and it runs hot. It seems to have a few
regulator chips inside, and has no cooling other than some vents cut in the
plastic. I've mounted a fan next to it, to aid cooling.

The unit is a combined modem/router/switch, with four Ethernet ports. The
firmware is so bad, I run it in bridge mode, and use an external router
that at least I can program with a web browser. There are some
protocols I'd like to turn off on the Speedtouch, but I need to master
a command line interface (with about a hundred different commands available),
to make that happen. Rather than bother with scripting, I just turned off
the router, and used bridged mode to turn the box into a "straight piece of

There seems to be a trend to incorporate modem and router in the same
box. If they put the effort into doing firmware which the end-user could
use, I'd be all in favor of that trend.

So what lessons did I learn ?

1) The product I bought, seemed designed to please the ISP selling it,
    rather than being designed to help the end-user. For example, the
    ISP has the ability to "lock" certain features in the unit, and if
    the user doesn't have the password for that admin level, there is
    nothing you can do. Fortunately, the modem belongs to me, so every
    function is available (even if I'm not interested in spending a couple
    weeks learning the CLI).

2) I really should have insisted on a proper manual, before buying it.
    I assumed I'd eventually find a manual, as the documentation I could
    find seemed a bit brain-dead. The unit does have a web interface,
    but it doesn't appeal to me.

Where should you look instead ? Look for something by TP-Link. That is
a company that clones other designs, and the retail price is quite reasonable.
If it turns out to be a bust, and you hate it, you'd be out a few less
dollars than for the thing I bought.

The TP-Link products may be a challenge to understand (numbering scheme, what
you're getting and so on), and threads on this site may help you.

In the table here, you can see that some of the modems share the
same main chip. Finding a picture and details of what is inside,
should allow you to track down how well that particular chip is known
to work.

There is a piece of software called DMT, that displays stats from
the modem. I haven't tried it on mine, because I don't know if
my operating the unit in bridged mode, makes a difference or not.
What DMT does, is give you some idea how much SNR you have, and
whether your profile can be raised safely or not. For example,
I'm not getting my full 5 megabits/sec, and I think I have
excessive margin that could be converted into usable bitrate.
If I bothered to run DMT, I'd have the necessary proof, to phone
the ISP and get it bumped up. The "versions" of DMT are sorted
according to the modems or chipsets they support. /

The controls on there, may be sensitive to the version of firmware
running in the modem. In some cases, if you're a real enthusiast,
you want to load an older firmware, that supports some of the
sliders in the interface.

So whether you can get statistics from the unit, might be
another slight concern. That gives you some options, if
you're given a profile that is less than what you're paying
for. They do that, as a function of the signal to noise
ratio. They'll turn down the link, in the interest
of guaranteeing it will sync each time you use it.


Re: Recommendation for a DSL modem

On Thu, 27 May 2010 00:36:27 -0400, Paul typed this message:

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OMG!!!  I "had" to buy a Motorola Surfboard for AT&Ts crappy DSL
service.  I was very annoyed that its proprietary to AT&T and required
Microsoft Windows IE or MAC OSx Safari in order to setup the modem with
the service.  

Now you're saying not only do they have the serial number of this modem
but they can also modify the settings and service!!!  SH(t


Re: Recommendation for a DSL modem


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Crack it open and inspect for failed capacitors.  Use a
voltmeter to check power supply voltage.  Observe the lights
on it to see if it appears to boot.  What signs of life does
it show?

Some modems have configuration pages you can access with
your browser (HTTP webpage) if you know the IP #.  One
common default # is so it would link like BUT I don't know if that is the right #
for yours if yours has a config page at all.  The manual
should mention that.

Often a modem will fail from a power surge over the
telephone line.  There might be no visible damage from that
but while it is open look at the components to see if there
appears any damage that could be related.

A true qualifed test that "proves" it is defective is
probably beyond the capability of anyone but Siemens
themselves, rather all you can do is prove that it works or
assume it's dead if you can't make it work.  I haven't even
covered the various issues in labeling something as
defective... since it worked when brand new it isn't likely
to have a factory manufacturing defect but perhaps a design
flaw, poor component lifespan from corner cutting or
component defect, or as mentioned above possibly non-defect
damage from a power surge or overheating if used in a hot

Re: Recommendation for a DSL modem

kony wrote:
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Thank you, thank you, Paul and Kony for these
fantastic answers.
Now all I need to do is to find the time to study

The DSL light does not come on now but I need to
go through
all the cabling and connections to make sure they
are ok.

Back again soon.

Have a great weekend you generous guys :-)

Re: Recommendation for a DSL modem

On Wednesday, May 26th, 2010 at 19:51:30h -0700, JD asked:

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Either a D-Link DSL 320B ADSL/2/2+ modem


or a Linksys AM200 ADSL/2/2+ modem


Re: Recommendation for a DSL modem

In my experience speedstreams are the longest lasting, although in your
case it
appears that you have lost one.

It has been years (since upgrade from 95 to 98) since I've been into
the ss
setup but IIRC there were some diagnostics buried in there.

Re: Recommendation for a DSL modem

edfair wrote:
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Thank you Edfair.

Today I took the modem apart and inside it is
pristine. The capacitors look
perfect and there are no burn- or other distress-
marks anywhere.
Will fiddle some more with it tomorrow.

Hope you enjoyed the weekend  :-)

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