Do some ADSL Modems have trouble with high data rates?

Hi
Is it a problem that some modems lock up when high data rates pushed through
it. Have a 2Mb line and maybe 3 Usenet connections going at 60Kb/s each and
then web browsing with occasional download. After about 15 mins router locks
up, and then does it again immediately after a switch on/off so once warmed
up seems to be a constant problem. Just web browsing is OK. Have another
router (SEG AR601) that has no problems, but I have to move the PC to use
it.

The modem has a Connexant chipset (SOLWISE SAR-804P with Homeplug - the
Homeplug part not the problem as direct Ethernet connection still a problem)
I have tried changing MTU settings on PC & Router to 1500,1492 (default) and
BT's 1458 but still no joy.

thanks

Paul

Paul C wrote:
> Hi
> Is it a problem that some modems lock up when high data rates pushed through
> it. Have a 2Mb line and maybe 3 Usenet connections going at 60Kb/s each and
> then web browsing with occasional download. After about 15 mins router locks
> up, and then does it again immediately after a switch on/off so once warmed
> up seems to be a constant problem. Just web browsing is OK. Have another
> router (SEG AR601) that has no problems, but I have to move the PC to use
> it.
>
> The modem has a Connexant chipset (SOLWISE SAR-804P with Homeplug - the
> Homeplug part not the problem as direct Ethernet connection still a problem)
> I have tried changing MTU settings on PC & Router to 1500,1492 (default) and
> BT's 1458 but still no joy.

The following is very generalist and simplistic, and may not even apply
as you might actually have a hardware problem.

When downloading, computers also have to upload a certain amount of
data, hand-shaking etc. To do this there must be some bandwidth
'spare'. So if three people are downloading large files at the same
time on a finite amount of bandwidth there is bound to be congestion,
simply due to not being able to down AND UP load enough data at once.
Effectively you're simulating a DOS attack on yourself, downloading too
much and taking the upload bandwidth away. Some modems / routers will
handle this better than others.

I'd swap out the routers, and any connectors / wiring, making note of
any different software settings for each one. Run them separately and
note what happens to each, basically trouble shoot the 'bad' modem until
you're certain it's not just some strange software problem. Then buy
another of the 'good' modem.

--
The Caretaker .........

"The Caretaker" <(E-Mail Removed)> wrote in message
news:Gelge.4326$(E-Mail Removed)...
> Paul C wrote:
>> Hi
>> Is it a problem that some modems lock up when high data rates pushed
>> through it. Have a 2Mb line and maybe 3 Usenet connections going at
>> 60Kb/s each and then web browsing with occasional download. After about
>> 15 mins router locks up, and then does it again immediately after a
>> switch on/off so once warmed up seems to be a constant problem. Just web
>> browsing is OK. Have another router (SEG AR601) that has no problems, but
>> I have to move the PC to use it.
>>
>> The modem has a Connexant chipset (SOLWISE SAR-804P with Homeplug - the
>> Homeplug part not the problem as direct Ethernet connection still a
>> problem)
>> I have tried changing MTU settings on PC & Router to 1500,1492 (default)
>> and BT's 1458 but still no joy.
>
> The following is very generalist and simplistic, and may not even apply as
> you might actually have a hardware problem.
>
> When downloading, computers also have to upload a certain amount of data,
> hand-shaking etc. To do this there must be some bandwidth 'spare'. So if
> three people are downloading large files at the same time on a finite
> amount of bandwidth there is bound to be congestion, simply due to not
> being able to down AND UP load enough data at once. Effectively you're
> simulating a DOS attack on yourself, downloading too much and taking the
> upload bandwidth away. Some modems / routers will handle this better than
> others.
>
> I'd swap out the routers, and any connectors / wiring, making note of any
> different software settings for each one. Run them separately and note
> what happens to each, basically trouble shoot the 'bad' modem until you're
> certain it's not just some strange software problem. Then buy another of
> the 'good' modem.
>
> --
> The Caretaker .........
Thanks, There is only 1 PC and 1 Router/Modem. The thing is that the router
never recovers if I stop the downloads, it has to be restarted (actually
switched on/off because the Web Interface is inaccessible to do a 'soft'
restart). How are these routers which claim to be good for up to 8Mb going
to work when we have 8Mb lines?
Paul

Paul C wrote:

> Thanks, There is only 1 PC and 1 Router/Modem. The thing is that the router
> never recovers if I stop the downloads, it has to be restarted (actually
> switched on/off because the Web Interface is inaccessible to do a 'soft'
> restart). How are these routers which claim to be good for up to 8Mb going
> to work when we have 8Mb lines?

It sounds like a faulty modem. Maybe an update to the firmware, if
possible, might fix it.

Personally, if a different one works, as you say, then I'd dump the crap
one and get another of the kind that does work, or move the computer to
use the one that does work.

--
The Caretaker .........

>> The modem has a Connexant chipset (SOLWISE SAR-804P with Homeplug - the
>> Homeplug part not the problem as direct Ethernet connection still a
>> problem)
>> I have tried changing MTU settings on PC & Router to 1500,1492 (default)
>> and BT's 1458 but still no joy.
>

You might try a speed test with all these settings to see if there is any
difference at all and likely not. It's more likely that you will need a
customised setting for your router. I think I have mine at 1433, it's while
since I last mucked around with it.

Steve

On some routers, if you are running several tasks simultaneously the routing
tables get corrupted requiring a reset. Some routers also overheat. Both
were know problems on Netgear, many successive firmware updates seem to have
eased the first problem.
Regards,
Martin