Why is ADSL so finicky?

Sorry, this is just a letting-off-steam grumble..


Why is ADSL so finicky?

For the past few months my broadband connection, which was previously
rock-solid, has been somewhat temperamental. It started off that
occasionally the router would lose sync, and take a little while to come
back up, before continuing merrily. I could live with that.

Then it happened that the router would lose sync, and would only come
back up again after having been physically powered-off for a few minutes.

So, as recommended, I tried using the master test socket, sometimes with
a little improvement, sometimes not. My ISP has said that line tests
revealed nothing wrong with my line. So I bought another router (prices
fortunately having dropped further in the meantime), and it was happy
for a couple of months.

But now I'm in the situation where my new router has not only started to
suffer the same problems as the first, but has recently almost completely
given up the ability to achieve sync in the first place (although, just
occasionally, it surprises itself into activity ..for a short period).
The old router has been dug up, and usually manages to sync quickly, but
again flails around if (*when*) it loses sync. To make things worse,
this old router has developed a habit of hissing relatively noisily,
making it unsuitable for leaving on overnight. And finally, it's now
come to the stage where the router can only keep sync for about 6 - 8
minutes at a time, before, again, having to power-off (in this case,
yanking the power line out - just how much would it have cost them to
add an on/off switch <sigh>?) for a few minutes before starting again.

Both routers use slightly different versions of the Conexant firmware
which I suspect is familiar to many of us (the new router seems to have
the latest firmware available for it). Is this generally a reliable
setup, or are some ADSL router-modems somewhat better than others?
(Or are they pretty much just all near-identical equally-crap commodity
items, all based on the the same chipset?)

The other possibility, of course, is that there may be something less
than ideal with the installed (when built [1]) telephone wiring within
my flat, although telephone service works just fine on both the main
socket and pre-wired extension. But as I said, using the master test
socket only seems to make a difference occasionally, which may just be
pure luck.

As you can imagine, I'm starting to find ADSL's finickiness as to when
it will and will not work rather exasperating.. :-(


[1] In the case of modern flats with pre-installed telephone wiring, do
BT install all of the wiring in the flat, or just to the master socket,
leaving any extensions to the (possibly less-professional?) builders?



Would asking my ISP to screw my line back down to 1Mb or 0.5Mb (if it is
possible to do such things now) be likely to make any difference?

What about Telewest cable? Obviously you're then stuck with a single
supplier, but is cable broadband any more reliable/less finicky than
ADSL? (And can you still use dial-thru call services with a Telewest
line?)

--
David M. -- Edinburgh, Scotland.--[en, fr, (de)]--[reply-to valid <365d]
* Please trim quotes & interleave reply for readability, don't be lazy *
* Please feel free to help me by correcting my foreign language errors *
*Filter triggers: No-context, excess-quoting, slug-trails, zero-content*

On Tue, 06 Jun 2006 20:14:47 +0100, David M <(E-Mail Removed)> wrote:

> Sorry, this is just a letting-off-steam grumble..
>
>
> Why is ADSL so finicky?
>
> For the past few months my broadband connection, which was previously
> rock-solid, has been somewhat temperamental. It started off that
> occasionally the router would lose sync, and take a little while to come
> back up, before continuing merrily. I could live with that.
>
> Then it happened that the router would lose sync, and would only come
> back up again after having been physically powered-off for a few minutes.
>
> So, as recommended, I tried using the master test socket, sometimes with
> a little improvement, sometimes not. My ISP has said that line tests
> revealed nothing wrong with my line. So I bought another router (prices
> fortunately having dropped further in the meantime), and it was happy
> for a couple of months.
>
> But now I'm in the situation where my new router has not only started to
> suffer the same problems as the first, but has recently almost completely
> given up the ability to achieve sync in the first place (although, just
> occasionally, it surprises itself into activity ..for a short period).
> The old router has been dug up, and usually manages to sync quickly, but
> again flails around if (*when*) it loses sync. To make things worse,
> this old router has developed a habit of hissing relatively noisily,
> making it unsuitable for leaving on overnight. And finally, it's now
> come to the stage where the router can only keep sync for about 6 - 8
> minutes at a time, before, again, having to power-off (in this case,
> yanking the power line out - just how much would it have cost them to
> add an on/off switch <sigh>?) for a few minutes before starting again.
>
> Both routers use slightly different versions of the Conexant firmware
> which I suspect is familiar to many of us (the new router seems to have
> the latest firmware available for it). Is this generally a reliable
> setup, or are some ADSL router-modems somewhat better than others?
> (Or are they pretty much just all near-identical equally-crap commodity
> items, all based on the the same chipset?)
>
> The other possibility, of course, is that there may be something less
> than ideal with the installed (when built [1]) telephone wiring within
> my flat, although telephone service works just fine on both the main
> socket and pre-wired extension. But as I said, using the master test
> socket only seems to make a difference occasionally, which may just be
> pure luck.
>
> As you can imagine, I'm starting to find ADSL's finickiness as to when
> it will and will not work rather exasperating.. :-(
>
>
> [1] In the case of modern flats with pre-installed telephone wiring, do
> BT install all of the wiring in the flat, or just to the master socket,
> leaving any extensions to the (possibly less-professional?) builders?
>
>
>
> Would asking my ISP to screw my line back down to 1Mb or 0.5Mb (if it is
> possible to do such things now) be likely to make any difference?
>
> What about Telewest cable? Obviously you're then stuck with a single
> supplier, but is cable broadband any more reliable/less finicky than
> ADSL? (And can you still use dial-thru call services with a Telewest
> line?)

Maybe BT doing MaxDSL testing?

Clive

David M wrote:

> Is this generally a reliable setup, or are some ADSL router-modems
> somewhat better than others? (Or are they pretty much just all
> near-identical equally-crap commodity items, all based on the
> the same chipset?)

Seen different versions of the Conexant s/w in a number of routers,
1-port and 4-port with no problems. Someone commented about having
disconnections since the exchanged was "Maxed" but checking 2 office
routers in other parts of the country, one had been online 28 days
and the other, 22 days, but they did happen to be little-used and
on only 500 kbps service (from MN). Never seen any reports of some
chipsets being better than others, though people spending 100+ may
try to argue/justify them having something "better" (pah!)

As for whether this is down to being cheap units, I saw a Draytek unit
for 60 quid, but if the problem is your line or at the exchange end, it
will be money for nothing. I've just seen a Westell for 15 + delivery
(sorry, I might as well have that, given they can go for 130 or so) so
it might be worth looking around for a bargain, but don't raise your
hopes too high that paying more will make much difference.

[ my cheap and nasty (Conexant) is showing 8128/448 right now !! ]

--
Change to DSL Max the way I did: switch ISP <http://www.dslmax.info/>

On 6-Jun-2006, David M <(E-Mail Removed)> wrote:

> Why is ADSL so finicky?

Could be a distance from the exchange problem, ok if
you live next door to the exchange.

One might start to suspect that increasing uptake of BB
might be part of the problem. Like an immediate post war
200 pair PVC street cable, with a 1 foot twist pitch, is
going to give cross talk problems when half the lines
are carrying high frequency BB carriers. Most of the
street cabling was installed (and has since deteriorated)
long before BB was ever thought of, back the days when
300 baud acoustic couplers were hot new technology.

BT's failing was not to capitalise on owning the ducts,
they could have pulled in fibre to the Curb, while the
competition had gangs of Irish navvies laying green
ducting, and creating rush hour gridlock in the process.
BT also had, at the time, a monopoly on blown fibre.

I see trouble ahead, not to mention not enough,
non-interfering Wi-fi channels, so everyone starts
jamming each other.

On 6 Jun 2006, (E-Mail Removed) wrote:

>so everyone starts jamming each other.

Except those who are happy with "untidy" cables, like me. Also I don't
drive so never affected by jams, but then again, no cable, as this is a
mostly rural area, thus no cable for a long way, across the plains. PGM

David M wrote:
> Sorry, this is just a letting-off-steam grumble..
>
>
> Why is ADSL so finicky?
>
> For the past few months my broadband connection, which was previously
> rock-solid, has been somewhat temperamental. It started off that
> occasionally the router would lose sync, and take a little while to come
> back up, before continuing merrily. I could live with that.
>
> Then it happened that the router would lose sync, and would only come
> back up again after having been physically powered-off for a few minutes.
>
> So, as recommended, I tried using the master test socket, sometimes with
> a little improvement, sometimes not. My ISP has said that line tests
> revealed nothing wrong with my line. So I bought another router (prices
> fortunately having dropped further in the meantime), and it was happy
> for a couple of months.
>
> But now I'm in the situation where my new router has not only started to
> suffer the same problems as the first, but has recently almost completely
> given up the ability to achieve sync in the first place (although, just
> occasionally, it surprises itself into activity ..for a short period).
> The old router has been dug up, and usually manages to sync quickly, but
> again flails around if (*when*) it loses sync. To make things worse,
> this old router has developed a habit of hissing relatively noisily,
> making it unsuitable for leaving on overnight. And finally, it's now
> come to the stage where the router can only keep sync for about 6 - 8
> minutes at a time, before, again, having to power-off (in this case,
> yanking the power line out - just how much would it have cost them to
> add an on/off switch <sigh>?) for a few minutes before starting again.
>
> Both routers use slightly different versions of the Conexant firmware
> which I suspect is familiar to many of us (the new router seems to have
> the latest firmware available for it). Is this generally a reliable
> setup, or are some ADSL router-modems somewhat better than others?
> (Or are they pretty much just all near-identical equally-crap commodity
> items, all based on the the same chipset?)
>
> The other possibility, of course, is that there may be something less
> than ideal with the installed (when built [1]) telephone wiring within
> my flat, although telephone service works just fine on both the main
> socket and pre-wired extension. But as I said, using the master test
> socket only seems to make a difference occasionally, which may just be
> pure luck.
>
> As you can imagine, I'm starting to find ADSL's finickiness as to when
> it will and will not work rather exasperating.. :-(
>
>
> [1] In the case of modern flats with pre-installed telephone wiring, do
> BT install all of the wiring in the flat, or just to the master socket,
> leaving any extensions to the (possibly less-professional?) builders?
>
>
>
> Would asking my ISP to screw my line back down to 1Mb or 0.5Mb (if it is
> possible to do such things now) be likely to make any difference?
>
> What about Telewest cable? Obviously you're then stuck with a single
> supplier, but is cable broadband any more reliable/less finicky than
> ADSL? (And can you still use dial-thru call services with a Telewest
> line?)
>

If your ADSL is disconnecting every few minutes, and you've eliminated
your internal wiring & set-up, then your ISP really, really should
accept a fault to get the line tested. It could be all sorts of things -
I was in a similar situation recently and when the BT engineer came
out, it transpired that there were some joint boxes that had gotten
water in & been quietly corroding the copper away... not ideal if you're
running MaxDSL .

Which ISP are you with?

Of course, since you've used two routers with the same chipset, it could
just be that they've developed the same fault. Conexants are notoriously
cheap and nasty; although some people swear by them, I've had several
fail on me in quick succession. Other popular chipsets are TI (routers
like ZyXEL, MicraDigital), Sangoma, and I think Broadcom do one as well.
Definitely a difference between them.

If you can get details of SNR/Margin, attenuation, sync speeds, etcetera
from your Conexant (generally they're pretty good for reporting this
sort of thing), and an idea of the variance of them (SNR especially),
then that can give you ammo when you're speaking to your ISP about faults.

Switching down to a lower speed might help if it's a line problem; then
again, it might not. Best looked at as something to try if all else
fails (personally, I'd try MaxDSL before that, but I like my speed. If
worst comes to worst, you can always get Zen's 288-synching DSL).

IIRC, typically for new builds the builders install the internal wiring,
and present it to BT who connect it to their network. But don't quote me
on that .

ADSL is a more complex technology than cable, and it works over a
network that wasn't really designed for high data transmissions, so
there are all sorts of things that can go wrong. Most of them can be
fixed, the majority of the time... the hard part is working out what's
wrong, and getting your ISP to listen (if their tech support happens to
be really cr*p)...

xF,

....Nick

David M wrote:

>
> Why is ADSL so finicky?
>

because its endeavouring to cram many Mbits/s of digital data down
wiring designed to handle 4 kHz of analogue speech.

If you had attenuation and SNR margin data we may have a clue about the
line and signal strength. Prewired sockets may have been done by an
electrician with no clue about twisted pairs etc, also cramming lots of
wiring into the same duct may lead to more crosstalk than separate
dwellings would see.

There are a few chipsets around that behave differently in different
situations and with different DSLAMs. If one misbehaves try another.
Most ADSL problems turn out to be at the end user's end, FWIW.

Phil

"David M" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
| Sorry, this is just a letting-off-steam grumble..
|
|
| Why is ADSL so finicky?
|

It's not. It's a solid and robust technology that works very well over a fragile
phone network never designed for such use.
If you have a sync problem then there is a fault. It's that simple. Don't blame
ADSL for your ISP's inability to get it resolved.

Nicholas Thomas wrote in uk.telecom.broadband
about: Re: Why is ADSL so finicky?

> If your ADSL is disconnecting every few minutes, and you've eliminated
> your internal wiring & set-up, then your ISP really, really should
> accept a fault to get the line tested.

I'll check the master socket again to see if that makes a difference,
before trying to report a fault again, but as you can imagine I'm not keen
on dragging ethernet cable all around the house every so often.. :-(


> Which ISP are you with?

IDNet, who generally seem quite helpful when it comes to support.


> Of course, since you've used two routers with the same chipset, it could
> just be that they've developed the same fault. Conexants are notoriously
> cheap and nasty; although some people swear by them,

...whereas others swear at them? ;-(

That was rather a worry at the back of my mind.

> Other popular chipsets are TI (routers
> like ZyXEL, MicraDigital), Sangoma, and I think Broadcom do one as well.
> Definitely a difference between them.

I'll bear these in mind, if I do need to replace my router.

> If you can get details of SNR/Margin, attenuation, sync speeds, etcetera
> from your Conexant (generally they're pretty good for reporting this
> sort of thing), and an idea of the variance of them (SNR especially),
> then that can give you ammo when you're speaking to your ISP about faults.

Typical figures from the last time the line was up:

Down Up
SNR Margin 36.1 30.0 dB
Line Attenuation 9.1 8.5 dB

Data Rate 2272 288 kbit/s

All seemed constant, apart from downstream SNR, which generally was
around 30 - 36, but perhaps 1 in 8 seconds would drop to 24 - 28 briefly
before rising again. Just before it died, it claimed to suddenly drop
to -9 (?!) with absolutely no warning and then lost sync entirely.


> IIRC, typically for new builds the builders install the internal wiring,
> and present it to BT who connect it to their network. But don't quote me
> on that .

Ah. Do BT check the workmanship of what they're presented with, or do
they just take it regardless? Can't help but think this is a recipe for
problems if the internal wiring has been a bit of a 'bodged job'.. :-(


> ADSL is a more complex technology than cable, and it works over a
> network that wasn't really designed for high data transmissions, so
> there are all sorts of things that can go wrong.

This is true. It's probably a miracle that something like ADSL works at
all, over a carrier only marginally more sophisticated than wet string..
It seems not so long ago that we were amazed that it was actually
possible to squeeze 56 kbit/s out of a phone line..


> Most of them can be
> fixed, the majority of the time... the hard part is working out what's
> wrong, and getting your ISP to listen (if their tech support happens to
> be really cr*p)...

That _is_ the hard part, working out where the problem lies.. :-(

(and I don't really want to spend a small fortune on an armoury of
routers and filters to do so (yes, I have tried changing the filters a
few times as well))


Thanks for your advice (and to everybody else who replied),


David.

--
David M. -- Edinburgh, Scotland.--[en, fr, (de)]--[reply-to valid <365d]
* Please trim quotes & interleave reply for readability, don't be lazy *
* Please feel free to help me by correcting my foreign language errors *
*Filter triggers: No-context, excess-quoting, slug-trails, zero-content*

On 7-Jun-2006, David M <(E-Mail Removed)> wrote:

> Ah. Do BT check the workmanship of what they're presented with, or do
> they just take it regardless? Can't help but think this is a recipe for
> problems if the internal wiring has been a bit of a 'bodged job'.. :-(

AFAIK BT does not check what they are presented with, a source
of problems with new multi-occupancy builds, such as hotels,
hospitals etc. Of course BT will quote to do the installation and
provide the PBX, phones, wiring, maintenance contract, but at
a price that generally makes them uncompetative.
One thing that the cowboys get wrong is that there is an A and
a B wire, and when you go round with your EagleHawk pocket
tester, half the sockets are wired arse about polarity.
Then there is the split pair problem, less common nowdays
with tighter twist pitch and better colour coding. Here one
wire of a pair is paired with one wire from a different pair, and
visa versa.
Leaving the common remaining problem, wires not properly
punched down into the Krone IDC strips, giving a bad or
intermittent connection. The cowboys tend to buy a bag
of platic punch down tools and hand them arround to temporary,
couldn't care less, installers, who are only there for the contract.
But the bean counters like them, they are the cheapest quote.